No abstract

A novel marine Gram-stain-negative, non-spore-forming, motile, aerobic, coccoid or ovoid bacterium, designated as strain DSL-16 T , was isolated from a tidal flat sediment on the East China Sea and characterized phylogenetically and phenotypically. Optimal growth of the strain occurred at 35 C (range 4-40 C), at pH 6 (range 5-11) and with 4 % (w/v) NaCl (range 1-14 %). The nearest phylogenetic neighbour was Paracoccus seriniphilus DSM 14827 T (98.2 % 16S rRNA gene sequence similarity). The digital DNA-DNA hybridization value between strain DSL-16 T and P. seriniphilus DSM 14827 T was 19.5±2.2 %. The average nucleotide identity value between strain DSL-16 T and P. seriniphilus DSM 14827 T was 83.6 %. The sole respiratory ubiquinone was Q-10. The major polar lipids were phosphatidylmonomethylethanolamine (PME), phosphatidylglycerol (PG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), diphosphatidyglycerol (DPG) and glycolipid (GL). The predominant cellular fatty acids of strain DSL-16 T were C 18 : 1 !7c, C 18 : 0 and 11-methyl C 18 : 1 !7c. The G+C content of the genomic DNA was 64.5 mol%. The combined genotypic and phenotypic data indicated that strain DSL-16 T represents a novel species of the genus Paracoccus, for which the name Paracoccus sediminilitoris sp. nov. is proposed. The type strain is DSL-16 T (=KCTC 62644 T =MCCC 1K03534 T).

Magnetotactic bacteria (MTB) are a group of phylogenetically and morphologically diverse prokaryotes that have the capability of sensing Earth's magnetic field via nanocrystals of magnetic iron minerals. These crystals are enclosed within intracellular membranes or organelles known as magnetosomes and enable a sensing function known as magnetotaxis. Although MTB were discovered over half a century ago, the study of the magnetosome biogenesis and organization remains limited to a few cultured MTB strains. Here, we present an integrative genomic and phenomic analysis to investigate the genetic basis of magnetosome biomineralization in both cultured and uncultured strains from phylogenetically diverse MTB groups. The magnetosome gene contents/networks of strains are corelated to magnetic particle morphology and chain configuration. We propose a general model for gene networks that control/regulate magnetosome biogenesis and chain assembly in MTB systems.