The first cultivated representatives of the actinobacterial lineage OPB41 isolated from subsurface environments constitute a novel order Anaerosomatales

Abstract

The continental subsurface harbors microbial populations highly enriched in uncultured taxa. OPB41 is an uncultured order-level phylogenetic lineage within the actinobacterial class Coriobacteriia. OPB41 bacteria have a wide geographical distribution, but the physiology and metabolic traits of this cosmopolitan group remain elusive. From two contrasting subsurface environments, a terrestrial mud volcano and a deep subsurface aquifer, located in the central part of Eurasia, within the Caucasus petroleum region, we have isolated two pure cultures of anaerobic actinobacteria belonging to OPB41. The cells of both strains are small non-motile rods forming numerous pili-like appendages. Strain M08DHBT is mesophilic, while strain Es71-Z0120T is a true thermophile having a broad temperature range for growth (25–77°C). Strain M08DHBT anaerobically reduces sulfur compounds and utilizes an aromatic compound 3,4-dihydroxybenzoic acid. Strain Es71-Z0120T is an obligate dissimilatory Fe(III) reducer that is unable to utilize aromatic compounds. Both isolates grow lithotrophically and consume molecular hydrogen or formate using either thiosulfate, elemental sulfur, or Fe(III) as an electron acceptor. Genomes of the strains encode the putative reductive glycine pathway for autotrophic CO2 fixation, Ni-Fe hydrogenases, putative thiosulfate/polysulfide reductases, and multiheme c-type cytochromes presumably involved in dissimilatory Fe(III) reduction. We propose to assign the isolated strains to the novel taxa of the species–order levels and describe strain M08DHBT as Anaerosoma tenue gen. nov., sp. nov., and strain Es71-Z0120T as Parvivirga hydrogeniphila gen. nov., sp. nov., being members of Anaerosomatales ord. nov. This work expands the knowledge of the diversity, metabolic functions, and ecological role of the phylum Actinomycetota.

Sex-Specific Effects of Polystyrene Microplastic and Lead(II) Co-Exposure on the Gut Microbiome and Fecal Metabolome in C57BL/6 Mice

“…OPB41 was significantly increased in the Pb(II)PS group in female mice, but not in male mice (Figure 1C). OPB41 is an order-level phylogenetic lineage within the class Coriobacteriia, which has a wide geographical distribution, but its physiology and metabolic traits are elusive [38].…”

Legacy copper/nickel mine tailings potentially harbor novel iron/sulfur cycling microorganisms within highly variable communities

“…Many of the most abundant lineages are taxonomically novel and/or previously not identified within mine tailings (Figure 3). The Actinobacteriota (most abundant in ML25 but present at all locations) ASVs mostly belong to the order Gaiellales (common in deep sea sediments) (Chen et al, 2021), WCHB1-81(microcystin-contaminated lakes) (Dziga et al, 2019), and OPB41 (subsurface environments) (Khomyakova et al, 2022). Other ASVs that were unclassified at the genus/species level include the Acidobacteriaceae (associated with mine tailings but highly diverse (Campbell, 2014), as shown by the fact that the two subgroups identified in this study exhibit very different localization patterns), as well as the Gemmatimonadaceae, Pirellulaceae, Comamonadaceae, Chitinophagaceae, and Caulobacteraceae, which have not previously been associated with mine tailings.…”

Structure of Benthic Microbial Communities in the Northeastern Part of the Barents Sea

“…DNA Extraction, 16S rRNA Gene-Based Profiling, and qPCR DNA from sediment samples and filters was isolated using FastDNA Spin Kit for Soil (MP Biomedicals, Irvine, CA, USA) and TissueLyser LT (QIAGEN, Hilden, Germany), according to the manufacturer's protocols. Library preparation of the V4 region of the 16S rRNA gene, sequencing, and analysis were performed as previously described [25]. Sequencing was carried out on a MiSeq system (Illumina, San Diego, CA, USA) using a reagent kit, which can read 150 nucleotides from each end.…”