• Valeria Souza

We arrived at Cuatro Ciénegas in 1999, brought by NASA to study it as a model of the sea in the Early Cambrian and possibly early Mars, and what we found was far more fantastic than expected. The San Marcos y Pinos Mountains hold a magmatic pocket in their depths, forcing a deep aquifer rich in viruses, bacteria, and ancient archaea to rise to the wetland, where they form microbial mats and stromatolites. As a result of this "sampling" of a vast gene pool, we observed that each sample is different, yet metabolically complementary. The lineages are highly diverse and generally exhibit long branches, suggesting a lost world that isolated itself from the rest of the world in the mountains and experienced, in isolation, its own evolutionary processes. However, Churince, Pozas Rojas, and Domos del Arqueano are three systems that have been studied over time. Two of them are already dry, and we hope that Pozas Rojas can function as a reservoir and as a "vent," a site where the primary productivity of the deep microbiome can photosynthesize before returning to the depths and, by infiltrating, feed the enormous diversity found in the deep aquifer. It is a tragedy that this aquifer is overexploited, and we hope that new conservation and awareness-raising actions will lead to the conservation of this unique site.

• Irene Pisanty, Facultad de Ciencias, UNAM, México
• Mariana Rodríguez-Sánchez
• Luisa Granados Hernández
• Hilda Flores Olvera
• Helga Ochoterena Boot
• Mariana Hernández-Apolinar
• Pedro Mendoza Hernández
• Xochiquetzal León Ceja
• Arturo Peralta Jiménez

Changes in vegetation in arid and semi-arid areas are slow and infrequent. Species turnover can take so long, hence it has been considered that in deserts successional processes do not exist. However, under certain conditions, for example, when there is a disturbance or when dealing with unstable or forming environments, it is possible to observe processes of colonization and establishment of species over short intervals of time. In the Cuatrocienegas Valley, Coahuila, the hydrological systems have been profoundly disturbed for many years. The Churince system has been drying up for the past 20 years. Consequently, new habitats have opened up, including numerous differential sinkholes (abras) at the bed of the Churince River, and the Churince and Intermedia lagoons, as well as at poza Churince. The colonization rate of these environments depended on the exposure of substrate as the water recedes. In 2004, the Churince lagoon was the first part to lose its surface water. The system desiccated progressively until reaching poza Churince, where the spring that fed the system was located. The colonization of the dry bed of this lagoon has been very slow. Currently, isolated patches of vegetation are evident in the area, with very few species of sparse cover. In contrast, the dry bed of the Intermedia lagoon, which lost its surface water in 2020, has been colonized by various hydrophilic species and subsequently by other species, predominantly grasses, with coverage of up to 100%. Desiccation has led to the evaporation and leaching of mineral salts, including gypsum, resulting in the establishment of specialized vegetation on this substrate. An example of this is the establishment of Nerysirenia incana in nearby areas of the Intermedia lagoon. This gypsophilic herb grows in areas of contrasting stability, with or without a gypsum crust. This crust limits the establishment of seedlings, while the mobile substrate covers adult plants, which may or may not emerge again. The effects of the desiccation of the Churince system are already visible at the landscape level and in the plant communities. Alterations in ecosystem functioning must be evaluated, and efforts to restore springs and wetlands must not cease.

• Luis E. Eguiarte, Instituto de Ecología, Universidad Nacional Autónoma de México, México
• Valeria Souza, Instituto de Ecología, Universidad Nacional Autónoma de México, México

In this talk we will describe the objectives and advances of our ambitious scientific project in the Magellanic region in the Southern tip pf the American continent. This is a large project involving many researchers of Chile, Mexico, Japan, Ecuador and Germany, and our main objective is to develop a detailed baseline to analyze the effect of global change in the regions, using as sensors the animal, plant, and microbial communities in this sensitive geographic area. Recently, not only water and air temperatures have been increasing, but for most years, the austral ozone hole has been increasing in size, and thus the ultraviolet radiation reaching the area has incremented. To analyze this, on one hand we have been setting several new and sophisticated climatic stations in the area, measuring not only basic parameters of the climate, as temperature, precipitation and winds, but also the incidence of different wave-lengths of ultraviolet radiation. On the other hand, our main biological focus has been in the evaluation of the surface microbiome found in different animal and plant hosts: two species of penguins (Magellanic and King), humpback whales, southern sea lion, two species of fishes (salmons and sardines), two species of crustacea (centolla or king crab and munids, a squat lobster), along with the kelp, a brown algae. We have also analyzed the microbial communities of water, soil, and sediments in many localities the area. We have carefully analyzed not only the microbial composition of the microbiomes, but also the expression of the different genes. In addition, we are studying the genomic structure of the host populations in the areas. We will describe in the talk the main results of our analyzes of both penguin species: how that the microbiomes are different between species, given their differences in nesting habits (Magellanic nests in soil borrows, King nest in open air nest) and ecology. We also describe the dynamics in time and spaces of the microbial communities in the surface of the Magellanic penguin in different island and different reproductive times. In addition, we will compare the surface microbial communities in both studied mammals, and in particular discuss the patterns in two different localities in the migration of the humpback whale, from the reproductive grounds in Ecuador to their feeding areas in the Magellan strait. Finally, we will explain the detected high expression of microbial genes involved in DNA reparation and resistance, that we think are responses to the with recent increases in UV radiation incidence in the area.

• Silvia Pajares, Institute of Marine Science and Limnology, National Autonomous University of Mexico, México
• Jorge Rojas
• Guillermo Samperio

Coastal lagoons are dynamic transitional ecosystems influenced by complex hydrodynamic and biogeochemical processes. Their sediments host diverse microbial communities essential for nutrient cycling, organic matter sequestration, and ecosystem stability. However, the taxonomic and functional composition of these communities remains poorly understood, particularly in pristine systems. Here, we used shotgun metagenomics to characterize microbial diversity and functional potential in the sediments of Bahía de San Quintín (BSQ), a minimally disturbed coastal lagoon on the Pacific coast of Mexico shaped primarily by oceanic forcing. Sediment samples were collected across three lagoon sectors (inlet, transition, inner), two habitat types (Zostera marina meadows and unvegetated sediments), and two seasons (relaxed upwelling: October 2021; intense upwelling: June 2022). Despite pronounced environmental gradients and seasonal variability, BSQ sediments harbored a highly diverse and taxonomically conserved microbial community. Over 60% of genera and ~40% of species were consistently shared across conditions, with Gamma-, Delta-, and Alphaproteobacteria, Flavobacteria, and Actinobacteria as dominant taxa. Functional analyses revealed widespread and redundant genes involved in nitrogen and sulfur cycling, suggesting a conserved metabolic core supporting key biogeochemical processes. In contrast, genes linked to metal resistance, antibiotic resistance, and virulence exhibited more heterogeneous patterns. Among environmental variables, only nitrate and Fe(III) significantly influenced microbial community structure, indicating the potential role of additional unexplored drivers. These findings underscore the stability of microbial communities in BSQ sediments, offering a valuable baseline for understanding microbial dynamics and ecosystem function in coastal environments primarily shaped by natural oceanographic processes.

• Devaki Bhaya

The colorful microbial mats in the hot springs of Yellowstone National Park represent stratified biofilms where 16S rRNA diversity has been correlated with environmental gradients of temperature, oxygen and light. These extremophile phototrophic communities are ideally suited to gain deeper insights into how microbial diversity, dynamics and defense strategies are correlated with environmental gradients. In particular, we are interested in how microbial communities cooperate and also how they deal with biotic and abiotic stressors. To do so, we use various bioinformatic and molecular approaches including comparative genomics, diel transcriptomics, metagenomics (based on short and long read datasets) and information gained from single amplified genomes. I will describe our strategies to quantify and understand the role of genomic micro-diversity, horizontal gene transfer, host-phage coevolution and metabolic versatility in these communities. I will emphasize how collaborations with computational and evolutionary biologists has enhanced our understanding of the diversity and dynamics of phototrophic communities and how physical parameters (such as light) and biotic stressors (such as phage attack) shape the microbial world.

