Genome analysis of Salinimicrobium sp. 3283s, a deep-sea bacterium isolated from the sediments of South China Sea, China

Salinimicrobium sp. 3283s is an aerobic, golden-yellow pigment-producing, Flavobacteriaceae bacterium isolated from the sediments at the depth of 1751 m in the South China Sea. In this study, we present the complete genome sequence of strain 3283s, which only have a single circular chromosome comprising 3,702,683 bp with 41.41% G + C content and no circular plasmid. In total, 3257 protein coding genes, 45 tRNA, 9 rRNA, and 13 sRNA genes were obtained. In terms of the function of gene annotation, strain 3283s was more different from Salinimicrobium oceani J15B91, which was isolated from the South China Sea at a similar depth, and more similar to a Mariana Trench-derived strain Salinimicrobium profundisediminis MT39, which was closer in phylogenetic taxonomic status, suggesting that strain 3283s possesses a stronger potential to adapt to the deep-sea environment. Furthermore, the high- pressure simulations also confirmed that strain 3283s can grow in both 30 MPa and 60 MPa hydrostatic pressure environments, and that it grows better in 30 MPa hydrostatic pressure environments than in 60 MPa hydrostatic pressure environments. In addition, we found a large number of genes in strain 3283s that can promote better adaptation of the bacteria to the low oxygen and high hydrostatic pressure (HHP) environment of the deep sea, such as biosynthetic enzymes of antioxidant pigments, genes encoding cytochromes with enhanced affinity for oxygen, proteins for adaptation to HHP, and genes encoding TonB-dependent transporters in the absence of flagella.