Microbiological analysis of peat therapeutic mud from the Taborli-3 deposit

Peat mud (peloids) are natural organomineral complexes formed during the decomposition of organic residues in swampy areas under conditions of lack of oxygen. They have a high heat capacity and contain biologically active substances (salts, gases, biostimulants, metabolites of organisms, etc.), as well as living microorganisms. However, the microbial composition of peloids is practically unknown. The purpose of the work was to analyze the microbial composition of peat peloids from the Taborli-3 deposit (Tatarstan Republic) according to sanitary and bacteriological characteristics, the range of cultivated microorganisms, molecular-genetic determination of the prokaryotic metagenome and its functional potential. During 2021-2023 7 samples of peloids from the Taborli-3 deposit were studied. Sanitary and bacteriological analysis was carried out in accordance with the control program of sanatoriums using this mud. Taxonomic identification of the isolated microorganism cultures was carried out using time-of-flight mass spectrometry with matrix-assisted laser desorption/ionization MALDI-TOF MS. Molecular-genetic analysis of the microbial community was performed by sequencing 16S rRNA using Illumina MiSeq, subsequent sequence analysis was carried out using the Mothur software package on Galaxy platform. Bacterial communities of peloids were characterized, the dominance of representatives of the phyla Firmicutes (22%) and Proteobacteria (36%) was established. At the family level, Streptococcaceae, Ruminicoccaceae, Lactobacillaceae, Comamondaceae and Sphingomonadaceae were dominant. The functional potential of the communities confirms that peloid bacteria contain the main genes for the metabolism of carbohydrates, lipids, vitamins, amino acids and nucleotides, and are also capable to utilize xenobiotics. The microbiome of therapeutic mud from the Taborli-3 deposit was characterized for the first time. Monitoring the composition of microbial communities of therapeutic mud is an important component for assessing the contribution of microorganisms and their metabolites to the healing effect of peloid therapy.