# Description and Genomic Analysis of the First Facultatively Lithoautotrophic, Thermophilic Bacteria of the Genus Thermaerobacter Isolated from Low-temperature Sediments of Lake Baikal.
> バイカル湖低温堆積物から単離されたThermaerobacter属初の通性独立栄養性好熱菌のゲノム解析


## Abstract

A novel thermophilic bacterium, strain PB12/4term (=VKM B-3151), was recovered from low-temperature surface sediments near the Posolsk Bank methane seep in Lake Baikal, Russia. Unlike previously described members of the genus Thermaerobacter, this strain exhibits facultative lithoautotrophy, utilizing molecular hydrogen as an electron donor, elemental sulfur and thiosulfate as electron acceptors, and CO/CO₂ as carbon sources. The genome comprises a single chromosome of 2,820,915 bp with a G+C content of 72.2%. Phylogenomic analysis based on 120 conserved single-copy bacterial proteins placed the strain within the class Thermaerobacteria, phylum Firmicutes_E, showing closest relatedness to Thermaerobacter subterraneus DSM 13965 (ANI=95.08%) and Thermaerobacter marianensis DSM 12885 (ANI=84.98%). The capacity for lithoautotrophic growth is attributed to the presence of [NiFe]hydrogenase genes, which are absent in both reference strains. These findings expand understanding of metabolic diversity within the genus Thermaerobacter.

### Mechanism

Strain PB12/4term encodes [NiFe]hydrogenase enzymes enabling use of molecular hydrogen as an electron donor coupled to reduction of elemental sulfur or thiosulfate, supporting facultative lithoautotrophic growth absent in related Thermaerobacter species.

## Bibliographic

- **Authors**: Pavlova ON, Tupikin AE, Chernitsyna SM, Bukin YS, Lomakina AV, Pogodaeva TV, et al.
- **Journal**: Microb Ecol
- **Year**: 2023
- **PMID**: [36717392](https://pubmed.ncbi.nlm.nih.gov/36717392/)
- **DOI**: [10.1007/s00248-023-02182-1](https://doi.org/10.1007/s00248-023-02182-1)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 36717392. https://h2-papers.org/en/papers/36717392
> **Source**: PubMed PMID [36717392](https://pubmed.ncbi.nlm.nih.gov/36717392/)