Hong Cheng

Isolation and Complete Genome Sequence of Algibacter alginolytica sp. nov., a Novel Seaweed-Degrading Bacteroidetes Bacterium with Diverse Putative Polysaccharide Utilization Loci

ABSTRACT The members of the phylum Bacteroidetes are recognized as some of the most important specialists for the degradation of polysaccharides. However, in contrast to research on Bacteroidetes in the human gut, research on polysaccharide degradation by marine Bacteroidetes is still rare. The genus Algibacter belongs to the Flavobacteriaceae family of the Bacteroidetes, and most species in this genus are isolated from or near the habitat of algae, indicating a preference for the complex polysaccharides of algae. In this work, a novel brown-seaweed-degrading strain designated HZ22 was isolated from the surface of a brown seaweed (Laminaria japonica). On the basis of its physiological, chemotaxonomic, and genotypic characteristics, it is proposed that strain HZ22 represents a novel species in the genus Algibacter with the proposed name Algibacter alginolytica sp. nov. The genome of strain HZ22, the type strain of this species, harbors 3,371 coding sequences (CDSs) and 255 carbohydrate-active enzymes (CAZymes), including 104 glycoside hydrolases (GHs) and 18 polysaccharide lyases (PLs); this appears to be the highest proportion of CAZymes (∼7.5%) among the reported strains in the class Flavobacteria. Seventeen polysaccharide utilization loci (PUL) are predicted to be specific for marine polysaccharides, especially algal polysaccharides from red, green, and brown seaweeds. In particular, PUL N is predicted to be specific for alginate. Taking these findings together with the results of assays of crude alginate lyases, we prove that strain HZ22T can completely degrade alginate. This work reveals that strain HZ22T has good potential for the degradation of algal polysaccharides and that the structure and related mechanism of PUL in strain HZ22T are worth further research.

Complete genome sequence of a benzo[a]pyrene-degrading bacterium Altererythrobacter epoxidivorans CGMCC 1.7731T

Altererythrobacter epoxidivorans CGMCC 1.7731(T) is a Gram-negative bacterium isolated from marine sediments. It is able to utilize benzo[a]pyrene as sole carbon and energy source. Here, we describe the complete genome sequence and annotation of A. epoxidivorans CGMCC 1.7731(T). The genome has a size of 2,786,256 bp (61.50 mol% G+C content), which consists of 2773 coding genes, 43 tRNA genes and 3 rRNA genes. According to the genome information, strain A. epoxidivorans CGMCC 1.7731(T) encodes 22 genes related to degradation of benzo[a]pyrene. These genes may have potential in bioremediation of PAH-polluted environments.

Complete genome sequence of the heavy metal resistant bacterium Altererythrobacter atlanticus 26DY36T, isolated from deep-sea sediment of the North Atlantic Mid-ocean ridge

Altererythrobacter atlanticus 26DY36(T) (CGMCC 1.12411(T)=JCM 18865(T)) was isolated from the North Atlantic Mid-Ocean Ridge. The strain is resistant to heavy metals, such as Mn(2+) (200 mM), Co(2+) (2.0mM), Cu(2+) (1mM), Zn(2+) (1mM), Hg(2+) (0.1mM) and Cd(2+) (0.5mM). Here we describe the genome sequence and annotation, as well as the features of the organism. A. atlanticus 26DY36(T) harbors a chromosome (3,386,291 bp) and a circular plasmid (88,815 bp). The genome contains 3322 protein-coding genes (2483 with predicted functions), 47 tRNA genes and 6 rRNA genes. A. atlanticus 26DY36(T) encodes dozens of genes related to heavy metal resistance and has potential applications in the bioremediation of heavy metal-contaminated environments.

Identification and genomic characterization of a KPC-2-, NDM-1- and NDM-5-producing Klebsiella michiganensis isolate

11 Nicolas-Chanoine MH, Gruson C, Bialek-Davenet S et al. 10-Fold increase (2006-11) in the rate of healthy subjects with extended-spectrum b-lactamase-producing Escherichia coli faecal carriage in a Parisian check-up centre. J Antimicrob Chemother 2013; 68: 562–8. 12 Guenther S, Aschenbrenner K, Stamm I et al. Comparable high rates of extended-spectrum-b-lactamase-producing Escherichia coli in birds of prey from Germany and Mongolia. PLoS One 2012; 7: e53039.

Henriciella pelagia sp. nov., isolated from seawater

Strain LA220T, isolated from seawater of the Eastern Pacific Ocean, was subjected to a polyphasic taxonomic study. Cells of the strain were Gram-stain-negative, aerobic, motile and short rod-shaped. On the basis of 16S rRNA gene sequence analysis, strain LA220T showed high similarity to Henriciella litoralis SD10T (98.5 %), Henriciella marina DSM 19595T (98.3 %) and Henriciellaaquimarina P38T (97.5 %), and exhibited less than 97.0 % 16S rRNA gene sequence similarity with respect to the type strains of other Hyphomonadaceae species. Phylogenetic analyses revealed that strain LA220T fell within the cluster of the genus Henriciella. The average nucleotide identity and in silico DNA-DNA hybridization values between strain LA220T and the type strains of Henriciella species were 74.8-76.8 and 18.4-20.8 %, respectively. The sole respiratory quinone was ubiquinone-10 (Q-10). The principal fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The major polar lipids were three unidentified glycolipids. The DNA G+C content was 59.9 mol%. Phylogenetic distinctiveness, chemotaxonomic differences and phenotypic properties revealed that strain LA220T could be differentiated from recognized Henriciella species. Therefore, strain LA220T is considered to represent a novel species of the genus Henriciella, for which the name Henriciella pelagia sp. nov. (type strain LA220T=CGMCC 1.15928T=KCTC 52577T) is proposed.