Supported by National Science Foundation, Carnegie Institution, DOE Joint Genome Institute, and Environmental Molecular Sciences Laboratory.

• Katia Aviña-Padilla, Cinvestav-Irapuato, México
• Elizabeth Cadenas-Castrejón
• Erika Viridiana Cruz Bonilla1
• Augusto Franco
• José N. García-Miranda
• Gabriela Olmedo-Alvarez1
• Maribel Hernández-Rosales

Cuatro Ciénegas, located in Coahuila, Mexico, is an ancient aquatic system with unique geological and biological characteristics, harboring diverse microbial communities adapted to extreme oligotrophic conditions. This region’s pools and channels, remnants of prehistoric marine ecosystems, provide an exceptional opportunity to study microbial evolution and adaptation. Among the most striking formations are stromatolites, lithified microbial structures that persist over geological timescales. To explore the viral and microbial diversity in these ecosystems, we conducted a metagenomic analysis of a stromatolite and six microbial mat layers from Poza Roja. DNA was extracted and subjected to Illumina deep sequencing, followed by taxonomic classification using BLAST and Kraken2. This approach revealed a complex virome, with a notable presence of giant DNA viruses, including Bodo saltans virus, Tupanvirus deep ocean, Tupanvirus soda lake, Powai lake megavirus, Moumouvirus goulette, and Cotonvirus japonicus. Additionally, members of the Megavirus, Mimivirus, and Moumouvirus genera, as well as representatives of the Mimiviridae family, were detected in both microbial mats and stromatolites, indicating their potential role in microbial community structure. Comparative analyses revealed distinct viral distributions between microbial mats and stromatolites. While some viruses were shared across both environments, others exhibited strong habitat specificity. Several phages, including Escherichia phage vB_EcoM_Bp10, Emaravirus syringae, and Lakivirus lakamhaense, were found exclusively in microbial mats, suggesting a role in bacterial regulation and microbial turnover in these dynamic environments. In contrast, stromatolite-exclusive viruses, such as Ocetevirus paratemnopterygis, Cyclovirus kisikisi, and Alphacoronavirus HKU33, suggest viral adaptations to long-term microbial interactions within stable lithified structures. The presence of Acanthamoeba polyphaga mimivirus and Bodo saltans virus further suggests that giant viruses influence protist populations, potentially playing a regulatory role in microbial trophic networks. To investigate virus-host interactions, we constructed a viral co-occurrence network based on graph theory, where edges represent virus-host associations. This network analysis revealed strong interactions between giant viruses and microbial taxa such as Aeromonas, Gordonia, Acanthamoeba, Vibrio, and Serratia. The presence of these associations suggests that giant viruses contribute to microbial turnover, influence biogeochemical cycles, and modulate ecosystem stability in extreme oligotrophic conditions. Viral predation may regulate microbial populations, contributing to nutrient remineralization and microbial succession within these ecosystems. These findings underscore the ecological and evolutionary importance of giant DNA viruses in ancient microbial communities. Their structured distribution across microbial mats and stromatolites highlights their role in shaping microbial diversity and influencing metabolic interactions. The combination of high-throughput sequencing, computational taxonomic profiling, and network-based ecological inference provides a robust framework for studying virus-host dynamics in extreme environments, offering insights into microbial resilience and ecosystem evolution.

• Luis Delaye, Departamento de Ingeniería Genética, Cinvestav Irapuato, Irapuato, Guanajuato, 36824, México, México

Cyanobacterial genomes are rich in the motif GCGATCGC, known as the Highly Iterated Palindrome 1 (HIP1). Despite HIP1 being described more than 20 years ago, the function, if any, of this sequence remains a mystery. HIP1 contains the recognition sequence of two DNA methylases (DmtA and DmtC), is conserved along evolution and is found at periodic distances within genomes. However, it is not known if there are proteins, other than the DNA methylases mentioned above, binding specifically to this motif, or if HIP1 correlates with the presence of certain genes. Here we asked whether there are genes whose presence/absence pattern, among cyanobacterial genomes, correlate with the presence/absence pattern of HIP1 and other Highly Iterated Palindromes (HIPs). We found three protein families matching the presence/absence pattern of HIPs and many other proteins that showed statistical evidence of correlated evolution. Among these, we found protein families showing nucleic acid-binding domains and others involved in mismatch repair and natural transformation. We hypothesize that some of these proteins are relevant for the biology of HIP1 and other HIPs found in cyanobacteria.

• Daniel Carrizo

Extreme environments, from the deep ocean to extraterrestrial landscapes like Mars, present unique challenges for detecting and understanding life. Biomarkers, molecular fossils, and stable isotopes serve as powerful tools for studying these environments, providing chemical signatures that reveal past and present biological activity. Lipids biomarkers offer insights into microbial life forms that adapt to extreme conditions, while molecular fossils preserve traces of ancient organisms, even in environments where traditional fossils cannot survive. Stable isotope analysis further enhances our understanding by identifying biological fractionation patterns that distinguish biotic from abiotic processes as well different metabolic pathways involved in the synthesis of these lipid compounds. By integrating biomarker research, molecular fossil analysis, and isotope geochemistry, we can reconstruct past and present biosignatures, offering profound implications about how and under what environmental conditions life arose and evolved on Earth, as well as implications to search for life beyond Earth. In this presentation we are going to talk about our research experience in lipids biomarkers and their isotopic composition and how these tools can help us to infer microbial communities structures, metabolic pathways or paleoenvironmental conditions in different extreme environments on Earth.

• Felipe García-Oliva, UNAM, México
• Atzintli Paniagua-Vargas
• Georgina Ibarra-Arzave
• Bruno Chávez-Vergara.

The freshwater ecosystems of CuatroCienegas (CCC) show bacterial hyperdiversity despite their markedly unbalanced stoichiometry (mainly due to low P concentration). Among these ecosystems, the Pozas Rojas ponds have low P but high S concentrations. The objective of the present study was analyses the structure and nutrients dynamic of the sediments of Pozas Rojas. The water column of the Pozas Rojas ponds shows a high fluctuation between years due to the strong rainfall variability, which produces different sedimentation events over time. Therefore, the sediments are highly stratified, for example, the Poza Roja 1 had 32 distinctly different layers in a 40 cm deep core. Among these layers, some were microbial mats, organic layers or inorganic layers (mainly dominated by gypsum).\nGypsum was the dominant mineral, followed by carbonates. The stoichiometry C:N:P ratio were 174:14:1, 162:26:1 and 423:26:1 for the total nutrients, dissolved organic nutrients and microbial nutrients, respectively. The dissolved organic carbon had a positive correlation with dissolved organic nitrogen (R2=0.42), but the former had a negative correlation with dissolved organic phosphorus (R2= 0.72). Additionally, microbial carbon had a negative correlation with microbial nitrogen (R2=0.66), but microbial carbon and microbial phosphorus had no significant correlation. These results suggest that P is the limiting nutrient for the microbial community, but the microbial community is homeostatic with respect to C and P, suggesting that microbial species have acquisition mechanisms for P uptake and maintenance of P concentration within the microbial biomass. For example, the activity of phosphomonoester enzyme (MPe) was higher than the betaglucosidase enzyme (BGe), therefore the BGe:MPe ratio was 0.96, indicating that the microbial community invests similar energy for P acquisition and C acquisition. \nThe nutrient dynamics among ponds are highly variable. We did a Principal Component Analysis with biogeochemistry variables, the first and second components explain 41 % and 31% of the variance, respectively. C and N in microbial biomass were the variables with the greatest contribution, while microbial phosphorus, dissolved organic phosphorus and N available had the greatest contribution in the second component. The microbial community in ponds with less dissolved organic phosphorus needs to invest more energy in the production of phosphoesterase enzymes than the community in ponds with more dissolved organic phosphorus. All our results suggest that P is the most restricted nutrient in the microbial community of the Pozas Rojas sediments.

