Description and genomic characterization of Mangrovibrevibacter kandeliae gen. nov. sp. nov., a novel carotenoid-producing endophytic bacterium isolated from branch of mangrove plants.

Two Gram-stain-negative, aerobic, motile and short-rod-shaped bacterial strains, designated CSK15Z-1 and MSK8Z-1, were isolated from branch of Kandelia candel and Rhizophora stylosa, respectively, collected from Shankou Mangrove Nature Reserve in Guangxi, China, and had the ability to produce carotenoid. The 16S rRNA gene sequence similarity, average nucleotide identity (ANI) values, amino acid identity (AAI) values, and the digital DNA-DNA hybridization (dDDH) values between the two strains indicated that they should be affiliated with the same species. The AAI values between the two strains and other related species in the family Aurantimonadaceae ranged between 61.0 and 66.6%. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the two strains belong to the family Aurantimonadaceae and were most closely related to Aurantimonas endophytica EGI 6500337 and Aureimonas glaciistagni PAMC 27157. Phylogenomic analysis based on genome sequences showed that the two strains formed a single and stable branch within the family Aurantimonadaceae. The major respiratory quinone was Q-10. The predominant fatty acids were Cω7c, C cycle ω8c and C. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, an unidentified aminolipid and an unidentified lipid. In accordance with the AAI values, phylogenomic and phylogenetic analysis, phenotypic and chemotaxonomic characteristics, and genomic characterization, strains CSK15Z-1 and MSK8Z-1 should be considered as a novel genus and species in the family Aurantimonadaceae, for which the name Mangrovibrevibacter kandeliae gen. nov. sp. nov. is proposed. The type strain is CSK15Z-1 (= MCCC 1K07183 = JCM 34923).