A new antibacterial amino phenyl pyrrolidone derivative from a novel marine gliding bacterium Rapidithrix thailandica.

A recently described marine gliding bacterium Rapidithrix thailandica strain TISTR 1741 was isolated from biofilm specimen collected from the Andaman Sea in Thailand. Four liters fermentation broth of R. thailandica TISTR 1741 cultivated in VY/2 medium were extracted with methanol to yield a novel amino phenyl pyrrolidone derivative compound (1) with antibacterial activities. The chemical structure and physico-chemical properties of 1 were investigated by spectrometry techniques. Compound 1 exhibited selective inhibition against vancomycin-resistant Enterococcus faecalis (VRE) with the MIC of 5.97 mM.

Antimutagenicity and antioxidative DNA damage properties of oligomeric proanthocyanidins from Thai grape seeds in TK6 cells.

Oligomeric proanthocyanidins (OPCs) are found mostly in red grape seeds. Many publications have reported that OPCs possess an excellent anti-oxidant effects. Since it could against cellular damage from reactive oxygen species (ROS) led to reduce the risk of chronic disease and cancers. We carried out this study on the Thai OPCs to evaluate the mutagenicity/ anti-mutagenicity and anti-oxidative DNA damage effects in TK6 cells by micronucleus (MN) and comet assays. In the MN assay, OPCs-treatment of TK6 cells at concentrations ranging from 10-200 ?g/ml (4 and 24 h) did not cause micronucleus induction over the negative control group but revealed a significant reduction the micronucleus frequencies against the known mutagen (mitomycin C). In the comet assay, OPCs-treated TK6 cells at concentrations of 100, 250, 500, and 1,000 ?g/ml could inhibit DNA damage induced by H(2)O(2) as indicated by 18.7, 36.4, 30.6, and 60.1%, respectively. Our results suggest that OPCs possess the anti-mutagenic and anti-oxidative DNA damage effects in TK6 cells under the conditions of this assay.

Diversity of marine gliding bacteria in Thailand and their cytotoxicity

Eighty-four marine gliding bacteria were isolated from specimens collected in the Gulf of Thailand and the Andaman Sea. All exhibited gliding motility and swarm colonies on cultivation plates and they were purified by subculturing and micromanipulator techniques. Their 16S rRNA genes were amplified by the polymerase chain reaction (PCR) technique. The phylogenetic analysis indicated that the represented isolates can be separated into six different clads (gr 1 - gr 6) within the Cytophaga-Flavobacterium-Bacteriodes (CFB) group. Group 1 formed a remote linear, with only 90 percent sequence similarity, from Flavobacteriaceae bacterium which indicated a potentially novel taxonomic group. Groups 2 and 3 were identified as the recently proposed Tenacibaculum mesophilum and Fulvivirga kasyanovii respectively. Groups 4, 5 and 6, consisting of the largest number of the members, were identified as Rapidithrix thailandica, Aureispira marina and Aureispira maritima respectively. The isolates were cultivated in four different cultivation media (Vy/2, RL 1, CY and SK) and the crude extracts were submitted to screen cytotoxicity using a sulphorodamine B (SRB) assay. The results from cytotoxic screening showed that groups 2, 4 and 6 were capable of producing the cytotoxic metabolites against selected human cell lines (breast adenocarcinoma (MCF-7), colon cancer (HT-29), cervical cancer (HeLa) and oral cancer (KB)). However, groups 1, 3 and 5 did not produce metabolites with cytotoxicity when cultivated in the same cultivation media as the previous groups. CY medium was the only cultivation medium which could yield the cytotoxic metabolites against MCF-7.

Rapidithrix thailandica gen. nov., sp. nov., a marine gliding bacterium isolated from samples collected from the Andaman sea, along the southern coastline of Thailand.

