Phenylobacterium muchangponense sp. nov., isolated from beach soil, and emended description of the genus Phenylobacterium.

A Gram-staining-negative, non-motile, aerobic bacterium, designated strain A8T, was isolated from the beach soil of Muchangpo, Korea. Cells were rod-shaped (0.5-0.6×0.7-1.3 µm) and colonies were colourless, circular with entire edges and had a glistening surface. The isolate grew optimally at 25-35 °C and did not require NaCl for growth. Strain A8T could not assimilate acetate, DL-lactate, succinate, antipyrine or chloridazon, but weakly assimilated L-phenylalanine. Major fatty acids were summed feature 7 (comprising C18:1ω7c/ω9t/ω12t), C16:0 and summed feature 4 (comprising C16:1ω7c/ iso-C15:0 2-OH). The major isoprenoid quinone was ubiquinone-10 and the DNA G+C content was 72.3 mol%. Comparative 16S rRNA gene sequence studies showed that strain A8T belonged to the family Caulobacteraceae, class Alphaproteobacteria and was most closely related to type strains of members of the genus Phenylobacterium (95.7-97.1 % similarity). Signature nucleotides and phylogenetic analysis of the 16S rRNA gene sequence also suggested that strain A8T was affiliated with the genus Phenylobacterium. Low DNA-DNA relatedness values (3.0±1.8-11.5±3.2 %) indicated that strain A8T represented a distinct species that was separated from other type strains in the genus Phenylobacterium. On the basis of evidence from a polyphasic study, it is proposed that strain A8T (=KACC 15042T=LMG 25973T) represents the type strain of a novel species, Phenylobacterium muchangponense sp. nov. An emended description of the genus Phenylobacterium is also presented.

Shewanella arctica sp. nov., an iron-reducing bacterium isolated from Arctic marine sediment.

Two strains of dissimilatory iron-reducing bacteria, which could couple lactate oxidation to iron reduction for energy conservation, were isolated from Arctic marine sediment. The strains, IR12(T) and IR26, were both Gram-staining-negative, catalase- and oxidase-positive and facultative anaerobes. Their cells were rod-shaped and motile by means of a polar flagellum. Both strains grew in the presence of 0.5-3.5 % (w/v) NaCl, with an absolute requirement for Na(+). Both were psychrotolerant since they could grow at 4-28 °C but had an optimum growth temperature of 20 °C. Both grew at pH 4.5-9.0 (optimum, pH 7.5). The major fatty acids of strains IR12(T) and IR26 were summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c) and C(16 : 0). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains IR12(T) and IR26 belonged to the class Gammaproteobacteria and were most closely related to Shewanella vesiculosa M7(T), Shewanella livingstonensis NF22(T) and Shewanella frigidimarina ACAM 591(T) (with 98.5 and 98.8 %, 98.5 and 98.8 %, and 98.5 and 98.8 % sequence similarities, respectively). The genomic DNA G+C contents of strains IR12(T) and IR26 were 40.0 and 40.3 mol%, respectively. DNA-DNA relatedness data indicated that the two novel strains represented a single species that was distinct from S. vesiculosa M7(T), S. livingstonensis NF22(T) and S. frigidimarina ACAM 591(T). Based on the phylogenetic, phenotypic and DNA-DNA relatedness data, the two new strains represent a single novel species of the genus Shewanella, for which the name Shewanella arctica sp. nov. is proposed. The type strain is IR12(T) ( = KCTC 23109(T) = JCM 16723(T)).

Reichenbachiella faecimaris sp. nov., isolated from a tidal flat, and emended descriptions of the genus Reichenbachiella and Reichenbachiella agariperforans.

A taxonomic study was carried out on two bacterial strains, PCP11(T) and PCP104, isolated from a tidal flat of the Yellow Sea, Korea. Comparative 16S rRNA gene sequence studies showed that these strains belonged to the family Cytophagaceae, phylum Bacteroidetes. Strains PCP11(T) and PCP104 shared 99.4 % sequence similarity and were related most closely to Reichenbachiella agariperforans KMM 3525(T) (95.8 and 96.0 % sequence similarity, respectively). Members of the genera Fulvivirga, Roseivirga, Fabibacter and Marinoscillum were the next closest relatives of the new isolates, with sequence similarities ≤ 91 %. The two isolates were Gram-staining-negative, strictly aerobic, gliding bacteria. They grew in the presence of 1-5 % NaCl, at pH 5.5-8.5 and at 4-35 °C. Strains PCP11(T) and PCP104 shared a number of physiological and biochemical properties with Reichenbachiella agariperforans KMM 3525(T), but they differed from this strain in the hydrolysis of biopolymers and in the production of carotenoid and flexirubin-type pigments. Both strains possessed iso-C(15 : 0), summed feature 4 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH) and C(15 : 0) as major cellular fatty acids. The major respiratory quinone was menaquinone 7 (MK-7). The G+C contents of the genomic DNA of strains PCP11(T) and PCP104 were 39.6 and 41.9 mol%, respectively. On the basis of phenotypic data and phylogenetic inference, it is proposed that the two isolates represent a novel species, Reichenbachiella faecimaris sp. nov., with strain PCP11(T) ( = KACC 14523(T)  = JCM 16588(T)) as the type strain. Emended descriptions of the genus Reichenbachiella and Reichenbachiella agariperforans are also proposed.

Pseudoalteromonas donghaensis sp. nov., isolated from seawater.

