Apolloniradiicaulis salifontis gen. nov., sp. nov., a New Prosthecate Aerobic Anoxygenic Phototroph Isolated from Lake Winnipegosis Region Salt Springs

A pink colored, rod-shaped, prosthecate, Gram-negative bacterial strain MS644^T was discovered in saline spring water near Lake Winnipegosis, Manitoba, Canada. It produces bacteriochlorophyll <i>a</i>, which is incorporated into its reaction center and light harvesting I complex. Alongside no anaerobic or photoautotrophic growth, these features support its designation as an aerobic anoxygenic phototroph (AAP). Unlike most AAP, the photosynthetic apparatus is produced in significantly greater amounts compared to carotenoids. Sequence of the 16S rRNA gene identified relatedness to <i>Glycocaulis albus</i> (96.19%), <i>Glycocaulis alkaliphilus</i> (96.12%) and <i>Glycocaulis abyssi</i> (96.07%). The DNA G + C content was 66.01 mol %. Differences in salt tolerance and photosynthesis capability, alongside low average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization compared to other <i>Maricauaceae</i>, support the designation of the strain as a representative of a new genus. Therefore, we propose that strain MS644^T (=NCIMB 15625^T = DSM 121292^T) be classified as the type species of a new genus <i>Apolloniradiicaulis</i> in <i>Maricaulaceae</i> with the name <i>A. salifontis</i> gen. nov., sp. nov.