In this research, the thermophilic microbial composition of samples from four areas of the Tecozautla geyser, Hidalgo, Mexico, was studied. The samples were: sediments (GD), salt deposits (GA), and microbial mats (GB and GC). Sequencing of the 16S rRNA gene amplicons was carried out, obtaining 1,425,506 readings. Bioinformatic analysis identified 32 phyla in the four samples being the most representative for the GA Armatimonadetes, Chloroflexi, Cyanobacteria, and Thermi. For the GB, they were Proteobacteria, Bacteroidetes, Cyanobacteria, Spirochaetes, Thermi, and Firmicutes. For the GC were observed the phyla Chloroflexi, Armatimonadetes, Proteobacteria, Cyanobacteria, and Acidobacteria. Finally, for the GD, the most abundant phyla were Chloroflexi, Cyanobacteria, Armatimonadetes, Proteobacteria, and Nitrospirae. The metabolic functionality of the microbial communities present in the samples was inferred using the 16S rRNA amplicons. This work represents the first report of the microbial communities present in the Tecozautla geyser.

Microbial mats have been studied in many thermal systems; the most iconic is Yellowstone. In Mexico, the information on microbial mats is scarce and therefore novel. In this research, the thermophilic microbial composition of samples from four areas of the Tecozautla geyser, Hidalgo, Mexico, was studied: sediments (GD), salt deposits (GA), and microbial mats (GB and GC). The samples were taken at the outlet of the geyser (94 °C) and in storage pools with temperatures of 61.5-65 °C. Sequencing of the 16S rRNA gene amplicons was carried out, obtaining 1,425,506 readings, and was analyzed through the Quantitative Insights Into Microbial Ecology software package version 2 (qiime2). 32 phyla were identified in the four samples being the most representative for the GA sample: Armatimonadetes, Chloroflexi, Cyanobacteria, and Thermi, with abundances of 46.35, 19.18, 3.27, and 1.82 %, respectively. For the GB sample, they were Proteobacteria, Bacteroidetes, Cyanobacteria, Spirochaetes, Thermi, and Firmicutes with abundances of 25.23, 22.04, 20.42, 12.31, 4.56, and 1.32 %, respectively. For the GC sample, abundances of 55.60, 9.85, 7.04, 7.01, and 6.15 % were observed for the phylum Chloroflexi, Armatimonadetes, Proteobacteria, Cyanobacteria, and Acidobacteria, respectively. Finally, for the GD sample, the most abundant phyla were Chloroflexi (36.10 %), Cyanobacteria (17.13 %), Armatimonadetes (15.59 %), Proteobacteria (5.45 %), and Nitrospirae with (3.21 %). The metabolic functionality of the microbial communities present in the samples was inferred using the 16S rRNA amplicons. This work represents the first report of the microbial communities present in the Tecozautla geyser.