Rheinheimera longhuensis sp. nov., isolated from a slightly alkaline lake, and emended description of genus Rheinheimera Brettar et al. 2002.

The bacterial strain LH2-2(T) was isolated from freshwater of Longhu Lake, a slightly alkaline lake (pH 8.8) in north-east China. Cells of strain LH2-2(T) were Gram-staining-negative, non-spore-forming rods, 0.3-0.5 µm wide and 2.0-4.0 µm long. Cells were motile by means of a single polar flagellum. The strain was strictly aerobic and heterotrophic and oxidase- and catalase-positive. Growth occurred at 0-36 °C (optimum, 26-34 °C), pH 6.5-11 (optimum, pH 8.0-8.6) and in the presence of 0-2 % (w/v) NaCl (optimum, 1%). Strain LH2-2(T) contained Q-8 as the major respiratory quinone. The major fatty acids were summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH; 21.9%), C(17:1)ω8c (18.9%), C(18:1)ω7c (16.4%) and C(16:0) (12.7%) after growth on marine agar 2216. The DNA G+C content was 47 mol% (T(m)). The 16S rRNA gene and a conserved portion of the gyrB gene were sequenced and used for phylogenetic analyses. Phylogenetic trees based on 16S rRNA gene and gyrB sequences showed that strain LH2-2(T) was associated with the genus Rheinheimera and closely related to the type strains of Rheinheimera species, and showed the highest 16S rRNA gene sequence similarity to Rheinheimera pacifica KMM 1406(T) (97.4%), R. aquimaris SW-353(T) (97.1%) and R. chironomi K19414(T) (96.5%). The DNA-DNA relatedness of strain LH2-2(T) to R. pacifica NBRC 103167(T), R. aquimaris JCM 14331(T) and R. chironomi LMG 23818(T) was 39, 31 and 23%, respectively. Based on these results, it is concluded that strain LH2-2(T) represents a novel species of the genus Rheinheimera, for which the name Rheinheimera longhuensis sp. nov. is proposed. The type strain is LH2-2(T) ( = CGMCC 1.7003(T)  = NBRC 105632(T)). An emended description of the genus Rheinheimera is also provided.

Hydrocarboniphaga daqingensis sp. nov., isolated from a freshwater lake.

A Gram-negative bacterium, designated B2-9(T), was isolated from water of a slightly alkaline lake, Longhu Lake in Daqing, north-east China. Strain B2-9(T) was an aerobic rod, heterotrophic, catalase- and oxidase-positive and motile by means of a single polar flflagellum. The isolate grew well on n-alkanes C(9)-C(17) and weakly on C(6)-C(8), C(18) and C(19). Growth occurred at 10-37 °C (optimum 20-25 °C), at pH 5.5-9.5 (optimum pH 7.0) and with ≤1.0 % (w/v) NaCl. The major fatty acids were C(18 : 1)ω7c (41.4 %), summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c; 18.5 %) and C(16 : 0) (10.9 %). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain B2-9(T) belonged to the genus Hydrocarboniphaga of the class Gammaproteobacteria and shared 97.0 % 16S rRNA gene sequence similarity with Hydrocarboniphaga effusa AP103(T). DNA-DNA relatedness between strain B2-9(T) and H. effusa DSM 16095(T) was 24 %. The DNA G+C content of strain B2-9(T) was 66 mol%. Strain B2-9(T) is considered to represent a novel species of the genus Hydrocarboniphaga, for which the name Hydrocarboniphaga daqingensis sp. nov. is proposed. The type strain is B2-9(T) (=CGMCC 1.7049(T) =NBRC 104238(T)).

[Microbial diversity in scorpion intestine (Buthus martensii Karsch)].

