e-Article
'Candidatus Chloroploca mongolica' sp. nov. a new mesophilic filamentous anoxygenic phototrophic bacterium
RESEARCH LETTER -Taxonomy, Systematics & Evolutionary Microbiology
RESEARCH LETTER -Taxonomy, Systematics & Evolutionary Microbiology
Document Type
Report
Author
Source
FEMS Microbiology Letters. August 15, 2021, Vol. 368 Issue 16, p1e, 10 p.
Subject
Language
English
ISSN
0378-1097
Abstract
INTRODUCTION The term filamentous anoxygenic phototrophic bacteria (FAP) is used to designate the phototrophic members of the phylum Chloro/Iexota (previously Chloroflexi; Hanada 2014; Thiel, Tank and Bryant 2018). Both thermophilic [...]
A mesophilic filamentous anoxygenic phototrophic bacterium, designated M50-1, was isolated from a microbial mat of the Chukhyn Nur soda lake (northeastern Mongolia) with salinity of 5-14 g/L and pH 8.0-9.3. The organism is a strictly anaerobic phototrophic bacterium, which required sulfide for phototrophic growth. The cells formed short undulate trichomes surrounded by a thin sheath and containing gas vesicles. Motility of the trichomes was not observed. The cells contained chlorosomes. The antenna pigments were bacteriochlorophyll d and p- and y -carotenes. Analysis of the genome assembled from the metagenome of the enrichment culture revealed all the enzymes of the 3-hydroxypropionate bi-cycle for autotrophic [CO.sub.2] assimilation. The genome also contained the genes encoding a type IV sulfide:quinone oxidoreductase (sqrX). The organism had no ni/HDBK genes, encoding the proteins of the nitrogenase complex responsible for dinitrogen fixation. The DNA G + C content was 58.6%. The values for in silico DNA-DNA hybridization and average nucleotide identity between M50-1 and a closely related bacterium 'Ca. Chloroploca asiatica' B7-9 containing bacteriochlorophyll c were 53.4% and 94.0%, respectively, which corresponds to interspecies differences. Classification of the filamentous anoxygenic phototrophic bacterium M50-1 as a new 'Ca. Chloroploca' species was proposed, with the species name 'Candidatus Chloroploca mongolica' sp. nov. Keywords: Chloroflexota phylum; filamentous anoxygenic phototrophic bacteria; 'Candidatus Chloroploca mongolica' sp. nov
A mesophilic filamentous anoxygenic phototrophic bacterium, designated M50-1, was isolated from a microbial mat of the Chukhyn Nur soda lake (northeastern Mongolia) with salinity of 5-14 g/L and pH 8.0-9.3. The organism is a strictly anaerobic phototrophic bacterium, which required sulfide for phototrophic growth. The cells formed short undulate trichomes surrounded by a thin sheath and containing gas vesicles. Motility of the trichomes was not observed. The cells contained chlorosomes. The antenna pigments were bacteriochlorophyll d and p- and y -carotenes. Analysis of the genome assembled from the metagenome of the enrichment culture revealed all the enzymes of the 3-hydroxypropionate bi-cycle for autotrophic [CO.sub.2] assimilation. The genome also contained the genes encoding a type IV sulfide:quinone oxidoreductase (sqrX). The organism had no ni/HDBK genes, encoding the proteins of the nitrogenase complex responsible for dinitrogen fixation. The DNA G + C content was 58.6%. The values for in silico DNA-DNA hybridization and average nucleotide identity between M50-1 and a closely related bacterium 'Ca. Chloroploca asiatica' B7-9 containing bacteriochlorophyll c were 53.4% and 94.0%, respectively, which corresponds to interspecies differences. Classification of the filamentous anoxygenic phototrophic bacterium M50-1 as a new 'Ca. Chloroploca' species was proposed, with the species name 'Candidatus Chloroploca mongolica' sp. nov. Keywords: Chloroflexota phylum; filamentous anoxygenic phototrophic bacteria; 'Candidatus Chloroploca mongolica' sp. nov