• Carlos Arroyo
• Mariano Torres-Gomez
• Mario Guevara, Instituto de Geociencias, UNAM campus Juriquilla, México

Detailed soil information is particularly relevant for enabling large-scale C monitoring systems. The objective is to develop a continuous soil property dataset across the Cuatro Ciénegas Valley (CCV) to support land surface modeling and ecological forecasting. We use ensemble machine learning to predict across 90m grids soil depth and topsoil pH, texture, electrical conductivity, cation exchange capacity, and soil organic C. Our contribution can be used in regional land surface models to account for soils in ecological forecasting.

• Alejandra G. Gutiérrez-Alejandro, UNIVERSIDAD AUTONOMA DE COAHUILA, México
• Jesús Antonio Blanco Moreno, UNIVERSIDAD AUTONOMA DE COAHUILA, Cuba
• Katherline Elena Correa Doria, UNIVERSIDAD AUTONOMA DE COAHUILA, México

In Coahuila, it is common to find outcrops with shallow carbonates alternating with evaporitic sequences (particularly in Cuatro Ciénegas). One of the most representative yet least studied sedimentary sequences is the rocks of the La Virgen Formation, which represent a transition between a marine and/or marginal marine sedimentary basin and the coastline. Although the La Virgen Formation was first described by Humphrey and Díaz in 1956, there are few detailed studies on the types of carbonate environments characterizing these deposits or on the transition between this formation and other geological formations.\nThe most significant findings such as the occurrence and morphology of microbial mats, microfossil assemblages at the La Mula-La Virgen formational transition, and the presence of invertebrate shells are frequent in the Potrero de la Virgen locality and its contact with the Cupido Formation. These suggest that sabkha environments developed more proximally to the Potrero de Menchaca locality, while facies with greater influence from the Cupido Formation’s reefal platform are exposed in Potrero de la Virgen.\nIt is likely that during the Barremian transgression in the La Virgen Formation, there were intermittent desiccation periods alternating with intertidal and supratidal conditions. These conditions allowed the establishment of microbial mats over geologically short intervals. Later, under more stable transgressive conditions or due to the formation of an epicontinental sea, a massive colonization of the substrate may have occurred in the limestones of the upper contact with the Cupido Formation at Potrero de Menchaca.\nThe presence of Thaumatoporella parvovesiculifera (RAINERI) and Charentia sp. is reported here for the first time in the La Virgen Formation. In contrast, Choffatella decipiens was previously reported by Wilson and Piali in 1977. However, the occurrence of Choffatella decipiens in the La Virgen Formation also constitutes a first-time report. The carbonate facies, dominated by grainstone microfacies composed of bioclast assemblages (bivalves, foraminifera, and echinoderm spines), altered ooids (recrystallization or micritization), indicate environmental conditions with a relatively higher energy regime. Such microfacies are associated with less restricted areas, such as tidal flats, where evaporation and marginal desiccation occurred between the coast and the sediment-water interface, fostering the observed microbial mat morphologies. These environmental conditions likely formed on a homoclinal gentle ramp, as suggested by the observed facies changes.\nPreserved sedimentary structures such as lamination, evaporite pseudomorphs, fenestral textures, and desiccation cracks in the evaporitic facies also indicate supratidal conditions. Furthermore, other structures, including desiccation features and the presence of Ophiomorpha sp. and particularly Thalassinoides sp., suggest not only a shallower environment but also a more continental setting.\n

• Martha Adriana Martínez-Olivas, Universidad Autónoma de Nuevo León, México
• Silverio Alejandro Melchor-Rangel
• Miguel Ángel Mendoza-Cibrian
• Paola Benavides-García
• Susana De la Torre-Zavala

Actinomycetes, especially Streptomyces, have been considered one of the main sources of secondary metabolites, essentially for use as antimicrobials, immunosuppressants and anticancer agents. Advances in sequencing and computational tools have shifted research on new molecules toward the study of biosynthetic gene clusters (BGCs), creating\nbiosynthetic novelty standards [1] that have not yet considered that artificial intelligence provides better prediction tools. Furthermore, failure to meet these standards may result in the discarding of genomic information, potentially overlooking hidden molecules within bacterial DNA, such as those synthesized by RiPPs, a more complex BGC class\nwith significant potential [2], with special emphasis in rare organisms such as those found in extreme environments like Cuatro Ciénegas pools [3, 4]. Objective: This study aimed to determine if a thermotolerant Streptomyces novel strain harbors RiPPs with capacity of blood brain barrier (B3) penetration. Methods. Samples were collected in\nCuatro Ciénegas Basin from a karstic environment called Pozas Becerras. Selective isolation was performed using ISP7 solid medium (27º C, 3 weeks), strain was selected by morphology and characterized by gram staining and microscopy. The optimal growth temperature range was also determined using ISP2. gDNA was extracted using a modified phenol/chloroform method [4] and sequenced by Novogen (UC Davis, San Diego, Ca. USA) using Illumina NovaSeq 6000 x 150 at 100x depth. Downstream analyzes were done using Google colaboratory and Galaxy server for preprocessing (Fastqc and fastp), assembly (SPAdes) and annotation (Prokka). Phylogenomic analyzes were done using TYGS and VBCG pipelines alongside ANI calculations (KBase). BGCs predictions were performed using AntiSMASH and DeepBGC, RiPPs from these tools were introduced to AUGUR and SCMB3PP pipelines to seek a\nconsensus for blood brain barrier penetration predictions. The aminoacidic profile of the predicted RiPPs was obtained using GENOMEspot and correlated to the predictions using the R environment. Results. A thermotolerant actino-\nmycete (45º C) was isolated from Poza la Becerra. Phylogenomic analyses support its classification as a putatively novel species. Using Antismash and DeepBGC, 31 and 152 BGCs were identified, respectively, from which a total pool of 13 RiPPs were obtained. Of the 13 RiPPs evaluated, 12 were classified as potential Blood-Brain Barrier Penetrating Peptides (B3PP) by Augur, and only 10 by SCM3PP. High consensus scores between tools identified 4 potential RiPPs with the ability to cross the blood-brain barrier, 1 of which was predicted by both Antismash and DeepBGC at the same node. Positive results were also associated with a moderate Arginine content. Conclusions. A novel extremotolerant Streptomyces sp. was isolated. The BGCs prediction reveals new possible biosynthetic pathways. Morevover, consensus prediction between AUGUR and SCMB3PP showed RiPPs that potentially cross B3, expanding the known\nbiosynthetic repertoire of extremotolerant actinomycetes and challenge conventional genome mining strategies. By leveraging AI-driven predictions, we demonstrate that novel computational approaches can uncover pharmacologically relevant molecules in genomes that might otherwise be deprioritized in traditional biodiscovery pipelines.

• Antonio González-Sánchez, Cinvestav, México
• Luis Lozano-Aguirre, CCG-UNAM, México
• Guadalupe Jiménez-Flores, ISSSTE, México
• Mariana López-Sámano, ENES-UNAM, México
• Alejandro García-de Los Santos Miguel A. Cevallos, CCG-UNAM, México
• Miguel Ángel Cevallos, CCG-UNAM, México
• Sylvie Le Borgne, Metropolitan Autonomous University, México

