Published In

International Journal of Systematic and Evolutionary Microbiology

Document Type

Article

Publication Date

1-24-2023

Subjects

Bacterial genomes, Hyperthermohphilic methanogens

Abstract

Three hyperthermohphilic methanogens, designated strain SG7T, strain SG1 and strain SLH, were isolated from the ABE and Tu’i Malila deep-sea hydrothermal vent fields along the Eastern Lau Spreading Center. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strains SG7T, SG1 and SLH were affiliated with the genus Methanocaldococcus within the family Methanocaldococcaceae, order Methanococcales. They shared 95.5–99.48 % 16S rRNA gene sequence similarity to other Methanocaldococcus species and were most closely related to Methanocaldococcus bathoardescens. Cells of strains SG7T, SG1 and SLH were cocci, with a diameter of 1.0–2.2 µm. The three strains grew between 45 and 93 °C (optimum, 80–85 °C), at pH 5.0–7.1 (optimum pH 6.2) and with 10–50 g l−1 NaCl (optimum 20–25 g l−1). Genome analysis revealed the presence of a 5.1 kbp plasmid in strain SG7T. Based on the results of average nucleotide identity and digital DNA–DNA hybridization analyses, we propose that strains SG1 and SG7T are representatives of a novel species, for which the name Methanocaldococcus lauensis sp. nov. is proposed; the type strain is SG7T (=DSM 109608T=JCM 39049T).

Rights

Copyright (c) 2023 The Authors

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

DOI

10.1099/ijsem.0.005646

Persistent Identifier

https://archives.pdx.edu/ds/psu/39321

Included in

Biology Commons

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