Thermodesulfobium acidiphilum sp. nov., a thermoacidophilic, sulfate-reducing, chemoautotrophic bacterium from a thermal site

Abstract

An obligately anaerobic, sulfate-reducing micro-organism, strain 3127-1T, was isolated from geothermally heated soil (Oil Site, Uzon Caldera, Kamchatka, Russia). The new isolate was a moderately thermoacidophilic anaerobe able to grow with H2 or formate by respiration of sulfate or thiosulfate. The pH range for growth was 3.7-6.5, with an optimum at 4.8-5.0. The temperature range for growth was 37-65 °C, with an optimum at 55 °C. The G+C content of the genomic DNA was 33.7 mol%. The genome of strain 3127-1T contained two almost identical 16S rRNA genes, differing by a single nucleotide substitution. The closest 16S rRNA gene sequence of a validly published species belonged to Thermodesulfobium narugense Na82T (99.5 % similarity). However, the average nucleotide identity of the genomes of strain 3127-1T and T. narugense Na82T and the predicted DNA-DNA hybridization value (GGDC 2.1 blast+, formula 2) were as low as 86 and 32.5±2.5 %, respectively. This, together with phenotypic data, showed the new isolate to belong to a novel species, for which the name Thermodesulfobium acidiphilum sp. nov. is proposed. The type strain is 3127-1T (=DSM 102892T=VKM B-3043T).

Form III RubisCO-mediated transaldolase variant of the Calvin cycle in a chemolithoautotrophic bacterium

“…Analysis of the Thermodesulfobium acidiphilum Genome. In our recent study of sulfate reduction in acidic hot springs, an autotrophic sulfate-reducing bacterium, Thermodesulfobium acidiphilum strain 3127-1 T , was isolated and characterized (20). This bacterium, together with Thermodesulfobium narugense Na82 T , represents the family Thermodesulfobiaceae (21), which, according to the latest Bergey's Manual (22), is assigned to the class Clostridia of the phylum Firmicutes.…”

“…T. acidiphilum is an obligate autotroph growing on H 2 or formate via sulfate or thiosulfate respiration (20), as shown in Fig. 3.…”

“…T. acidiphilum 3127-1 T (=DSM 102892 T =VKM B-3043 T ) was isolated from geothermally heated soil sampled at the Oil Site, Uzon Caldera, Kronotsky Nature Reserve, Kamchatka, Russia (N54°30.023′ E160°00.088′, elevation 654 m) in August 2014. T. acidiphilum was grown under anaerobic conditions on a chemically defined medium (20) with CO 2 as the carbon source, H 2 as the electron donor, and sulfate as the electron acceptor. Genome Sequencing and Assembly.…”

Thermodesulfobium sp. strain 3baa, an acidophilic sulfate reducing bacterium forming biofilms triggered by mineral precipitation

“…The 16S-rRNA gene of sulfate reducing strain 3baa (1442 nucleotides) exhibited 98% sequence similarity to the 16S rRNA gene of T. narugense Na82 T and T. acidiphilum 3127-1 T . T. narugense Na82 T was isolated from pHneutral hot spring Narugo in Miyagi, Japan (58 C, pH 6.9; Mori et al, 2003) and T. acidiphilum 3127-1 T was isolated from acidic thermal spring Oil site of the Uzon caldera, Kamchatka, Russia (60 C, pH 4.8;Frolov et al, 2017). Interestingly, strain 3baa forms a separate cluster with two sequences obtained from enrichments or directly from sediments of acidic Rio Tinto, Spain (HQ730662, JQ420033; Sánchez-Andrea et al, 2011; 2013) ( Fig.…”

“…Only few acid tolerant or (moderate) acidophilic sulfate reducing species have been validly described so far. These include the mesophiles Desulfosporosinus acidiphilus (Alazard et al, 2010) and Desulfosporosinus acididurans (Sánchez-Andrea et al, 2015) as well as the thermophiles Thermodesulfobium narugense (Mori et al, 2003) and Thermodesulfobium acidiphilum (Frolov et al, 2017) within the Clostridia. For a putatively acid tolerant member of the Deltaproteobacteria, Desulfovibrio sp.…”