Abstract
Phenotypic and phylogenetic studies were performed with two strains (OCh 239(T) and OCh 210(T), T=type strain) of aerobic bacteriochlorophyll-containing bacteria isolated from the charophytes and the epiphytes on the stromatolites, respectively, of a saline lake located on the west coast of Australia. Both strains were chemoheterotrophic, Gram-negative and motile rods with subpolar flagella. Catalase and oxidase were produced. ONPG reaction was positive. Cells utilized D-glucose, acetate, butyrate, citrate, DL-lactate, DL-malate, pyruvate, succinate, L-aspartate and L-glutamate. Acids were produced from D-fructose and D-glucose. Bacteriochlorophyll a was synthesized under aerobic conditions. Strain OCh 239(T) had nitrate reductase and phosphatase. Acids were produced from L-arabinose, D-galactose, lactose, maltose, D-ribose and sucrose. The strain could grow in 0--20.0% (w/v) NaCl. Strain OCh 210(T) had urease. Hydrolysis of gelatin was positive. Acids were produced from D-xylose. The strain could grow in 0.5--20.0% (w/v) NaCl. The results of 16S rRNA sequence comparisons revealed that strains OCh 239(T) and OCh 210(T) formed a new cluster within the alpha-3 group of the alpha subclass of the class Proteobacteria. The similarity value of the 16S rRNA sequences between strains OCh 239(T) and OCh 210(T) was 95.8%. Therefore, it was concluded that these two strains should be placed in a new genus, Roseivivax gen. nov., as the new species Roseivivax halodurans sp. nov. and Roseivivax halotolerans sp. nov. The type species of the genus is Roseivivax halodurans. The type strains of Roseivivax halodurans and Roseivivax halotolerans are OCh 239(T) (=JCM 10272(T)) and OCh 210(T) (=JCM 10271(T)), respectively.