The Naica mine, located in Chihuahua, Mexico, is globally renowned for its extraordinary geological formations, including the Cave of Crystals, which contains the world’s largest gypsum crystals. Despite the mine’s geological significance, microbiological studies on this extreme environment are scarce. This study explores the genomic and physiological characteristics of two Cupriavidus gilardii strains, NOV2-1 and OV2-1, isolated from iron oxide crusts in Naica’s hot and heavy metal-rich tunnels at -290 m. The Naica mine provides a unique environment characterized by high temperatures (45-55°C), high humidity, and elevated concentrations of heavy metals, making it an ideal environment for studying microbial adaptations to extreme conditions.\nGenome sequencing of NOV2-1 and OV2-1 revealed that both strains are closely related to the C. gilardii genus, with an average nucleotide identity (ANI) of over 98% when compared to C. gilardii CCUG 38401T. The genomes of NOV2-1 and OV2-1 consisted in two replicons: a chromosome of 3.58 and 3.53 Mb, respectively, and a chromide of 2.1 Mb in both strains, a common feature in Cupriavidus species. Discrete differences were observed between C. gilardii CCUG38401T, NOV2-1, and OV2-1 in the biochemical tests. NOV2-1 and OV2-1 exhibit a strong tolerance to zinc, lead, copper, cadmium, nickel and cobalt. This tolerance is associated with the presence of conserved heavy metal resistance (HMR) gene clusters, which are thought to be involved in metal ions detoxification and efflux. NOV2-1, in particular, displayed a higher tolerance to heavy metals compared to OV2-1. Both strains demonstrated an ability to grow at temperatures up to 48°C, suggesting that C. gilardii strains from the Naica mine are adapted to thermophilic environments. This is consistent with the thermal conditions of the mine, where temperatures range between 45-55°C. Interestingly, the strains were unable to assimilate several common carbon sources, a metabolic characteristic observed in other Cupriavidus species, which may contribute to their role in detoxifying environmental pollutants by metabolizing complex compounds rather than simple carbohydrates.\nMoreover, the presence of mobile genetic elements at the vicinity of the HMR clusters detected in NOV2-1 and OV2-1 indicates the potential for horizontal gene transfer, facilitating the spread of such adaptive traits. This study emphasizes the importance of understanding the genetic and physiological mechanisms that allow C. gilardii to thrive in extreme environments and highlights its potential for bioremediation, particularly in environments contaminated with heavy metals at high temperatures. The findings also suggest that C. gilardii could be harnessed for biotechnological applications in environmental cleanup and heavy metals waste management. These strains provide valuable insights into microbial adaptability and the potential for using extremophiles in biotechnological and industrial applications.

• Karen Lloyd

Many natural springs flush deep subsurface microbes up to the surface. This allows us to obtain a landscape scale view of the subsurface biosphere and determine how it might be supported by deep volcanic volatile emissions. These deep volatiles include carbon, hydrogen, sulfur and nitrogen compounds that can serve as biomass and energy resources for a deep subsurface biosphere. I will present recent research establishing these relationships across the Costa Rican subduction zone.

• Mariano Cerca, Instituto de Geociencias, Universidad Nacional Autónoma de México, Blvd. Juriquilla, 3001, 76230, J, México
• Barbara Moguel
• Janeth Sánchez-Sánchez
• Dora Carreón-Freyre
• Rocío J. Alcántara-Hernández
• Yesenia Villegas-Zuppa

In recent years, advances in geomicrobiology and genomics have transformed our understanding of microbial interactions with the geosphere, shedding light on Earth's history and environmental sustainability. The integration of geological investigations with genomic technologies allow us to unravel the complexities of microbial ecosystems and explore the limits of life in extreme environments that can be extrapolated to ecosystems impacted by climate change. Microbial processes have left a lasting imprint on Earth's geological record, influencing mineral formation, sedimentary structures, and elemental cycling over billions of years. \nThe volcanic lakes in the Trans-Mexican Volcanic Belt (TMVB) constitute natural laboratories for studying microbial processes in dynamic geological settings through the study of sedimentary sequences that contain clay minerals and other alteration products of volcanic ashes. Additionally, in certain areas, hydrothermal groundwater input through faults and fractures has been observed, supplying nutrients that sustain microbial communities. These sediments host extremophilic microorganisms—including halophiles, thermophiles, and alkaliphiles—which occur as semi-fossilized microbialites or as active communities thriving under high salinity, alkalinity, and temperature conditions. Moreover, during the past four decades, excessive groundwater extraction has led to desiccation and significant deformation due to subsidence in many lacustrine areas of central Mexico. \nThis study presents initial results from an ongoing project aimed at understanding the relationship between water flow and the formation of clay minerals linked to microbial processes in the volcanic valleys. Sediment samples have been collected from the craters of Rincón de Parangueo (RP) and La Alberca (LA), with additional sampling planned for Texcoco, Cuitzeo, and Pátzcuaro lakes. In RP and LA, minerals such as aragonite and hydromagnesite are linked to microbial carbon fixation under alkaline and hypersaline conditions. Hydromagnesite has also been found in microbial mats in RP, where biofilms act as nucleation sites for calcium carbonate precipitation under fluctuating salinity conditions. Microbial activity is closely associated with the formation of montmorillonite, a smectite-group clay mineral, in these volcanic environments. Clay minerals form through the weathering and hydrothermal alteration of volcanic ash, with microbial communities influencing its transformation by modifying pH, redox conditions, and ionic composition. In highly alkaline and hydrothermal environments, microbes regulate the precipitation and stability of montmorillonite by mediating silica and alumina availability. Certain bacteria and archaea can further facilitate its formation through enzymatic processes and biofilm interactions, which promote mineral nucleation and growth. These microbial influences have broader implications for understanding soil and sediment development, hydrothermal systems, and the long-term stabilization of volcanic terrains. \nThe broader goal of this interdisciplinary project, UNAM PAPIIT-IG101325, is to identify the conditions under which clay materials form in lacustrine environments and to analyze the development of physical properties in the sediments that fill volcanic valleys in central Mexico. By assessing the physical, chemical, and biological characteristics of clay-rich soils—particularly their moisture retention capacity, biological activity, and deformability—this study will help evaluate their ecological significance, agricultural potential, and suitability for future urban infrastructure development.

• Barbara Moguel, Universidad de las Americas Puebla, México
• Mariano Cerca
• Janet Sánchez-Sánchez
• Israel Múñoz
• Marina Vega
• Gabriela Olmedo-Alvarez

Maar lakes, shaped by volcanic activity and extreme physicochemical conditions (high salinity, alkalinity, UV exposure, and desiccation), provide unique ecosystems to study microbial interactions and its ecological roles. This research characterizes Eukarya communities in the hypersaline, alkaline maar lake Rincón de Parangueo (RP), Mexico, using 18S rRNA gene metabarcoding to explore their taxonomic diversity, ecological roles, and stress adaptations across four microhabitats: microbialites, sediments, microbial mats, and water bodies. Environmental DNA (eDNA) analysis of 13 samples revealed distinct eukaryotic assemblages in each microhabitat, with no single taxonomic family shared across all four ecosystems, highlighting niche-specific adaptations. Chlorophyta emerged as the most abundant phylum, particularly dominating microbialites (47.2%) and microbial mats (33.8%), where green algae like Dunaliella exhibited adaptations to hypersaline stress through osmoregulation and carotenoid production. Diatoms (Bacillariophyta), ciliates (Ciliophora), heterotrophic protists, and fungi found in the analysis, may have critical roles in nutrient cycling, organic matter decomposition, and microbialite formation by modulating pH and carbonate precipitation. Microbialite samples, traditionally considered prokaryote-dominated structures, showed significant eukaryotic contributions, with phototrophic microeukaryotes influencing mineral deposition and organic matrix synthesis. Stress tolerance mechanisms are widespread among identified taxa: 1) Osmotic regulation in Chlorophyta via glycerol accumulation, 2) Exopolysaccharide production by diatoms and fungi to mitigate desiccation, and 3) Metabolic flexibility in ciliates, enabling survival under fluctuating oxygen levels. The water bodies, gradually desiccating, harbored the least diverse communities, underscoring their vulnerability to environmental change. Comparative analyses with other extreme ecosystems revealed RP´s unique taxonomic profile, driven by volcanic and evaporative processes. The high diversity of Eukarya found in RP and its capacity to live and proliferate in this extreme environment. This study challenges the paradigm of prokaryote dominance in extreme environments, demonstrating the active presence of microeukaryotes. They contribute to biogeochemical cycles through silicate weathering (diatoms) and sulfate reduction (fungi), enhance ecosystem resilience via stress-tolerant biofilm formation, and influence microbialite morphogenesis through prokaryote-eukaryote interactions. The findings emphasize RP´s value as a model system for studying evolutionary adaptation, with implications for astrobiology and conservation. As groundwater extraction accelerates RP´s desiccation, this research provides urgent baseline data for preserving its unique biodiversity. By integrating high-throughput sequencing with geochemical analyses, this work advances our understanding of eukaryotic ecology in extreme environments and redefines their role in shaping Earth´s most inhospitable ecosystems. ACKNOWLEDGE MENTS We thank Sara Solís Valdez, Ricardo J. Carrizosa Elizondo, María Carolina Muñoz Torres and Vania Ferrer for help on the soil and water analysis, and Luis Aguilar, Alejandro de León, Carlos S. Flores and Jair Santiago Garcia Sotelo of the Laboratorio Nacional de Visualización Científica Avanzada (UNAM) for assistance in the bioinformatic analysis. To the PAPIIT IG101325 for funding this project.