Draft Genome Sequence of Altererythrobacter marensis DSM 21428T, Isolated from Seawater

ABSTRACT Altererythrobacter marensis DSM 21428T was isolated from seawater collected around Mara Island, South Korea. The genomic characteristics of this strain support its potential for alkane-related compound degradation. A. marensis DSM 21428T has potential applications in bioremediation projects concerning offshore petroleum spill prevention and response.

Complete genome sequence of astaxanthin-producing bacterium Altererythrobacter ishigakiensis NBRC 107699

Altererythrobacter ishigakiensis NBRC 107699 was isolated from marine sediment collected from a site on the coast of Ishigaki Island, Japan and deposited to the NITE Biological Resource Center. This strain is able to produce astaxanthin, which can be used as a food supplement. Here we describe the genome sequence and annotation, as well as the features of the organism. The genome of strain NBRC 107699 comprises 2,673,978bp and contains 2618 protein-coding genes (1966 with predicted functions), 42 tRNA genes and 3 rRNA genes. A. ishigakiensis NBRC 107699T encodes fifteen genes related to astaxanthin production, revealing its potential application in biotechnological industry. The genome sequence of A. ishigakiensis NBRC 107699 now provides the fundamental information for future studies.

Croceicoccus pelagius sp. nov. and Croceicoccus mobilis sp. nov., isolated from marine environments

Strain Ery9T, isolated from surface seawater of the Atlantic Ocean, and strain Ery22T, isolated from deep-sea sediment of the Indian Ocean, were subjected to a taxonomic study using a polyphasic approach. Cells of the two strains were Gram-stain-negative, aerobic and rod-shaped. They produced yellow pigments and lacked bacteriochlorophyll a. On the basis of 16S rRNA gene sequence analysis, strain Ery9T was closely related to Croceicoccus naphthovorans PQ-2T (with 16S rRNA gene sequence similarity of 97.7 %), and strain Ery22T was closely related to Croceicoccusmarinus E4A9T (98.3 %). The 16S rRNA gene sequence similarity between strain Ery9T and strain Ery22T was 96.6 %. Phylogenetic analyses revealed that strains Ery9T and Ery22T fell within the cluster of the genus Croceicoccus and represented two independent lineages. The average nucleotide identity (ANI) values and the genome-to-genome distances between strains Ery9T and Ery22T and the type strains of species of the genus Croceicoccus with validly published names were 73.7-78.4 % and 20.1-22.3 %, respectively. The major respiratory quinone of the two isolates was ubiquinone-10 (Q-10). The DNA G+C contents of strains Ery9T and Ery22T were 62.8 and 62.5 mol%, respectively. Differential phylogenetic distinctiveness and chemotaxonomic differences, together with phenotypic properties, revealed that strains Ery9T and Ery22T could be differentiated from their closely related species. Therefore, it is concluded that strains Ery9T and Ery22T represent two novel species of the genus Croceicoccus, for which the names Croceicoccus pelagius sp. nov. (type strain Ery9T=CGMCC 1.15358T=DSM 101479T) and Croceicoccus mobilis sp. nov. (type strain Ery22T=CGMCC 1.15360T=DSM 101481T), are proposed.

Draft Genome Sequence of Altererythrobacter troitsensis JCM 17037, Isolated from the Sea Urchin Strongylocentrotus intermedius

ABSTRACT The habitats of the genus Altererythrobacter are various, including marine sediment, seawater, rhizosphere of wild rice, desert sand, etc. The genome of the type strain of Altererythrobacter troitsensis JCM 17037, isolated from sea urchin, was sequenced. This study would not only facilitate the understanding of the physiology, adaptation, and evolution of the Altererythrobacter species, but also provide a good resource for the study of synthesis of astaxanthin, since several enzymes involved in the production of astaxanthin were predicted.

Biochemical and genetic characterization of a novel metallo-β-lactamase from marine bacterium Erythrobacter litoralis HTCC 2594

Metallo-β-lactamases (MBLs) are a group of enzymes that can inactivate most commonly used β-lactam-based antibiotics. Among MBLs, New Delhi metallo-β-lactamase-1 (NDM-1) constitutes an urgent threat to public health as evidenced by its success in rapidly disseminating worldwide since its first discovery. Here we report the biochemical and genetic characteristics of a novel MBL, ElBla2, from the marine bacterium Erythrobacter litoralis HTCC 2594. This enzyme has a higher amino acid sequence similarity to NDM-1 (56%) than any previously reported MBL. Enzymatic assays and secondary structure alignment also confirmed the high similarity between these two enzymes. Whole genome comparison of four Erythrobacter species showed that genes located upstream and downstream of elbla2 were highly conserved, which may indicate that elbla2 was lost during evolution. Furthermore, we predicted two prophages, 13 genomic islands and 25 open reading frames related to insertion sequences in the genome of E. litoralis HTCC 2594. However, unlike NDM-1, the chromosome encoded ElBla2 did not locate in or near these mobile genetic elements, indicating that it cannot transfer between strains. Finally, following our phylogenetic analysis, we suggest a reclassification of E. litoralis HTCC 2594 as a novel species: Erythrobacter sp. HTCC 2594.