Rhodopseudomonas pentothenatexigens sp. nov. and Rhodopseudomonas thermotolerans sp. nov., isolated from paddy soils

Abstract

Two strains (JA575T and JA576T) of orange-to pink-pigmented, rod-shaped, motile and budding phototrophic bacteria were isolated from paddy soils. Both strains contained bacteriochlorophyll a and carotenoids of spirilloxanthin series. Both strains had C18: 1ω7c as the major cellular fatty acid, ubiquinone-10 (Q10) as the main quinone, and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine as polar lipids. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that both strains clustered with species of the genus Rhodopseudomonas in the class Alphaproteobacteria. Strains JA575T and JA576T were genotypically ( < 35% DNA-DNA relatedness) and phenotypically distinct from each other. Further, both strains showed less than 48% DNA-DNA relatedness with the type strains of all recognized species of the genus Rhodopseudomonas. The molecular evidence is supported by phenotypic evidence. It is proposed that strains JA575T and JA576T be classified as representing two novel species of the genus Rhodopseudomonas with the species names Rhodopseudomonas pentothenatexigens sp. nov. and Rhodopseudomonas thermotolerans sp. nov., respectively. The type strains of the proposed novel species are JA575T (5NBRC 108862T5KCTC15143T) and JA576T (5NBRC 108863T5KCTC 15144T), respectively. © 2013 IUMS.