Microbiology, 卷 93, 编号 5 (2024)

A comparative analysis of carbohydrate degradation proteins encoded in currently available genomic sequences of bacteria of the family Sphaerochaetaceae, namely Sphaerochaeta associata GLS2^T, S. globosa Buddy^T, S. pleomorpha Grapes^T, S. halotolerans 4-11^T, S. halotolerans 585, Sphaerochaeta sp. S2, Sphaerochaeta sp. PS and Parasphaerochaeta coccoides SPN1^T was carried out. The genomes of Sphaerochaeta spp. encode a medium-sized and diverse set of proteins potentially involved in the degradation of different classes of carbohydrates, mainly oligosaccharides. All studied genomes encode glycoside hydrolases of the GH1, GH2, GH3, GH4, GH13, GH20, GH28, GH36, GH43, GH57, GH63, GH77 and GH105 families, as well as carbohydrate esterases of the CE8 and CE9 families. All studied bacteria, with the exception of P. coccoides SPN1^T, have many proteins of the GH31 family encoded in their genomes. The studied representatives of Sphaerochaetaceae do not have genes coding for endo-β-acetylmuramidase (lysozyme) of the GH23 family involved in the process of peptidoglycan turnover. However, the genomes of S. associata, S. globosa, Sphaerochaeta sp. PS and S. pleomorpha contain the exo-β-acetylmuramidase gene (GH171 family). A significant part of the genes encoding carbohydrate degradation enzymes have the closest homologues among representatives of the phyla Bacillota, Bacteroidota, and Pseudomonadota. The genomes of the studied bacteria encode proteins that could potentially be involved in the degradation of pectin. The ability of representatives of Sphaerochaetaceae to use pectin for growth, as well as the evolutionary origin of genes encoding potential α-galacturonidase (GH4 family) and unsaturated glucuronyl/rhamnogalacturonyl hydrolase (GH105 family), involved in the degradation of pectin components, were studied.