• Ana Gutiérrez-Preciado, DEEM, ESE, Universite Paris Saclay, France
• Bledina Dede
• David Moreira
• Purificación López-García

In the North Danakil depression, Ethiopia, lies the geothermal system of Dallol. The hyperacidic, hypersaline brines of the Dallol protovolcano appear devoid of life due to their particular hydrochemistry, combining low water activity, chaotropic salts, and other chemical extremes. However, at the base and surroundings of the Dallol dome, some of these harsh conditions begin to ease, allowing a limited number of microbial phyla to colonize these marginal niches. These brines exhibit salinities ranging from 30% to ca. 45%, a mildly acidic pH, and high chaotropicity. In this study, we analyzed metagenomes and metagenome-assembled genomes (MAGs) from geothermal hypersaline environments in the Danakil Depression, where chaotropicity increases alongside salinity. Using normalized abundances of universal single-copy genes, we found that haloarchaea and Nanohaloarchaeota make up 99% of microbial communities in the extreme conditions of the Western-Canyon Lakes. Microbial lineages known to survive in salt-saturated environments rely on a 'salt-in' strategy, accumulating high intracellular K+ concentrations to maintain osmotic balance, and their proteins are characteristically enriched in acidic amino acids. Comparative analyses with proteomes from freshwater, seawater, and hypersaline salterns (6-14-32% salinity) revealed that Danakil archaea encode the most acidic proteomes observed to date (median isoelectric points <4.4). We identified previously undescribed haloarchaeal families as well as an Aenigmatarchaeota family and a bacterial phylum independently adapted to extreme halophily. Although overall phylum-level diversity decreases with rising salinity and chaotropicity, archaea in the Danakil ecosystems display a notable diversification not seen in solar salterns. This suggests that local hydrothermal activity and metabolic flexibility, particularly the ability to use multiple carbon and energy sources under fluctuating conditions, shape microbial communities in these ecosystems near life limits.

• Joel Stavans

Large groups of agents often exhibit self-organized, collective motion and the emergence of coherent spatial structures whose characteristic scales largely exceed the size of the agents themselves. Prime examples covering many length scales range from mammal herds, fish schools and bird flocks, to insect and robot swarms. Despite significant advances in understanding the behavior of large homogeneous groups in the last decades, little is known about the self-organization and dynamics of heterogeneous groups.

Under oxygen gradients, oxytactic (aerotactic) motile bacteria can swim in auto-organized, flows called bioconvection, whose spatial scales exceed the bacterial size by three orders of magnitude. I will present results of bioconvection experiments with multispecies suspensions of wild-type bacteria collected from the hyper-diverse bacterial communities of Cuatro Ciénegas in Mexico, whose origin date to the pre-Cambrian. Our real time fluorescence microscopy experiments show that these bacteria display a plethora of amazing dynamical behaviors, including inter-species spatial segregation in shallow suspensions. The mechanisms giving rise to these complex behaviors stem both from biological and physical inter-species interactions.

The results advance our understanding of heterogeneity in the dynamics of complex planktonic microbial ecological communities and the role of oxygen in the water column, bringing profound insights into their spatial organization and collective behavior.

• Beatriz Baselga Cervera, University of Minnesota, United States
• Nahui Olin Medina-Chávez
• Paloma Martínez-Alesón García
• Beatriz Baselga Cervera

Cyanobacteria blooms present remarkable physiological, biochemical, and genetic heterogeneity. Much research has aimed at understanding cyanobacteria blooms, their impacts on the ecosystem, and potential public health issues. As dynamic microbial communities, cyanobacteria blooms are determined by biotic and abiotic interactions, affecting the toxicity, species and strain composition, and population dynamics. However, temporal and functional interactions between cyanobacteria and co-occurring bacteria are underexplored. To address this knowledge gap, we carried out a synthetic microbial communities (SynCom) experiment in laboratory conditions. Microcystin-LR-producing and non-producing unicellular cyanobacteria xenic environmental isolates were investigated independently and in combination. Through the propagation of replicate communities, we studied the population dynamics of the cultivable associated bacteria, cyanobacteria species growth, and microcystin-LR production. Cyanobacteria and associated bacteria were identified via sequencing, and the communities’ composition was determined through metagenomics. Cyanobacteria strains were identified as a Microcystin-LR-producing Microcystis sp. and a Synechococcus sp. Experimental results suggest a succession of cyanobacteria strains in the combined experimental group in which Microcystis sp. is displaced by Synechococcus sp. Associated bacteria dynamics fluctuated throughout the experiment, but the community composition was stable within experimental groups. Associated bacteria identified are aerobic and predominantly nitrogen-fixing or anoxygenic phototrophic bacteria. Toxicity assays suggest that some associated bacteria growth is affected by microcystin-LR. These results enable us to assess community-intrinsic properties and evaluate temporal and functional SynCom dynamics.

• Gerardo Ruiz-Amores
• Manuel A. Barrios-Izás
• Norberto García-Miranda
• Iván Anguiano
• Alejandra Rodríguez-Verdugo
• Adam Olshen
• Maribel Hernández-Rosales
• Gabriela Olmedo Alvarez, Cinvestav, México

Our research on antibiotic resistance takes a unique approach, revealing how community competitive interactions have influenced microbial evolution. We leverage the ecological dynamics of bacterial isolates from microbial communities of Cuatrociénegas, Coahuila, a pristine site in Mexico, to offer new insights into the applied aspects of the One Health concept. Unlike most studies that focus on a narrow taxonomic window of human pathogens shaped by antibiotic selection, we step outside the clinical framework to explore the origins of antibiotic synthesis and selection processes in microbes. Our research investigates antibiotic resistance through the lens of microbial community interactions, shedding light on how competitive dynamics shape microbial evolution. \nWe analyzed 78 bacterial isolates to identify competitive traits that drive the evolution of antibiotic synthesis and resistance. Genomic analyses using the Comprehensive Antibiotic Resistance Database (CARD) revealed primary resistance mechanisms such as efflux pumps, antibiotic inactivation, and target alterations, with all eleven examined taxa containing strains classified as Multi-Drug Resistant (MDR). Phenotypic assessments confirmed resistance to multiple antibiotic classes, reinforcing the genomic findings.\nOur study also uncovered substantial diversity in β-lactamase genes within the Bacillaceae, including variation in gene classes and copy numbers. Presence and copy number of β-lactamase genes corresponded closely with the resistance phenotype observed against β-lactam antibiotics. We also demonstrated β-lactamase activity both through protective interactions with carbenicillin-sensitive strains and nitrocefin assays. Notably, Class A and D β-lactamase genes were broadly distributed across clades, while metallo-β-lactamase genes (Class B) were exclusive to B. cereus. Gene copy number Unexpectedly, β-lactamase activity was unaffected by clavulanic acid, and some strains exhibited increased enzyme synthesis upon exposure to EDTA. Horizontal gene transfer of β-lactamase genes appeared constrained, except for one instance involving a non-Bacillaceae gene.\nOur findings highlight significant phenotypic and genotypic associations between antibiotic resistance and antibiotic resistance genes (ARGs), emphasizing community dynamics. Strains resistant to antagonistic interactions exhibited the broadest ARG repertoires, validated by phenotypic analyses. By focusing on natural microbial interactions, this research provides a deeper understanding of antibiotic resistance evolution, presenting valuable perspectives for addressing this global health challenge.\nPhenotypic and genotypic associations between antibiotic resistance and ARGs highlight the community dynamics. The strains known to be resistant to antagonism from members of the community possessed the most extensive repertoire of antibiotic resistance genes, confirmed by phenotypic analysis. By retelling the story of antibiotic resistance from the competitive interactions within microbial communities, we emphasize the pivotal role of microbial interactions in natural communities in shaping ARGs content. This perspective offers a deeper understanding of antibiotic resistance evolution and provides valuable insights for combatting this global health challenge.\n