The taxonomic positions of three strains of marine gliding bacteria, TISTR 1736, TISTR 1741 and TISTR 1750(T), isolated from the southern coastline of Thailand were evaluated by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the three isolates formed a distinct lineage within the family 'Flammeovirgaceae', phylum Bacteroidetes, and were related to the genus Flexithrix. The DNA G+C contents of the isolates were in the range 40-43 mol%. The major respiratory quinone was MK-7. The major cellular fatty acids were 16 : 1omega5c (cis-5-hexadecenoic acid) and 15 : 0 (pentadecanoic acid). The major hydroxyl fatty acids were 3-OH 17 : 0 (3-hydroxyheptadecanoic acid), 3-OH 15 : 0 (3-hydroxypentadecanoic acid) and 3-OH 16 : 0 (3-hydroxyhexadecanoic acid). On the basis of phenotypic, chemotaxonomic, genotypic and phylogenetic data, these marine bacteria are considered to represent a novel species of a new genus, for which the name Rapidithrix thailandica gen. nov., sp. nov. is proposed. The type strain of Rapidithrix thailandica is TISTR 1750(T) (=IAM 15448(T)).

Aureispira maritima sp. nov., isolated from marine barnacle debris.

A novel gliding marine bacterium (strain 59SA(T)) was isolated from marine barnacle debris. A phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate formed a distinct lineage within the genus Aureispira in the family 'Saprospiraceae'. The DNA G+C content of strain 59SA(T) was 38.7 mol%, the major respiratory quinone was MK-7 and the predominant cellular fatty acids were 20 : 4omega6c and 16 : 0. On the basis of the data from DNA-DNA hybridization, physiological and chemotaxonomic analyses and 16S rRNA gene sequence comparisons, strain 59SA(T) represents a novel species of the genus Aureispira, for which the name Aureispira maritima sp. nov. is proposed. The type strain is 59SA(T) (=IAM 15439(T)=TISTR 1726(T)).

Aureispira marina gen. nov., sp. nov., a gliding, arachidonic acid-containing bacterium isolated from the southern coastline of Thailand.

Three strains of gliding bacteria, 24(T), 62 and 71, isolated from a marine sponge and algae from the southern coastline of Thailand, were studied using a polyphasic approach to clarify their taxonomic positions. A phylogenetic analysis based on 16S rRNA gene sequences showed that the three isolates formed a distinct lineage within the family 'Saprospiraceae' of the phylum Bacteroidetes and were related to members of the genus Saprospira. The G+C contents of the isolates were in the range 38-39 mol%. The major respiratory quinone was MK-7. The predominant cellular fatty acids were 20 : 4omega6c (arachidonic acid), 16 : 0 and iso-17 : 0. On the basis of morphological, physiological and chemotaxonomic characteristics, together with DNA-DNA hybridization data and 16S rRNA gene sequences, the isolates represent a novel species of a novel genus, for which the name Aureispira marina gen. nov., sp. nov. is proposed. The type strain of Aureispira marina is 24(T) (=IAM 15389(T)=TISTR 1719(T)).

Kockovaella barringtoniae sp. nov., a new basidiomycetous yeast species isolated from a plant leaf collected in a tropical rain forest in Thailand.

One yeast strain characterized by the proliferation of non-ballistosporous stalked conidia, budding cells and ballistoconidia, the presence of xylose in whole-cell hydrolysates, the presence of Q-10 as the major ubiquinone isoprenologue, the inability to ferment sugars and positive diazonium blue B (DBB) and urease reactions was isolated from a plant sample collected in a tropical rain forest in Thailand. The isolate clustered with Kockovaella species in the 18S rDNA-based tree. On the basis of the morphological, biochemical and molecular phylogenetic characteristics, the isolate was assigned to the genus Kockovaella. DNA complementarity experiments showed that the isolate was genetically distinct from known species of the genus Kockovaella. The isolate is described as Kockovaella barringtoniae sp. nov. The type strain is strain TY-278T (= JCM 10998T = TISTR 5770T).

Tistrella mobilis gen nov, sp nov, a novel polyhydroxyalkanoate-producing bacterium belonging to alpha-Proteobacteria.

Strain IAM 14872, isolated from wastewater in Thailand, is capable of producing polyhydroxyalkanoate. This bacterium is Gram-negative, rod-shaped, strictly aerobic and highly motile with a single polar flagellum. Both oxidase and catalase activities are positive. The G+C content of DNA is 67.5% and Q-10 is the major quinone. The major cellular fatty acids are C(18:1)omega7c, 2-OH C(18:0) and 3-OH C(14:0). On the basis of the 16S rDNA sequence analysis and phenotypic properties, it is proposed that the strain IAM 14872 be classified in a new genus as Tistrella mobilis gen. nov., sp. nov. The type strain is IAM 14872(T) (=TISTR 1108(T)).