1. 'Candidatus Chloroploca mongolica' sp. nov. a new mesophilic filamentous anoxygenic phototrophic bacterium.
- Author
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Bryantseva, Irina A, Grouzdev, Denis S, Krutkina, Maria S, Ashikhmin, Aleksandr A, Kostrikina, Nadezda A, Koziaeva, Veronika V, and Gorlenko, Vladimir M
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PHOTOSYNTHETIC bacteria , *CANDIDATUS , *NITROGEN fixation , *ANAEROBIC bacteria , *MICROBIAL mats , *GLUTAMINE synthetase , *QUINONE , *OXIDOREDUCTASES - Abstract
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 β- and γ-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 CO2 assimilation. The genome also contained the genes encoding a type IV sulfide:quinone oxidoreductase (sqrX). The organism had no nifHDBK 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. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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