• Carolina Sánchez-López, Cinvestav, México
• Yanahi Posadas, Cinvestav, Mexico
• Victor E. López-Guerrero, Cinvestav, Mexico
• Liliana Quintanar, Cinvestav, Mexico

The study of transition metals in biological systems has generally focused on their participation as cofactors of enzymes with essential functions such as electron transfer, transport, and/or oxygen activation. However, transition metals are also involved in cell signaling processes and modulation of critical cellular responses. Copper is one of the essential and most abundant metals in eukaryotic organisms. Its ability to adopt two oxidation states under physiological conditions—the reduced form as Cu(I) and its oxidized form as Cu(II)—makes it a participant in many physiological processes. Furthermore, copper has been implicated in protein amyloid aggregation processes associated with degenerative diseases. Neurodegenerative diseases such as Alzheimer's, Parkinson's, and prion diseases, and degenerative diseases such as type 2 diabetes and cataracts, have been widely studied because they form these types of protein aggregates. Furthermore, the homeostatic imbalance of transition metals, including copper, has been associated with the pathogenesis of these diseases.
Thus, the study of copper coordination with these proteins is important as it lays the foundation for understanding the role that copper-protein interactions play in protein function and/or in the amyloid aggregation mechanism associated with these proteins. In our work, we have performed a detailed spectroscopy study of Cu(II) binding to peptides, proteins, and hormones, using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), electronic absorption and circular dichroism in the UV-Vis region and X-ray absorption.

• João Carlos Setubal, University of São Paulo, Brazil

We have developed a computational tool that can mine large-scale metagenomic datasets for their species and strain diversity given user-specified bacterial genera. In our tests, this tool provides more accurate results than general-purpose taxonomic classification programs. In this talk I will describe the tool and show results for a few genera, such as Xanthomonas, Acinetobacter, and Stutzerimonas.

• Beatriz Carely Luna Olivera, SECIHTI-UPN 201 Oaxaca, México
• Eduardo Sánchez Soto , UTM, México
• Rosa Elena Aguilar Galindo, SECIHTI-CIIDIR Oaxaca, México
• Marcelino Ramírez Ibáñez, SECIHTI-UPN 201 Oaxaca, México
• Mario César Lavariega, CIIDIR Oaxaca, México

In this talk, we will discuss mathematical objects known as graphs or networks, which consist of vertices and edges, and how these objects can be useful in representing different types of interactions in ecological systems. Two cases will be presented: one involving bacteria and the other involving mammals, both in protected areas.

• José Antonio Ramírez-Rafael Annachiara Korchmaros
• Katia Aviña-Padilla
• Alitzel López-Sánchez
• Gabriel Martinez-Medina
• Alfredo J. Hernández-Álvarez
• Marc Hellmuth
• Peter F. Stadler
• Maribel Hernández-Rosales, Cinvestav Irapuato, México

Understanding the evolutionary history of gene families is central to comparative genomics, phylogenetics, and functional annotation. We present REvolutionH-tl, a robust, end-to-end software platform for the scalable inference of orthology, gene trees, species trees, and reconciliation maps directly from sequence data. REvolutionH-tl introduces a unified pipeline that integrates theoretical advances in graph-based orthology inference, particularly the formalism of best match graphs (BMGs), with practical innovations in algorithmic efficiency and interpretability.\nREvolutionH-tl begins with alignment-based identification of best hits using DIAMOND or BLAST. From these, it estimates BMGs whose connected components define orthogroups. Gene trees are inferred from these graphs using informative triples and the BUILD algorithm, followed by event-labeling (speciation or duplication) via species overlap analysis. Polytomies at duplication nodes are resolved using a modified neighbor-joining strategy, while species trees are reconstructed from gene trees through heuristically extended Aho graph methods. Reconciliation is performed by mapping gene tree nodes to the species tree to infer evolutionary events, including duplications and losses. The tool further includes reconciliation-aware corrections of inconsistent gene trees to improve biological realism.\nA central innovation of REvolutionH-tl is its seamless integration of publication-quality visualizations, including embedded reconciled gene trees and summary diagrams of orthogroup statistics and gene content evolution. This makes complex evolutionary histories accessible to users beyond computational specialists, a significant advance over other tools that require external post-processing for visualization.\nWe benchmarked REvolutionH-tl against state-of-the-art tools, such as Proteinortho, OrthoFinder, RAxML, GeneRax, ASTRAL-Pro, RANGER-DTL, on both synthetic (SaGePhy) and empirical datasets (Phylome05 metazoan genomes). REvolutionH-tl consistently achieves superior or comparable accuracy in orthology prediction, gene and species tree reconstruction, and reconciliation, while maintaining significantly lower computational time. In particular, it nearly perfectly recovers orthogroups, maintains low false positive rates for gene tree triples, and exhibits the smallest reconciliation distance from ground-truth evolutionary scenarios.\nUnlike traditional pipelines that rely on external phylogenetic tools and models, REvolutionH-tl provides a self-contained, model-free alternative grounded in graph theory and maximum parsimony principles. Its reconciliation-aware inference, visual interpretability, and cross-platform implementation make it particularly suitable for large-scale studies of gene family evolution across both microbial and eukaryotic clades.\nREvolutionH-tl is open-source and freely available at https://pypi.org/project/revolutionhtl/. Its comprehensive approach sets a new standard for evolutionary analysis by enabling fast, accurate, and biologically interpretable reconstructions from genomic data.\n

• Elizabeth Chacón Baca

Through the fossil record organosedimentary rocks known as microbialites have been continuously forming mainly as microbial carbonates. Such microbial carbonates result from multiple microbial-mineral interactions among a great diversity of microbial communities and under a wide range of environmental conditions. Not only microbialites are the oldest paleontological evidence of life on Earth but also a rich source of biosignatures with the greatest potential preservation potential on extraterrestrial surfaces. This talk includes relevant aspects on the microscopical characterization of the thrombolites from Cuatro Cienegas as modern analogues where geobiological processes act at different scales

• Dora Carreón Freyre, Instituto de Geociencias, UNAM, México
• Mariano Cerca, Instituto de Geociencias, UNAM, México

The Cuatro Ciénegas Valley in Coahuila, Mexico, is an endorheic basin with a drainage network that infiltrates through permeable alluvial deposits filling the valley and discharges into approximately 200 water bodies, including 165 pools ('pozas'). These pools are springs that emerge from discontinuities in limestone rocks, with dimensions ranging from 3 to 25 meters in length and depths exceeding 5 meters in only two cases. The drainage flow is predominantly west to east, with most pools located at the base of the San Marcos and Pinos mountain range, while others are found near the La Madera, La Purísima, and San Vicente ranges.The Cuatro Ciénegas aquifer maintains hydrogeological connections with adjacent aquifers, including Cuatro Ciénegas-Ocampo to the north and El Hundido and Valle de San Marcos to the south. Geochemical and isotopic studies have documented the coexistence of intermediate and regional groundwater flows, as well as local flows responsible for the formation of springs and pools. This shallow, unconfined aquifer is primarily recharged by rainwater percolating through the limestone formations of the San Marcos mountain range. However, isotopic analyses indicate a mixture of local and regional flows. The high solubility of limestone has led to the formation of underground cavities and flow channels, while the region’s fault system enhances hydraulic connectivity between different water flows and allows the intrusion of hydrothermal fluids with high ionic concentrations and elevated temperatures.The springs with the highest discharge—Churince, Becerra, Azul, and Escobedo—exhibit characteristics of intermediate flows, with high sulfate (gypsum) concentrations. Poza Escobedo, Poza Azul, and Poza Mojarral maintain temperatures above 30°C throughout the year, while others (Churince, Mojarral, and Bonita) vary between 21°C and 27°C.The flow rate of local recharge varies seasonally and annually in response to precipitation, maintaining a water table between 3 and 5 meters deep. However, this system is highly sensitive to water level declines and contamination. Records indicate that the primary cause of piezometric level depletion in the region is excessive well pumping for irrigation in adjacent agricultural fields, as well as water transfers through canals. The interconnection between local and regional flows is evident, as groundwater depletion directly impacts the shallow levels of pools and springs, putting the ecosystem at risk.Given this vulnerability, it is crucial to develop a regional hydrogeological model that integrates all interconnected aquifers within the Cuatro Ciénegas system. This model will be essential for evaluating conservation and restoration strategies for these unique aquatic ecosystems within the Chihuahuan Desert.

