AUTHOR=Wang Guanghua , Li Yuanjin , Liu Jianfeng , Chen Biao , Su Hongfei , Liang Jiayuan , Huang Wen , Yu Kefu 

TITLE=Comparative Genomics Reveal the Animal-Associated Features of the Acanthopleuribacteraceae Bacteria, and Description of Sulfidibacter corallicola gen. nov., sp., nov.

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.778535

DOI=10.3389/fmicb.2022.778535

ISSN=1664-302X

ABSTRACT=<p>Members of the phylum <italic>Acidobacteria</italic> are ubiquitous in various environments. Soil acidobacteria have been reported to present a variety of strategies for their success in terrestrial environments. However, owing to lack of pure culture, information on animal-associated acidobacteria are limited, except for those obtained from 16S rRNA genes. To date, only two acidobacteria have been isolated from animals, namely strain M133<sup>T</sup> obtained from coral <italic>Porites lutea</italic> and <italic>Acanthopleuribacter pedis</italic> KCTC 12899<sup>T</sup> isolated from chiton. Genomics and physiological characteristics of strain M133<sup>T</sup> and <italic>A. pedis</italic> KCTC 12899<sup>T</sup> were compared with 19 other isolates (one strain from each genus) in the phylum <italic>Acidobacteria</italic>. The results revealed that strain M133<sup>T</sup> represents a new species in a new genus in the family <italic>Acanthopleuribacteraceae</italic>. To date, these two <italic>Acanthopleuribacteraceae</italic> isolates have the largest genomes (10.85–11.79 Mb) in the phylum <italic>Acidobacteria</italic>. Horizontal gene transfer and gene duplication influenced the structure and plasticity of these large genomes. Dissimilatory nitrate reduction and abundant secondary metabolite biosynthetic gene clusters (including eicosapentaenoic acid <italic>de novo</italic> biosynthesis) are two distinct features of the <italic>Acanthopleuribacteraceae</italic> bacteria in the phylum <italic>Acidobacteria</italic>. The absence of glycoside hydrolases involved in plant polysaccharide degradation and presence of animal disease-related peptidases indicate that these bacteria have evolved to adapt to the animal hosts. In addition to low- and high-affinity respiratory oxygen reductases, enzymes for nitrate to nitrogen, and sulfhydrogenase were also detected in strain M133<sup>T</sup>, suggesting the capacity and flexibility to grow in aerobic and anaerobic environments. This study highlighted the differences in genome structure, carbohydrate and protein utilization, respiration, and secondary metabolism between animal-associated acidobacteria and other acidobacteria, especially the soil acidobacteria, displaying flexibility and versatility of the animal-associated acidobacteria in environmental adaption.</p>