Metabarcoding Analysis Reveals Microbial Diversity and Its Environmental Drivers in the Pantanos de Villa Lagoons in...

Coastal wetlands are ecosystems of ecological importance that face multiple threats from contamination. While their ecological value for local flora and fauna is well known, the microbial diversity of this habitat has not been characterized before. This study characterized, for the first time, the microbial diversity in four lagoons of the Pantanos de Villa Wildlife Refuge using the 16S rRNA marker gene metabarcoding and identified the physicochemical drivers that influence the microbial community structure of these lagoons. Nine sampling sites were established distributed across the Delicias, Génesis, Marvilla, and Mayor lagoons, conducting three seasonal samplings (May, August, and October). Physicochemical parameters were measured in each sampled lagoon (temperature, electrical conductivity, pH, dissolved oxygen, total dissolved solids, and salinity). The results revealed that the most identified phylum at the bacterial level was Pseudomonadota, followed by Bacteroidota. At the archaeal level, the abundance of Nanoarchaeota was observed in all sampled lagoons, followed by Lokiarchaeota. The Delicias lagoon, previously classified as the most contaminated lagoon in the wetland by previous studies, showed parameters such as high electrical conductivity, total dissolved solids, and salinity when compared to the other lagoons, which was reflected in a distinctive microbial community structure strongly associated with these parameters. On the other hand, the Marvilla lagoon, closer to the coast, showed a microbial community strongly influenced by its more alkalinic pH. This study constitutes the first determination of microbial diversity in Pantanos de Villa and demonstrates how local environmental conditions-natural or human-induced-shape microbial diversity. These findings provide baseline information for future monitoring of this protected coastal wetland and highlight the importance of environmental factors such as pH and electrical conductivity that determine the structure of microbial communities in these coastal wetlands.