RT Journal Article SR Electronic(1) A1 Kulichevskaya, Irina S. A1 Danilova, Olga V. A1 Tereshina, Vera M. A1 Kevbrin, Vadim V. A1 Dedysh, Svetlana N.YR 2014 T1 Descriptions of Roseiarcus fermentans gen. nov., sp. nov., a bacteriochlorophyll a-containing fermentative bacterium related phylogenetically to alphaproteobacterial methanotrophs, and of the family Roseiarcaceae fam. nov. JF International Journal of Systematic and Evolutionary Microbiology, VO 64 IS Pt_8 SP 2558 OP 2565 DO https://doi.org/10.1099/ijs.0.064576-0 PB Microbiology Society, SN 1466-5034, AB A light-pink-pigmented, microaerophilic bacterium was obtained from a methanotrophic consortium enriched from acidic Sphagnum peat and designated strain Pf56T. Cells of this bacterium were Gram-negative, non-motile, thick curved rods that contained a vesicular intracytoplasmic membrane system characteristic of some purple non-sulfur alphaproteobacteria. The absorption spectrum of acetone/methanol extracts of cells grown in the light showed maxima at 363, 475, 505, 601 and 770 nm; the peaks at 363 and 770 nm are characteristic of bacteriochlorophyll a. However, in contrast to purple non-sulfur bacteria, strain Pf56T was unable to grow phototrophically under anoxic conditions in the light. Best growth occurred on some sugars and organic acids under micro-oxic conditions by means of fermentation. The fermentation products were propionate, acetate and hydrogen. Slow chemo-organotrophic growth was also observed under fully oxic conditions. Light stimulated growth. C1 substrates were not utilized. Strain Pf56T grew at pH 4.0–7.0 (optimum pH 5.5–6.5) and at 15–30 °C (optimum 22–28 °C). The major cellular fatty acids were 19 : 0 cyclo ω8c and 18 : 1ω7c; quinones were represented by ubiquinone Q-10. The G+C content of the DNA was 70.0 mol%. Strain Pf56 displays 93.6–94.7 and 92.7–93.7 % 16S rRNA gene sequence similarity to members of the families Methylocystaceae and Beijerinckiaceae , respectively, and belongs to a large cluster of environmental sequences retrieved from various wetlands and forest soils in cultivation-independent studies. Phenotypic, genotypic and chemotaxonomic characteristics of strain Pf56T suggest that it represents a novel genus and species of bacteriochlorophyll a-containing fermentative bacteria, for which the name Roseiarcus fermentans gen. nov., sp. nov. is proposed. Strain Pf56T ( = DSM 24875T = VKM B-2876T) is the type strain of Roseiarcus fermentans, and is also the first characterized member of a novel family within the class Alphaproteobacteria , Roseiarcaceae fam. nov., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.064576-0