Rhodopseudomonas telluris sp. nov., a phototrophic alphaproteobacterium isolated from paddy soil.

A strain of anoxygenic phototrophic bacteria isolated from paddy soil (designated strain TUT3615T) was studied taxonomically in comparison with Rhodopseudomonasstrain ATCC 17005 as its nearest phylogenetic relative. Strains TUT3615T and ATCC 17005 had budding rod-shaped cells and showed in vivo absorption maxima at 804 and 860 nm in the near infrared region, indicating the presence of bacteriochlorophyll a. The intracytoplasmic membrane system was of the lamellar type parallel to the cytoplasmic membrane. 16S rRNA gene sequence comparisons showed that strains TUT3615T and ATCC 17005 had a 99.7 % level of similarity to one another and were closest to Rhodopseudomonas palustris ATCC 17001T (98.6 % similarity) among the established species of the genus Rhodopseudomonas. Genomic DNA-DNA hybridization studies revealed that strains TUT3615T and ATCC 17005 had an average similarity level of 65 % to one another and of less than 40 % to the available type strains of Rhodopseudomonas species. Results of phenotypic studies showed that strains TUT3615T and ATCC 17005 could be differentiated from one another and from any previously described species of Rhodopseudomonas. The G+C contents of the genomic DNA of strain TUT3615T and ATCC 17005 were 66.3 and 66.5 mol%, respectively. Based on these data, we propose the name Rhodopseudomonas telluris sp. nov. for strain TUT3615T. The type strain is TUT3615T (=KCTC 23279T=NBRC 107609T). We suspend a proposal to reclassify strain ATCC 17005 as a novel species or subspecies until a genome-wide analysis provides more definite information on its taxonomic position.