Dao-Feng Zhang

Enumeration of Vibrio parahaemolyticus in oyster tissues following artificial contamination and depuration

Aims:  To evaluate enumeration of Vibrio parahaemolyticus in oyster tissues following artificial contamination and depuration.

Nocardioides nanhaiensis sp. nov., an actinobacterium isolated from a marine sediment sample

A rod- to coccus-shaped, non-spore-forming actinobacterium, strain YIM M13091(T), was isolated from a marine sediment sample collected from the South China Sea and examined by a polyphasic approach to clarify its taxonomic position. This Gram-staining-positive, aerobic actinobacterium did not produce substrate mycelium and aerial hyphae, and no diffusible pigments were produced on the media tested. The optimum growth occurred at 30 °C, 1% (w/v) NaCl and pH 8.0. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Nocardioides, with low levels (≤96.2%) of sequence similarity with respect to Nocardioides kribbensis KSL-2(T) and other members of the genus Nocardioides. Whole-organism hydrolysates of the strain contained ll-2,6-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinone was MK-8(H4), with MK-8 in a minor amount. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, hydroxyphosphatidylinositol and phosphatidylcholine, were the main polar lipids detected, while iso-C(16 : 0) and C(18 : 1)ω9c were the major fatty acids. The G+C content of the genomic DNA was 68.5 mol%. Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the isolate represents a member of the genus Nocardioides, and the name Nocardioides nanhaiensis sp. nov. (Type strain YIM M13091(T) = JCM 18127(T) = CCTCC AA 2011020(T)) is proposed for the novel species.

Description of Streptomonospora sediminis sp. nov. and Streptomonospora nanhaiensis sp. nov., and reclassification of Nocardiopsis arabia Hozzein & Goodfellow 2008 as Streptomonospora arabica comb. nov. and emended description of the genus Streptomonospora.

Two actinomycete strains isolated from marine sediment samples, designated YIM M11335(T) (from the Indian Ocean) and 12A09(T) (from the South China Sea), were obtained and examined by a polyphasic approach. The two Gram-staining-positive, aerobic strains produced branched substrate mycelia and aerial hyphae that were not fragmented, and no diffusible pigment was produced on the media tested. At maturity, spore chains and single spores were formed on aerial hyphae and substrate mycelium, respectively. Whole-organism hydrolysates of both strains contained meso-diaminopimelic acid and the diagnostic sugars glucose and galactose. Their predominant menaquinones were MK-10(H4), MK-10(H6), MK-11(H4), MK-11(H6) and MK-11(H8) for strain YIM 11335(T) and MK-10(H4), MK-10(H6), MK-11(H4), MK-11(H6) and MK-11(H8) for strain 12A09(T). The polar lipids detected in the two strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phosphatidylcholine, an unknown phosphoglycolipid and several unknown glycolipids, phospholipids and polar lipids. The major fatty acids (>10%) were iso-C16 : 0 and C16:0 for strain YIM 11335(T) and iso-C16:0 for strain 12A09(T). The G+C contents of the genomic DNA of strains YIM 11335(T) and 12A09(T) were 70.7% and 74.4%, respectively. DNA-DNA hybridization relatedness values of these two isolates with the type strains Nocardiopsis arabia DSM 45083(T) and Streptomonospora halophila YIM 91355(T) supported the hypothesis they are representatives of two different species. Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the two isolates belong to the genus Streptomonospora of the family Nocardiopsaceae and that the type strain of N. arabia should be reclassified as a representative of Streptomonospora arabica comb. nov. The names proposed for the two novel species are Streptomonospora sediminis sp. nov. (type strain YIM M11335(T) = DSM 45723(T) = CCTCC AB 2012051(T)) and Streptomonospora nanhaiensis sp. nov. (type strain 12A09(T) = KCTC 29145(T) = CCTCC AB 2013140(T)), respectively. An emended description of the genus Streptomonospora is also proposed in the light of the new data.

Streptomyces bohaiensis sp. nov., a novel actinomycete isolated from Scomberomorus niphonius in the Bohai Sea.

A novel actinomycete strain, designated 11A07T, was isolated from young Scomberomorus niphonius in the Bohai Sea. Basic local alignment search tool analyses showed that this isolate had the highest 16S rRNA gene sequence similarity of 97.41% with Streptomyces rimosus subsp. paromomycinus DSM 41429T. Phylogenetic tree revealed that strain 11A07T formed a distinct lineage clustered with Streptomyces panacagri Gsoil 519T, Streptomyces sodiiphilus YIM 80305T and Streptomyces albus subsp. albus NRRL B-2365T having similarities of 97.30%, 97.10% and 96.83%, respectively. Multilocus sequence analysis further demonstrated that the new isolate was different from the selected representatives of Streptomyces as a separate phylogenetic line. Strain 11A07T produced straight or rectiflexibile spore chains with smooth surface, white aerial mycelia and brown diffusible pigments on international streptomyces project 2 medium. Maximum tolerated NaCl concentration for growth was 11.0%. Whole-cell sugars were mannose, ribose, glucose, galactose and xylose. The predominant menaquinones were MK-9(H2), MK-9(H4) and MK-9 (H6). The fatty-acid profile contained iso-C16:0, C18:0 10-methyl (tuberculostearic acid) and anteiso-C17:0 as the major compositions. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unknown phospholipid. The G+C content of the genomic DNA was 71.4 mol%. These morphological, phenotypic and chemotaxonomic properties showed that strain 11A07T could be readily distinguished from the most closely related members of the genus Streptomyces. Thus, based on the polyphasic taxonomic data, strain 11A07T (=JCM 19630T=CCTCC AA 2013020T=KCTC 29263T) represents a novel species within the genus Streptomyces, for which the name Streptomyces bohaiensis sp. nov. is proposed.

