Differences in temperature and water chemistry shape distinct diversity patterns in thermophilic microbial communities.

This study presents the biodiversity and ecology of microbial mats developed in thermal gradients (20-65 °C) in the surroundings of three drillings (CH, CI, MB) tapping a hyperthermal aquifer from Romania. Using a metabarcoding approach, 16S rRNA genes were sequenced from both DNA and RNA transcripts (cDNA) and compared. The relationships between the microbial diversity and the physico-chemical factors were explored. Additionally, the cDNA data was used for in silico functionality predictions, bringing new insights into the functional potential and dynamics of these communities. The results showed that each hot spring determined the formation of distinct microbial communities. In the CH mats (40-53 °C), the abundance of Cyanobacteria decreased with temperature, opposite to that of Chloroflexi and Proteobacteria. Ectothiorhodospira, Oscillatoria and methanogenic archaea dominated the CI communities (20-65 °C), while the MB microbial mats (53-65 °C) were mainly composed of Chloroflexi, Hydrogenophilus, Thermi and Aquificae. Alpha diversity was negatively correlated with the increase in water temperature, while beta diversity was shaped in each hot spring by the unique combination of physico-chemical parameters, regardless of the type of nucleic acid analyzed (DNA vs. cDNA). The rank correlation analysis revealed a unique model that associated environmental data with community composition, consisting in the combined effect of Na(+), K(+), HCO3(-), PO4(3-) concentrations, tog...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research