A Novel Carotenoid-Producing Bacterium, Paenibacillus aurantius sp. nov., Isolated from Korean Marine Environment.

The novel bacterial strain MBLB1776 T was isolated from marine mud in Uljin, the Republic of Korea. Cells were Gram-positive, spore-forming, non-motile, and non-flagellated rods. Growth was observed at a temperature range of 10-45 °C, pH range of 6.0-8.0, and NaCl concentrations of 0-4% ( w / v ). Phylogenetic analysis of the 16S rRNA gene sequence revealed that MBLB1776 T belonged to the genus Paenibacillus and was closely related to Paenibacillus cavernae C4-5 T (94.83% similarity). Anteiso-C 15:0 , iso-C 16:0 , C 16:0 , and iso-C 15:0 were the predominant fatty acids. Menaquinone 7 was identified as the major isoprenoid quinone. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Its whole genome was 6.3 Mb in size, with a G+C content of 55.8 mol%. Average nucleotide identity and in silico DNA-DNA hybridization values were below the species delineation threshold. Gene function analysis revealed the presence of a complete C 30 carotenoid biosynthetic pathway. Intriguingly, MBLB1776 T harbored carotenoid pigments, imparting an orange color to whole cells. Based on this comprehensive polyphasic taxonomy, the MBLB1776 T strain represents a novel species within the genus Paenibacillus , for which the name Paenibacillus aurantius sp. nov is proposed. The type strain was MBLB1776 T (=KCTC 43279 T = JCM 34220 T ). This is the first report of a carotenoid-producing Paenibacillus sp.