A Gram-negative, rod-shaped, motile and aerobic bacterium, designated strain HJ51(T), was isolated from a seawater sample from the East Sea, near South Korea. The isolate grew slowly at 4 °C, was able to grow at 40 °C, required NaCl and grew optimally at pH 6.5-7.0. The G+C content of the genomic DNA was 41.8 mol%. The major fatty acids were summed feature 4 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH), C(16 : 0) and summed feature 7 (C(18 : 1)ω7c, C(18 : 1)ω9t and/or C(18 : 1)ω12t). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HJ51(T) belonged to the genus Pseudoalteromonas and had 91.7-98.9 % 16S rRNA gene sequence similarity with type strains of species of the genus Pseudoalteromonas. Strain HJ51(T) had 7.2 % DNA-DNA relatedness with Pseudoalteromonas mariniglutinosa DSM 15203(T) and 12.9 % with Pseudoalteromonas prydzensis DSM 14232(T). On the basis of the phenotypic, phylogenetic and genomic data, strain HJ51(T) represents a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas donghaensis sp. nov. is proposed. The type strain is HJ51(T) (=KCTC 22219(T)=LMG 24469(T)).

Flavobacterium chungbukense sp. nov., isolated from soil.

A yellow-pigmented, Gram-staining-negative, non-motile, strictly aerobic and rod-shaped bacterium, designated CS100(T), was isolated from soil in Chungbuk, Korea. Phylogenetic analysis and comparative studies based on the 16S rRNA gene sequence showed that strain CS100(T) belonged to the genus Flavobacterium in the family Flavobacteriaceae. Strain CS100(T) showed the highest sequence similarities to Flavobacterium glaciei JCM 13953(T) (97.6 %) and Flavobacterium johnsoniae KACC 11410(T) (97.1 %). Sequence similarity to other members of the genus Flavobacterium was 91.5-97.0 %. Growth occurred at 4-30 °C, at pH 5.0-9.0 and in the presence of 0-2 % (w/v) NaCl. Flexirubin-type pigments were produced. Menaquinone-6 (MK-6) was the major respiratory quinone and the major fatty acids were iso-C(15 : 0) (17.3 %), summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c, 15.5 %) and C(16 : 0) (11.8 %). The DNA G+C content was 36.4 mol%. Strain CS100(T) hydrolysed skimmed milk and gelatin, but not chitin or pectin, and showed oxidase and catalase activities. DNA-DNA relatedness was 3.0 % with F. glaciei JCM 13953(T) and 11.5 % with F. johnsoniae KACC 11410(T). On the basis of the evidence from this study, strain CS100(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium chungbukense sp. nov. is proposed. The type strain is CS100(T) ( = KACC 15048(T) = JCM 17386(T)).

Roseovarius halotolerans sp. nov., isolated from deep seawater.

A Gram-reaction-negative, non-motile, aerobic bacterium, designated HJ50(T), was isolated from deep seawater of the East Sea, South Korea. Cells were ovoid to rod-shaped (0.5-0.8x1.3-3.0 mum), often with unequal ends, suggesting a budding mode of reproduction. The strain had an absolute requirement for sea salts and tolerated up to 20 % (w/v) sea salts. Propionate, dl-lactate, 2-ketogluconate, 3-hydroxybutyrate and rhamnose were used as growth substrates, but not mannitol, salicin, 4-hydroxybenzoate or acetate. The major fatty acid was summed feature 7 (C(18 : 1)omega7c/omega9t/omega12t) and the DNA G+C content was 59.0+/-0.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that this strain was affiliated with the genus Roseovarius. Similarities between the 16S rRNA gene sequence of strain HJ50(T) (1430 nt) and those of type strains of members of the genus Roseovarius were 94.1-96.3 %. DNA-DNA relatedness values between strain HJ50(T) and the type strains of members of the genus Roseovarius were low (1.3-24.6 %). Physiological and biochemical differences support assignment of strain HJ50(T) to the genus Roseovarius as a representative of a novel species. The name Roseovarius halotolerans sp. nov. is proposed, with HJ50(T) (=KCTC 22224(T) =LMG 24468(T)) as the type strain.

Isolation and characterization of cold-adapted strains producing beta-galactosidase.

beta-Galactosidase is extensively employed in the manufacture of dairy products, including lactose-reduced milk. Here, we have isolated two gram-negative and rod-shaped coldadapted bacteria, BS 1 and HS 39. These strains were able to break down lactose at low temperatures. Although two isolates were found to grow well at 10 degrees , the BS 1 strain was unable to grow at 37 degrees . Another strain, HS-39, evidenced retarded growth at 37 degrees . The biochemical characteristics and the results of 16S rDNA sequencing identified the BS 1 isolate as Rahnella aquatilis, and showed that the HS 39 strain belonged to genus Buttiauxella. Whereas the R. aquatilis BS 1 strain generated maximal quantities of beta-galactosidase when incubated for 60 h at 10 degrees , Buttiauxella sp. HS-39 generated beta-galactosidase earlier, and at slightly lower levels, than R. aquatilis BS 1. The optimum temperature for beta-galactosidase was 30 degrees for R. aquatilis BS-1, and was 45 degrees for Buttiauxella sp. HS-39, thereby indicating that R. aquatilis BS-1 was able to generate a cold-adaptive enzyme. These two cold-adapted strains, and most notably the beta-galactosidase from each isolate, might prove useful in some biotechnological applications.