• Otoniel Carranza-Diaz, SICA MEDICION, México
• José Valdemar López-Morales

The water bodies of Cuatrociénegas consist of springs, ponds, pools, lakes and rivers which are home to microscopic organisms of great ecological importance. In addition, aquatic organisms like the Cuatrociénegas tilapia and Terrapene coahuila live in this ecosystem. Water quality plays an important role in the conservation of these species. For thousands of years, they have adapted to the specific conditions of salinity, temperature, and pH. However, in recent times, population growth and agricultural development have led to drops in the water table levels of the basins and environmental contamination. To develop strategies to mitigate anthropogenic activities in the Cuatrociénegas water bodies, monitoring is essential. Various on-line and laboratory equipment can be used for this purpose. For example, toxicity monitoring can be carried out online using the TOX ALARM analyzer from Process Insights. This analyzer uses nitrifying bacteria to assess toxicity in water samples. In fragile aquatic environments, this analyzer can be used to measure toxicity at specific sites where contamination from punctual and non-punctual sources is possible. Toxicity is a parameter recently introduced in Mexican legislation (NOM-001-SEMARNAT-2021). But this parameter also determines the health of an aquatic ecosystem. Monitoring toxicity can also be carried out with Aquacience's Biolight equipment, which uses the Vibrio fisheri bacteria for toxicity analysis. SICA MEDICION offers a wide range of water analysis equipment, whether for online or laboratory measurements, water quality can be measured accurately and reliably. SICA MEDICION represents more than 50 brands of analyzers with several applications in matrices such as water, soil, and air (gases).

• Mariano Torres-Gómez, Geosciences Institute UNAM, México
• Dora Carreón-Freyre
• Sara Solís
• Alberto Prado
• Carlos Arroyo
• Arely Rosas
• Luis Felipe Castelblanco
• Mario Guevara

La Joya-La Barreta Ecological Park is of great ecological importance as it hosts native flora species of Querétaro's semi-desert, serves as a habitat for diverse fauna species, and is a key ecosystem for C sequestration and storage, influenced by edaphic, topographic, and climatic factors. This study estimated stocks of soil organic C (SOC) and vegetation organic C (VOC), as well as basal respiration as an indicator of microbial activity, providing an essential baseline for the sustainable management of the park and decision-making in the context of greenhouse gas mitigation. We compare these stocks on a yearly basis (2023-2024). VOC varied from 8.6 to 15.5 Ton C ha⁻¹ across years. SOC variation across years was not significant, around 130 and 140 Ton C ha⁻¹. Our results suggest that VOC stocks in the park for the analyzed years may vary from 2107 to 3797.5 Ton C. In contrast, SOC stocks are larger, and they may vary from 31850 to 34300 Ton C. These results will allow to develop digital C mapping frameworks to refine estimates on each corner of the park.

• Laxmi Parida, IBM Research, United States

AI, particularly Foundation models and Generative AI, has many success stories in a wide arena of applications, including biology. Does AI solve it all? I will discuss some problems that are not very suitable for AI. I will give a quick introduction to topological data analysis (TDA) and describe the application of TDA to these problems. In the final part of the talk I will discuss an exploration we are currently doing with the emerging technology of Quantum Computing.

• Luis David Alcaraz

An abstract will be loaded shortly for this presentation by the presenter

• balabhaskar Kalaparapu, TBMICS, India
• balabhaskar Kalaparapu, KL University, India

Abstract\n\nVitamins and proteins play a vital role in human health, but their deficiency or overdose can contribute to disease development. This study focuses on leveraging computational biology and deep learning techniques to analyze how human genes respond to vitamin imbalances, aiming to prevent disease through optimal nutrient intake. Using PyTorch for deep learning and BioPython for genomic analysis, we employ adversarial attack models to simulate gene perturbations under varying vitamin levels. Open-source biological datasets from OpenBio.org enable large-scale analysis of disease-causing genetic patterns linked to vitamin misuse. By identifying critical genetic markers affected by excessive or insufficient vitamin intake, this research provides insights for developing affordable healthcare solutions. The findings contribute to personalized nutrition strategies, disease prevention, and cost-effective public health policies. This study bridges computational biology with real-world applications, ensuring that accessible, data-driven solutions guide vitamin usage for better health outcomes and disease prevention.\n\nThe integration of adversarial attack models in computational biology provides a novel approach to stress-test genetic stability under vitamin-induced variations. By introducing controlled perturbations in gene expression datasets, we assess the resilience of disease-associated genes to fluctuations in vitamin intake. This methodology enables the identification of key genetic vulnerabilities, allowing researchers to refine existing models for predicting disease risks associated with overconsumption or deficiency. The use of PyTorch and BioPython facilitates efficient processing of large genomic datasets, ensuring that the analysis remains scalable and adaptable for future research.\n\nBeyond scientific research, the findings have practical implications for public health and preventive medicine. The ability to predict disease risks based on vitamin levels allows for the development of targeted nutritional interventions that are both cost-effective and accessible to the general population. This approach aligns with the goal of affordable healthcare, where computational insights drive informed decision-making in clinical nutrition. By making use of open biological resources, this study democratizes access to genomic research, empowering healthcare professionals and policymakers to implement strategies that minimize the risks associated with improper vitamin consumption.

• García-González Octavio Patricio, Instituto Traslacional de Singularidad Genómica, México
• Meléndez-Cardiel Michelle Alejandra Villa-Pérez José Saúl
• Guzmán-Molina Mónica
• Sánchez-Sánchez Rocio
• Piña-Torres Iván Horacio
• Díaz-Sánchez Mauricio

PABLO is an adaptive AI-based platform that integrates epidemiological surveillance, outbreak forecasting, and qPCR assay design. Originally developed for public health, its modular design allows applications in microbial ecology, environmental genomics, and bioprospecting. By combining machine learning, natural language processing, and bioinformatics pipelines, PABLO enables automated detection of biological trends and in silico design of molecular assays targeting pathogens and functional microbial genes across diverse ecosystems.

• Mike Travisano
• Valeria Souza, UNAM

I will present insights from experimental evolution studies that explore how simple microbial systems evolve complexity. Our research reveals how ecological interactions and selection pressures shape the emergence of multicellularity. By studying microbial communities over thousands of generations, my research group offers a window into the mechanisms driving biological innovation.

• Natalia Said Muñoz
• Carina Uribe Díaz
• Sur Herrera Paredes, Universidad Nacional Autónoma de México, México

Rising global temperatures are reshaping microbial ecosystems, including in the rhizosphere, where plant-associated bacterial communities play a key role in nutrient cycling and plant health. While both abiotic and biotic factors drive microbial community dynamics, their combined effects remain insufficiently explored. Here, we present a strategy to efficiently explore microbial community space using synthetic bacterial communities. We designed twelve five-strain synthetic communities from rhizosphere bacteria and subjected them to two temperature regimes (28°C and 32°C) over three days. Growth and community composition were monitored using absorbance, metabarcoding, and absolute quantification via qPCR, allowing us to disentangle the effects of temperature and species interactions on bacterial abundances and community structure.\n\nOur results reveal that while temperature has a limited effect on overall strain abundances, it significantly alters the growth dynamics of specific communities. Community composition plays a dominant role, with strain substitutions leading to major shifts in community composition, while the effect of temperature was dependent on community context. Comparisons with single-strain dynamics suggest that competition is the primary mode of biotic interaction. Additionally, we identify species interactions directly from community dynamics, which may shape emergent community patterns. This study highlights the power of synthetic communities as a scalable tool to efficiently map microbial community space and elucidate the interplay between biotic and abiotic factors in shaping microbial ecosystems, particularly in the context of ongoing climate change.