Scorpion is an important officinal animal, and has a high nutritional value. In this study, the culture-independent and culture-dependent methods were used to investigate the microbial diversity in the scorpion's intestine. Results based on culture-independent method showed the bacteria to be related to alpha, beta, gamma-proteobacteria. Bacteria isolated by the culture-dependent method were high G + C, gram-positive bacteria. The genera Enterobacter, Serratia and Ochrobactrum were detected by both methods. To sum up the results from the two methods, the bacteria in scorpion intestine belong to 23 genera, which are Enterobacter, Serratia, Pseudomonas, Acinetobacter, Aeromonas, Citrobacter, Pedobacter, Delftia, Ralstonia, Ochrobactrum, Sphingomonas, Exiguobacterium, Gordonia, Nocardia, Rhodococcus, Janibacte, Kocuria, Micrococcus, Agromyces, Microbacterium, Agrococcus, Deinococcus, Ornithinimicrobium, and some uncultured species. The two methods have both advantages and shortcomings. However, when used simultaneously, they complement each other.

Catellibacterium aquatile sp. nov., isolated from fresh water, and emended description of the genus Catellibacterium Tanaka et al. 2004.

A Gram-negative, rod-shaped, non-pigmented, non-spore-forming bacterial strain that was motile by a single polar flagellum, designated A1-9(T), was isolated from Daqing reservoir in north-east China and its taxonomic position was studied using a polyphasic approach. Strain A1-9(T) was non-halophilic, strictly aerobic and heterotrophic and lacked carotenoids, internal membranes and genes for photosynthesis (puf genes). Strain A1-9(T) grew at 10-40 degrees C (optimum, 25-30 degrees C) and pH 5.5-9.0 (optimum, pH 6.0-6.5) and tolerated up to 1.0 % NaCl (w/v). Neither phototrophic nor fermentative growth was observed. The predominant ubiquinone was Q-10 and the major fatty acid was C(18 : 1) ω 7c (70 %). The DNA G+C content was 64.4 mol% (T(m)). Phylogenetic analyses based on the 16S rRNA gene sequence revealed that strain A1-9(T), together with Catellibacterium nectariphilum AST4(T), formed a deep line within the 'Rhodobacter clade' of the family Rhodobacteraceae and strain A1-9(T) showed 94.2 % 16S rRNA gene sequence similarity to C. nectariphilum AST4(T). On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain A1-9(T) is considered to represent a novel species of the genus Catellibacterium, for which the name Catellibacterium aquatile sp. nov. is proposed. The type strain is A1-9(T) (=CGMCC 1.7029(T) =NBRC 104254(T)).

Algoriphagus aquatilis sp. nov., isolated from a freshwater lake.

A Gram-negative, non-spore-forming, non-motile bacterium, strain A8-7(T), was isolated from fresh water of a slightly alkaline lake, Longhu Lake, in Daqing, north-east China, and its taxonomic position was studied by using a polyphasic approach. Strain A8-7(T) was aerobic, heterotrophic and positive for catalase and oxidase. It grew at 20-37 degrees C (optimum 30 degrees C) and pH 5.5-10.5 (optimum pH 7.5) and in the presence of 0-3 % (w/v) NaCl. It formed pink-pigmented, smooth and circular colonies, 1-2 mm in diameter, on R3A-V agar plates after incubation at 30 degrees C for 3 days. Cells of strain A8-7(T) were rods, 0.2-0.4 mum wide and 1.6-4.0 mum long. The major fatty acids (>10 %) were iso-C(15 : 0) (40.3 %) and summed feature 3 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH; 12.1 %). The menaquinone was MK-7. The DNA G+C content was 43 mol% (T(m)). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain A8-7(T) was phylogenetically related to members of the genus Algoriphagus, with sequence similarities of 92.6-95.2 %, the highest sequence similarity being to the sequence from Algoriphagus mannitolivorans IMSNU 14012(T). On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain A8-7(T) was considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus aquatilis sp. nov. is proposed. The type strain is A8-7(T) (=CGMCC 1.7030(T) =NBRC 104237(T)).