Alkalicella caledoniensis gen. nov., sp. nov., a novel alkaliphilic anaerobic bacterium isolated from ‘La Crouen’ alkaline thermal spring, New Caledonia

Abstract

A novel anaerobic, alkaliphilic, mesophilic, Gram-stain-positive, endospore-forming bacterium was isolated from an alkaline thermal spring (42 °C, pH 9.0) in New Caledonia. This bacterium, designated strain LB2T, grew at 25–50 °C (optimum, 37 °C) and pH 8.2–10.8 (optimum, pH 9.5). Added NaCl was not required for growth (optimum, 0–1 %) but was tolerated up to 7 %. Strain LB2T utilized a limited range of substrates, such as peptone, pyruvate, yeast extract and xylose. End products detected from pyruvate fermentation were acetate and formate. Both ferric citrate and thiosulfate were used as electron acceptors. Elemental sulphur, nitrate, nitrite, fumarate, sulphate, sulfite and DMSO were not used as terminal electron acceptors. The two major cellular fatty acids were iso-C15 : 0 and C16 : 0. The genome consists of a circular chromosome (3.7 Mb) containing 3626 predicted protein-encoding genes with a G+C content of 36.2 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the isolate is a member of the family Proteinivoraceae , order Clostridiales within the phylum Firmicutes . Strain LB2T was most closely related to the thermophilic Anaerobranca gottschalkii LBS3T (93.2 % 16S rRNA gene sequence identity). Genome-based analysis of average nucleotide identity and digital DNA–DNA hybridization of strain LB2T with A. gottschalkii LBS3T showed respective values of 70.8 and 13.4 %. Based on phylogenetic, genomic, chemotaxonomic and physiological properties, strain LB2T is proposed to represent the first species of a novel genus, for which the name Alkalicella caledoniensis gen. nov., sp. nov. is proposed (type strain LB2T=DSM 100588T=JCM 30958T).

The Chemistry of Hyperalkaline Springs in Serpentinizing Environments: 1. The Composition of Free Gases in New Caledonia Compared to Other Springs Worldwide

“…Although they have been included in previous studies of New Caledonia alkaline springs [Cox et al, 1982;Deville and Prinzhofer, 2016;Vacquand et al, 2018], the springs of the Canala area are somewhat different than those further South. The geological substratum is different and the pH (≈ 9) of its waters is lower than that at the other studied sites [Cox et al, 1982;Maurizot et al, 2020;Quéméneur et al, 2021].…”

Methanobacterium alkalithermotolerans sp. nov., a novel alkaliphilic and hydrogen-utilizing methanogen isolated from an alkaline geothermal spring (La Crouen, New Caledonia)

“…For enrichment experiments, a sediment slurry sample was collected in November 2014 using both sterilized spatula and glass bottle from the geothermal spring of La Crouen (165° 53′ 20.6″ E 21° 32′ 06.6″ S), located next to the city of Canala (New Caledonia) [13]. For preserving anoxic conditions, the bottle was immediately hermetically sealed and stored at 4 °C.…”

“…High molecular weight DNA of the isolate and M. alcaliphilum DSM 3459 was extracted using a phenol-chloroform method [28] modified by adding a step including several cycles of grinding the frozen cell pellet in liquid nitrogen to optimize cell wall lysis. Whole genomes were then sequenced at the GeT-PlaGe platform (INRAe Toulouse, France) by combining long-read (Oxford Nanopore) and short-read (Illumina MiSeq) technologies, as described by Quéméneur et al [13]. The genomes of the isolate and M. alcaliphilum DSM 3459 were assembled with Unicycler version 0.4.6 [29] and SPAdes version 3.7.1 [30].…”

Insights into the physiological and genomic characterization of three bacterial isolates from a highly alkaline, terrestrial serpentinizing system

“…strain NSHQ4 from Samail Ophiolite ( Miller et al, 2018 ), and others from Cabeço de Vide ( Tiago et al, 2004 ) and Zambales Ophiolite ( Vallalar et al, 2019 ). Besides ophiolites, there are also microbes isolated from marine serpentinite-hosted ecosystems, such as Alkalicella caledoniensis ( Quéméneur et al, 2021 ) and Alkaliphilus sp. ( Postec et al, 2021 ).…”