RESUMO
A Gram-stain-positive bacterium, strain LZ-22T, was isolated from a rhizosphere of moss Leptobryum sp. collected at the shore of Lake Zub in Antarctica. Cells were motile, straight or pleomorphic rods with sizes of 0.6-1.0×3.5-10 µm. The novel isolate was a facultatively anaerobic, catalase-positive, psychrotolerant mesophile. Growth was observed at 3-41 °C (optimum 24-28 °C), with 0-7 % (w/v) NaCl (optimum 0.25 %) and at pH 4.0-9.0 (optimum pH 7.8). The quinone system of strain LZ-22T possessed predominately menaquinone MK-9(H4). The genomic G+C content was 70.2 mol%. Strain 10J was isolated from a biofilm of sediment microbial fuel cell, in Uruguay and had 99 % 16S rRNA gene sequence similarity to strain LZ-22T. DNA-DNA-hybridization values of 84 % confirmed that both strains belonged to the same species. Both strains grew on sugars, proteinaceous compounds, and some amino- and organic acids. Strain LZ-22T uniquely grew on D-enantiomers of histidine and valine while neglecting growth on L-enantiomers. Both strains were sensitive to most of the tested antibiotics but resistant to tested nitrofurans and sulfanilamides. Phylogenetic analyses of the 16S rRNA gene sequences indicated that the strains were related to members of the family Propionibacteriaceae (~93-94 % 16S rRNA gene sequence similarity) with formation of a separate branch within the radiation of the genera Granulicoccus and Luteococcus. Based on phenotypic and genotypic characteristics, we propose the affiliation of both strains into a novel species of a new genus. The name Raineyella antarctica gen. nov., sp. nov. is proposed for the novel taxon with the type strain LZ-22T (=ATCC TSD-18T=DSM 100494T=JCM 30886T).