Pseudonocardia sediminis sp. nov., isolated from marine sediment.

A Gram-stain-positive, aerobic actinomycete, designated strain YIM M13141(T), was isolated from a marine sediment sample from the South China Sea, and its taxonomic position was determined using a polyphasic approach. The strain produced branched substrate mycelium and aerial hyphae, but no diffusible pigments were produced on the media tested. At maturity, substrate mycelium was fragmented and spore chains were formed on aerial hyphae and substrate mycelium. Optimum growth occurred at 28 °C, 1-3% (w/v) NaCl and pH 7.0. Comparative analysis of the 16S rRNA gene sequence showed that the isolate belongs to the genus Pseudonocardia, showing highest levels of similarity with respect to Pseudonocardia sichuanensis KLBMP 1115(T) (97.1%), Pseudonocardia tetrahydrofuranoxydans K1(T) (97.1%) and Pseudonocardia kunmingensis YIM 63158(T) (97.0%). Whole-organism hydrolysates of the strain contained meso-diaminopimelic acid and the sugars galactose, glucose, mannose and arabinose. The predominant menaquinone was MK-8(H4). The polar lipids detected were diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylmethylethanolamine, phosphatidylethanolamine, two unknown phosphoglycolipids and two glycolipids. The major fatty acid was iso-C16 : 0. The G+C content of the genomic DNA was 73.1 mol%. DNA-DNA relatedness with P. tetrahydrofuranoxydans DSM 44239(T) was 42.8 ± 3.5% (mean±sd). Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the isolate represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia sediminis sp. nov. is proposed. The type strain is YIM M13141(T) ( = DSM 45779(T) = JCM 18540(T)).

Actinophytocola sediminis sp. nov., an actinomycete isolated from a marine sediment

A novel actinomycete strain, designated YIM M13705(T), was isolated from a marine sediment sample of the South China Sea and its characteristics were determined by a polyphasic approach. The slowly growing, Gram-stain-positive, aerobic strain produced branched substrate mycelium and aerial hyphae, and no diffusible pigment was produced on the media tested. At maturity, spore chains were formed on aerial hyphae and substrate mycelium was not fragmented. Whole-cell hydrolysates of the strain contained meso-diaminopimelic acid and galactose, glucose, ribose and rhamnose. The predominant menaquinones were MK-9(H4) and MK-10(H2). The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol and ninhydrin-positive phosphoglycolipids. The major fatty acid was iso-C(16 : 0). The G+C content of the genomic DNA was 68.2 mol%. On the basis of 16S rRNA gene sequence, the strain was shown to be most closely related to species of the genus Actinophytocola. DNA-DNA hybridization relatedness values (<70%) of the isolate with its closest neighbour Actinophytocola xinjiangensis QAIII60(T) supported classification of the isolate as a representative of a novel species. On the basis of phylogenetic analysis, and phenotypic and genotypic data, it is concluded that the new isolate belongs to a novel species of the genus Actinophytocola, for which the name Actinophytocola sediminis sp. nov. (type strain YIM M13705(T) = DSM 45939(T) = BCRC 16956(T)) is proposed.

Haloactinopolyspora alkaliphila sp. nov., and emended description of the genus Haloactinopolyspora

A facultatively alkaliphilic actinomycete strain, designated EGI 80088(T), was isolated from a saline-alkali soil sample from Xinjiang province, north-west China, and subjected to a polyphasic taxonomic characterization. Strain EGI 80088(T) formed fragmented aerial hyphae and short spore chains, and rod-like spores aggregated at maturity. Whole-cell hydrolysates of the isolate contained ll-diaminopimelic acid as the diagnostic diamino acid, and glucosamine, mannose, galactose, glucose and rhamnose as the marker sugars. The major fatty acids identified (>5%) were anteiso-C(15 : 0), iso-C(15 : 0), summed feature 4 (iso-C(17 : 1)I/anteiso-C(17 : 1)B), iso-C(16 : 0) and anteiso-C(17 : 0). The predominant menaquinone was MK-9(H4). The G+C content of the genomic DNA of strain EGI 80088(T) was 70.6 mol%. EGI 80088(T) showed the highest 16S rRNA gene sequence similarity to its closest phylogenetic neighbour Haloactinopolyspora alba YIM 93246(T) (98.5%). The DNA-DNA relatedness value of the strain EGI 80088(T) and H. alba YIM 93246(T) was 59.3±5.2%. On the basis of morphological, chemotaxonomic and phylogenetic characteristics and DNA-DNA hybridization data, strain EGI 80088(T) represents a novel species of the genus Haloactinopolyspora, for which the name Haloactinopolyspora alkaliphila sp. nov. (type strain EGI 80088(T) = BCRC 16946(T) = JCM 19128(T)) is proposed. The description of the genus Haloactinopolyspora has also been emended.

