Complete Genome Sequence of Chryseobacterium sp. Strain StRB126, an N-Acylhomoserine Lactone-Degrading Bacterium Isolated from Potato Root

Phylogenetic insights into the diversity of Chryseobacterium species

The genus Chryseobacterium was formally established in 1994 and contains 112 species with validly published names. Most of these species are yellow or orange coloured, and contain a flexirubin-type pigment. The genomes of 83 of these 112 species have been sequenced in view of their importance in clinical microbiology and potential applications in biotechnology. The National Center for Biotechnology Information taxonomy browser lists 1415 strains as members of the genus Chryseobacterium, of which the genomes of 94 strains have been sequenced. In this study, by comparing the 16S rDNA and the deduced proteome sequences, at least 20 of these strains have been proposed to represent novel species of the genus Chryseobacterium. Furthermore, a yellow-coloured bacterium isolated from dry soil in the USA (and identified as Flavobacterium sp. strain B-14859) has also been reconciled as a novel member of the genus Chryseobacterium based on the analysis of 16S rDNA sequences and the presence of flexirubin. Yet another bacterium (isolated from a water sample collected in the Western Ghats of India and identified as Chryseobacterium sp. strain WG4) was also found to represent a novel species. These proposals need to be validated using polyphasic taxonomic approaches.

Genome assembly of Chryseobacterium sp. strain IHBB 10212 from glacier top-surface soil in the Indian trans-Himalayas with potential for hydrolytic enzymes

The cold-active esterases are gaining importance due to their catalytic activities finding applications in chemical industry, food processes and detergent industry as additives, and organic synthesis of unstable compounds as catalysts. In the present study, the complete genome sequence of 4,843,645 bp with an average 34.08% G + C content and 4260 protein-coding genes are reported for the low temperature-active esterase-producing novel strain of Chrysobacterium isolated from the top-surface soil of a glacier in the cold deserts of the Indian trans-Himalayas. The genome contained two plasmids of 16,553 and 11,450 bp with 40.54 and 40.37% G + C contents, respectively. Several genes encoding the hydrolysis of ester linkages of triglycerides into fatty acids and glycerol were predicted in the genome. The annotation also predicted the genes encoding proteases, lipases, amylases, β-glucosidases, endoglucanases and xylanases involved in biotechnological processes. The complete genome sequence of Chryseobacterium sp. strain IHBB 10212 and two plasmids have been deposited vide accession numbers CP015199, CP015200 and CP015201 at DDBJ/EMBL/GenBank.

Draft Genome Sequence of Chryseobacterium sp. JV274 Isolated from Maize Rhizosphere

We report the draft genome sequence of Chryseobacterium sp. JV274. This strain was isolated from the rhizosphere of maize during a greenhouse experiment. JV274 harbors genes involved in flexirubin production (darA and darB genes), bacterial competition (type VI secretion system), and gliding (bacterial motility; type IX secretion system).

Type B Chloramphenicol Acetyltransferases Are Responsible for Chloramphenicol Resistance in Riemerella anatipestifer, China

Riemerella anatipestifer causes serositis and septicaemia in domestic ducks, geese, and turkeys. Traditionally, the antibiotics were used to treat this disease. Currently, our understanding of R. anatipestifer susceptibility to chloramphenicol and the underlying resistance mechanism is limited. In this study, the cat gene was identified in 69/192 (36%) R. anatipestifer isolated from different regions in China, including R. anatipestifer CH-2 that has been sequenced in previous study. Sequence analysis suggested that there are two copies of cat gene in this strain. Only both two copies of the cat mutant strain showed a significant decrease in resistance to chloramphenicol, exhibiting 4 μg/ml in the minimum inhibitory concentration for this antibiotic, but not for the single cat gene deletion strains. Functional analysis of the cat gene via expression in Escherichia coli BL21 (DE3) cells and in vitro site-directed mutagenesis indicated that His79 is the main catalytic residue of CAT in R. anatipestifer. These results suggested that chloramphenicol resistance of R. anatipestifer CH-2 is mediated by the cat genes. Finally, homology analysis of types A and B CATs indicate that R. anatipestifer comprises type B3 CATs.