In-Depth Genome Characterization and Pan-Genome Analysis of Strain KMM 296, a Producer of Highly Active Alkaline Phosphatase; Proposal for the Reclassification of Cobetia litoralis and Cobetia pacifica as the Later Heterotypic Synonyms of Cobetia amphilecti and Cobetia marina , and Emended Description of the Species Cobetia amphilecti and Cobetia marina .

A strictly aerobic, Gram-stain-negative, rod-shaped, and motile bacterium, designated strain KMM 296, isolated from the coelomic fluid of the mussel Crenomytilus grayanus , was investigated in detail due to its ability to produce a highly active alkaline phosphatase CmAP of the structural family PhoA. A previous taxonomic study allocated the strain to the species Cobetia marina , a member of the family Halomonadaceae of the class Gammaproteobacteria . However, 16S rRNA gene sequencing showed KMM 296's relatedness to Cobetia amphilecti NRIC 0815 T . The isolate grew with 0.5-19% NaCl at 4-42 °C and hydrolyzed Tweens 20 and 40 and L-tyrosine. The DNA G+C content was 62.5 mol%. The prevalent fatty acids were C 18:1 ω7c, C 12:0 3-OH, C 18:1 ω7c, C 12:0 , and C 17:0 cyclo. The polar lipid profile was characterized by the presence of phosphatidylethanolamine, phosphatidylglycerol, phosphatidic acid, and also an unidentified aminolipid, phospholipid, and a few unidentified lipids. The major respiratory quinone was Q-8. According to phylogenomic and chemotaxonomic evidence, and the nearest neighbors, the strain KMM 296 represents a member of the species C. amphilecti . The genome-based analysis of C. amphilecti NRIC 0815 T and C. litoralis NRIC 0814 T showed their belonging to a single species. In addition, the high similarity between the C. pacifica NRIC 0813 T and C. marina LMG 2217 T genomes suggests their affiliation to one species. Based on the rules of priority, C. litoralis should be reclassified as a later heterotypic synonym of C. amphilecti , and C. pacifica is a later heterotypic synonym of C. marina . The emended descriptions of the species C. amphilecti and C. marina are also proposed.