Phylogenetic diversity of sulphate-reducing Desulfovibrio associated with three South China Sea sponges.

Marine sponges harbour dense and diverse micro‐organisms which includes sulphate‐reducing bacteria (SRB). SRB are known to play a key role in the cycling of marine elements. However, in contrast to carbon and nitrogen cycling bacteria, SRB associated with marine sponges are largely unexplored. In this study, we explored the phylogenetic diversity of the SRB associated with three shallow‐water sponges Arenosclera heroni, Dysidea arenaria and Astrosclera willeyana from the South China Sea by cloning‐and‐sequencing approach of SRB 16S rRNA gene with specific primers. The results showed that SRB associated with sponges mainly belonged to the genus Desulfovibrio in the class Deltaproteobacteria, i.e. a total of 14 Desulfovibrio‐related OTUs were obtained from three sponges. The exception is identical OTUs from different sponges. Each sponge species harboured a unique set of Desulfovibrio OTUs, with only a few shared OTUs observed between species, suggesting different species of Desulfovibrio in different species of sponges. Meanwhile, some Desulfovibrio OTUs had a low similarity (<97%) with related sequences in GenBank and phylogenetic analysis indicating novel Desulfovibrio symbionts in sponges. The results contribute to the overall understanding of the phylogenetic diversity of SRB associated with sponges.

Mariniluteicoccus flavus gen. nov., sp. nov., a new member of the family Propionibacteriaceae, isolated from a deep-sea sediment

A Gram-staining-positive, aerobic, non-motile, irregular coccus, designated strain YIM M13146(T), was isolated from a sediment sample collected from the South China Sea at a depth of 2439 m, and its taxonomic position was determined by a polyphasic approach. Optimal growth of the strain was observed at 30 °C (range 5-40 °C), pH 7.0 (pH 6.0-9.0) and 0-1% NaCl (0-6%, w/v) on/in tryptic soy agar/broth. Strain YIM M13146(T) had the major cellular fatty acid anteiso-C15:0, the predominant respiratory menaquinone MK-9(H4), peptidoglycan type A3γ (ll-DAP-Gly) containing alanine, glycine, glutamic acid and ll-diaminopimelic acid (ll-DAP) and the polar lipids phosphatidylcholine, diphosphatidylglycerol, one unknown phospholipid and several glycolipids. The G+C content of the DNA was 67.2 mol%. Phenotypic and chemotaxonomic characteristics together with 16S rRNA gene sequence analyses showed that strain YIM M13146(T) was distinct from its close phylogenetic relatives in the genera Propioniferax and Granulicoccus of the family Propionibacteriaceae. Hence, a new genus and species, Mariniluteicoccus flavus gen. nov., sp. nov., is proposed. The type strain of Mariniluteicoccus flavus is YIM M13146(T) ( = DSM 25892(T) = CCTCC AB 2012055(T)).

Nocardiopsis oceani sp. nov. and Nocardiopsis nanhaiensis sp. nov., actinomycetes isolated from marine sediment of the South China Sea

Two actinomycete strains, designated 10A08AT and 10A08BT, were isolated from marine sediment samples of the South China Sea and their taxonomic positions were determined by a polyphasic approach. The two Gram-stain-positive, aerobic strains produced branched substrate mycelium and aerial hyphae, and no diffusible pigment was produced in the media tested. At maturity, spore chains were formed on aerial hyphae and all mycelium fragmented with age. Whole-cell hydrolysates of both strains contained meso-diaminopimelic acid and no diagnostic sugars. Their predominant menaquinones (>10 %) were MK-9(H4), MK-9(H6) and MK-10(H6) for strain 10A08AT and MK-9(H4), MK-9(H6), MK-10(H4) and MK-10(H6) for strain 10A08BT. The polar lipids detected from the two strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and unknown phosphoglycolipids and phospholipids. The major fatty acids (>10 %) of both strains were iso-C16 : 0 and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The genomic DNA G+C contents of strains 10A08AT and 10A08BT were 70.9 and 71.6 mol%, respectively. On the basis of 16S rRNA gene sequence similarities, the two strains were shown to be most closely related to species of the genus Nocardiopsis. DNA–DNA hybridization relatedness values of < 70 % between these two isolates and their closest neighbour, Nocardiopsis terrae YIM 90022T, and between the two strains supported the conclusion that they represent two novel species. Based on phylogenetic analysis and phenotypic and genotypic data, it is concluded that the two isolates belong to the genus Nocardiopsis, and the names Nocardiopsis oceani sp. nov. (type strain 10A08AT = DSM 45931T = BCRC 16951T) and Nocardiopsis nanhaiensis sp. nov. (type strain 10A08BT = CGMCC 47227T = BCRC 16952T) are proposed.