Rhizorhabdus antheiae sp. nov. and Sphingomonas eleionomae sp. nov., new aerobic anoxygenic phototrophs isolated from a Manitoban marsh

A peach-pigmented strain FW153^T and a yellow-pigmented FW199^T were isolated from marsh water located at Fort Whyte, Manitoba, Canada. Both produce an anoxygenic photosynthetic apparatus, with a reaction centre encircled by a light-harvesting I complex containing bacteriochlorophyll <i>a</i>. They do not produce RuBisCo and do not grow anaerobically or autotrophically, supporting the classification of both as aerobic anoxygenic phototrophs. Sequencing of the 16S rRNA gene showed similarity to <i>Rhizorhabdus phycosphaerae</i> (99.93%), <i>Rhizorhabdus wittichii</i> (98.73%) and <i>Rhizorhabdus histidinilytica</i> (98.52%) for FW153^T, while for FW199^T, it was <i>Sphingomonas molluscorum</i> (97.47%), <i>Sphingomonas dokdonensis</i> (97.44%) and <i>Sphingomonas kyeonggiensis</i> (97.08%). Polyphasic analysis identified differences in physiology and cellular fatty acid composition, as well as within the genome, with average nucleotide identity (<95%) and digital DNA-DNA hybridization values (<70%) between each strain and their closest relatives supporting species designation. Therefore, we propose that FW153^T (=NCIMB 15610^T=DSM 120042^T) and FW199^T (=NCIMB 15611^T=DSM 120043^T) be classified as the type strains of new species with the names <i>Rhizorhabdus antheiae</i> sp. nov. and <i>Sphingomonas eleionomae</i> sp. nov., respectively.