Posters - Schedules

Calakmul is a tropical forest located in Campeche, cultural heritage of humanity, recognized as one of the most significant urban centers of Mayan world. It has depressions that are associated with faults and geological fractures that allow the accumulation of water in the rainy season forming what has been called ""aguadas"". Associated with the climate, vegetation and animals of the tropical forest, the disturbance by human settlements in some areas causes variations in microbial communities, which are of great importance for the micro biodiversity of the reserve.
Our objective is to show a preliminary view of the structure of the bacterial communities, the dynamics and interactions of the microorganisms that inhabit them over the years, as well as the differences between sites. In addition, we seek to determine the metabolic capabilities of specific bacterial groups that could be mediating these interactions. This is due to the importance of these soils as sinks, carbon sources and their role in climate change.
Therefore, the microbiota of three different ponds, two belonging to the undisturbed core zone (Ag1 and Ag2), and one from the buffer zone (Ag3), were characterized in three different years. A spatiotemporal sampling and sequencing of metagenomes by 16S rRNA amplicons and shotgun sequencing using next generation technology (NGS) approximated the diversity changes of the bacterial communities.
The alpha diversity analyses of the 3 zones show that there is a lower diversity in Ag1 with respect to Ag2 and Ag3, although the Ag2 zone presents a higher abundance of species. As for beta diversity, it is suggested that the bacterial community of Ag1 is less diverse than Ag2 and Ag3, since the samples taken from this zone are better clustered. In addition, when compared at the zone level, they are observed to be far apart from each other, suggesting that this behavior is marked by the territorial location of where the sample was taken, hence, a diverse community of microorganisms. In summary, the three sites have a unique composition of microorganisms, as they do not cluster together; therefore, the chemical composition of the sites could determine the microbial structure of the ""aguadas"".
Taxonomic results show that the bacterial communities comprise mainly genera and phyla, of Proteobacteria, Acidobacteria and Actinobacteria. This demonstrates the richness of the bacterial community composition and lays the foundation for the association between the microbiota and the tropical ecosystem where the aguada is located.

The fungal genus Fusarium comprises both plant pathogenic and non-pathogenic species. Pathogenic species affect a high number of agricultural important crops worldwide, such as tomato, vanilla, banana and cucumber. Among the pathogenic species we can find a major plant pathogen complex species, Fusarium oxysporum, which is known for developing a narrow specificity for its hosts, leading to the sub-species classification of forma specialis. The pathogenicity potential of an organism can be studied through the detection of Biosynthetic Gene Clusters, which are physically clustered groups of two or more genes that together encode a biosynthetic pathway for the production of a specialized metabolite. In Fusarium oxysporum, BGC have been found to be related to the pathogenicity process, due to the production of secondary metabolites involved in the infection of the host, such as Fusaric Acid (FA) and Fumonisin (Fu). In this work, the genome sequences of two Fusarium species (Fusarium verticillioides and Fusarium irregulare) found in both diseased and healthy vanilla plants were mined to obtain BGC and compare them against those of Fusarium oxysporum formae speciales available through public repositories. We found that some pathogenicity-related BGC were present in the genome of the Fusarium found in the diseased vanilla, while absent in the other one. These same BGC were common to most pathogenic formae speciales, suggesting they play an important role in the pathogenicity process. This study arises the potential of BGC detection as an aproach to differentiate between pathogenic and non-pathogenic fungi species, as well as to understand the mechanisms underlaying the pathogenicity phenomenon.

The Cuatro Ciénegas Basin (CCB), Coahuila, Mexico, is a small, butterfly-shaped valley located about 740 m above sea level and surrounded by mountains that rise to over 2,500 m. Recently in 2016, Archean Domes (AD) was discovered to have a microbial mat with dome-like structures with a strong sulfur-like odor. In a sampling carried on September 2016 revealed a physicochemical salinity of 5.3 PSU and a pH of 9.94 . Given the physicochemical conditions of salinity and pH, it could be concluded that the site is a suitable environment for extremophile organisms to proliferate. In this analysis, we report the sequencing of 329 metagenome-assembled genomes (MAGs) which were classified in the domains Archaea (52) and Bacteria (277). 30 out of 52 total MAGs of archaea, could not be classified at the genus level, and none of them were classified to the species level. For Bacteria MAGs 154 out of 277 were not classified at genus level and just three of them were classified at species level. Within this set of MAGs, the 4 MAGs classified within the superphylum Asgardarchaeota stand out, which has been recently described by culture-independent techniques and there is just one Lokiarchaeia cultured report which has been called Prometheoarchaeum syntrophicum (Imachi et al., 2020)