• Etzel Garrido, Universidad Autónoma de Querétaro, México
• Zyanya Mayoral-Peña, Universidad Autónoma de Querétaro, México
• Ana Moran-Orozco, Universidad Autónoma de Querétaro, México
• Carmen Anistro-Romero, Universidad Autónoma de Querétaro, México
• Roberto Álvarez-Martínez, Universidad Autónoma de Querétaro, México

Plants and their herbivorous insects have been interacting for over 400 million within a microbial milieu that shapes their ecology and evolution. Over the past decade, our understanding of how microorganisms shape plant-insect interactions has advanced rapidly. However, the extent to which plant-associated microbes affect insect performance and how insect-associated microbes influence plant defences, remains largely unexplored. While eating, all the microbes associated with the leaves are also inevitably consumed by the larvae. Thus, the phyllosphere might represent the first line of defence against consumption. To test the hypothesis that bacterial species inhabiting the surface of the leaves directly affect insect performance, we combine bioassays of experimental evolution, where the microbiota of the leaves is manipulated, with mathematical models to shed some light into understanding plant-insect interactions. Our goals were three-fold. First, evaluate the type and intensity of the interactions among bacteria within the phyllosphere, within the insect gut and between both communities. Second, understand how a gradient in the result of the pairwise interactions -from mutualistic to antagonistic- promotes the assembly of a stable synthetic community from the phyllosphere. And third, evaluate how this community affect insect performance. In general, we found that the majority of the bacteria-bacteria interactions are antagonistic regardless of their provenance. Interestingly, we found reciprocal negative interactions between the phyllosphere and the gut bacteria. That is, bacteria from the phyllosphere decreased the growth rate of the gut species and vice versa. Using the results from these pairwise interactions, we were able to build a interspecies synthetic community that is stable to both biotic and abiotic disturbances. Finally, when evaluating the effect of the phyllosphere on insect performance we found that while larvae feeding on leaves without epiphytes were able to complete their development, they compensated by consuming a greater amount of foliar tissue. Interestingly, adults emerging from larvae that consumed leaves with the entire epiphytic community had a higher body mass. Overall, our results provide relevant information on the functional role played by the microorganisms in the interactions between plants and their herbivorous insects.

• Pu Wang, University of Minnesota, United States
• Michael Travisano

Evolution is a fundamentally historical process, and understanding its predictability is a key biological question. Genetic background plays an essential historical contingent role in evolution. This study aimed to disentangle this aspect using a lab-established predator-prey microcosm within the framework of eco-evolutionary feedbacks. Eco-evolutionary dynamics depend on genetic variation, with mutation being the source of this variation, potentially influencing these dynamics.
Our project used a predator-prey microcosm with the ciliate Tetrahymena thermophila consuming Pseudomonas fluorescens bacteria. Five Pseudomonas strains with distinctive pre-existing genetic variation, including mutator and maladapted genetic constraints, were subjected to predatory selection. The predator's co-evolution was avoided by using new ciliate stocks in every microcosm.\nWe observed the intensification of adaptation in prey populations due to fitness changes via eco-evolutionary feedbacks. The evolutionary responses of the five strains were compared against each other to determine the roles of genetic constraints and mutation rates in eco-evolutionary interactions. The pre- and post-predation population genome sequencing data revealed that evolved populations with lower genetic diversity had higher phenotypic diversity. These results reflect the challenges of genotype-phenotype mapping. We genome-sequenced certain colonies with new phenotypes to investigate the underlying evolutionary mechanisms. We found that potential adaptations could be limited by genetic constraints, which could be overcome by higher mutation rates. These results suggested the predictability of evolution is reduced as beneficial mutations are rare, but higher mutation rates could lead to more repeatable evolutionary consequences.
Furthermore, we simulated population growth using empirical data to further explore the roles of hypermutation and genetic constraints. The model showed that the timing of evolution is key to triggering eco-evolutionary feedbacks, and this timing is affected by the mutation rates. Together our results suggest that repeatability and predictability are strongly affected by the background genotype.

• Eneas Aguirre-von-Wobeser, Centro de Investigación en Alimentación y Desarrollo, A.C., México
• Mateo Córdoba-Agudelo, Centro de Investigación en Alimentación y Desarrollo, A.C.
• Karla Veloz-Badillo, Centro de Investigación en Alimentación y Desarrollo, A.C.
• Heriberta Hernández-Camargo, Centro de Investigación en Alimentación y Desarrollo, A.C.
• Michelle Valeria Quijano-Romano, Centro de Investigación en Alimentación y Desarrollo, A.C. , Mexico
• Montserrat Cruz-Benítez, Centro de Investigación en Alimentación y Desarrollo, A.C. , Mexico

While agricultural intensification has dominated world-wide food production in the last decades, traditional agriculture provides nourishment for millions of families world-wide. Moreover, intense use of artificial inputs in modern agriculture has displaced important microbial functions in the soil. For example, microorganisms aiding plants in resisting low humidity caused by drought, could be less competitive in irrigated plots. Understanding the role of soil microorganisms in assisting plant health and productivity could help us identify microorganisms that aid plants under stressful conditions, which could be used in the adaptation to climate change. Recently, the idea of transplanting whole microbiomes between soils has been considered as a strategy to utilize natural soil functions for agriculture. As a first step, we conducted a region-wide analysis of the soil microorganisms using metagenomics, considering 28 milpas in an elevation gradiant (600 to 2400 meters above see level), which presented changes in climate, surounding ecosystems, culture and agricultural management. We found strong effects of climate and soil physicochemical variables in the soil microbial communities. Network analysis revealed that milpa soil microorganisms are organized in coherent modules, which are in turn affected by the abiotic environment. These modules are composed of a diverse mixture of taxonomic groups, highlighting the importance of microbial interactions of different groups, for local adaptation. To test whether we could manipulate the milpa microbial communities, we conducted an experiment to transplant soil between different milpa plots. We found that, transferring a small amount of soil from donor milpas, we could alter the microbiome of receiving ones. Therefore, it could be possible to transfer whole-microbiomes from different origins, in order to aid agroecosystems to adapt to changing abiotic conditions.

• Martha Espinosa-Cantellano, Cinvestav, México
• Jonatan Castillo-Millán, Cinvestav, México
• María Gabriela Guaita-Gavilanes, Cinvestav, México
• Lizbeth Salazar-Villatoro, Cinvestav, México
• Silvia Galindo-Gómez, Cinvestav, México
• Adolfo Martínez-Palomo, Cinvestav, México

Intestinal Organoids: A Model for the Study of Communicable and Non-Communicable Diseases in Mexico\n\nMartha Espinosa-Cantellano*, Jonatan Castillo-Millán, María Gabriela Guaita-Gavilanes, Lizbeth Salazar-Villatoro, Silvia Galindo-Gómez, and Adolfo Martínez-Palomo\n\nDepartamento de Infectómica y Patogénesis Molecular, Cinvestav \n\nDigestive tract diseases include communicable diseases (spread by the transmission of infectious agents) and non-communicable diseases (developed by lifestyle, genetics, diet, pollution, or aging); both represent a significant challenge to global public health. In the 2019 WHO report, the leading causes of death in low-income countries were diarrheal diseases of viral etiology, such as those caused by rotavirus, while in middle- and high-income countries, gastric and colon cancers predominated. \n\nOur group conducts cutting-edge research in a digestive tract organoid model that replicates the cellular architecture and physiology of the tissue of origin. For communicable diseases, we apply the duodenal organoid model to investigate the non-lytic release of rotavirus through vesicles, recently described for naked viruses, seeking to contribute to the understanding of the virus's replication cycle and its pathogenicity strategies. In non-communicable diseases such as ulcerative colitis, we use the colon organoid model to study epithelial regeneration and the role of different cells in this process, with the aim of finding new therapies for inflammatory bowel diseases. \n\nIn these two projects, we use various light microscopy techniques, high-resolution confocal microscopy, transmission electron microscopy with protein immunolabeling using gold nanoparticles, and scanning electron microscopy. We also apply molecular biology and mass spectrometry techniques in proteomics, which may be of interest to BioGeoEvolution 2025 participants.\n\n*Presenting author: mespinosac@cinvestav.mx\n