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Rheinheimera pacifica sp. nov., a novel halotolerant bacterium isolated from deep sea water of the Pacific

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This study was undertaken to survey culturable heterotrophic bacteria associated with the marine ark shell Anadara broughtoni inhabiting in the Sea of Japan, and to test isolates for their antimicrobial, hemolytic and surface activities with an emphasis on low-molecular-weight metabolites search. A total of 149 strains were isolated and identified phenotypically. A total of 27 strains were selected to be investigated phylogenetically by 165 rRNA gene sequence analysis. The most bacteria were affiliated with members of the Gammaproteobacteria and Alphaproteobacteria, and Less with Firmicutes, Actinobacteria, and Cytophaga-Flavobacterium-Bacteroides (CFB) group. The isolates capable of hemolysis were numerically abundant in the genera Pseudoalteromonas, Aeromonas and Bacillus. The six Gram-positive isolates belonging to the genera Bacillus, Paenibacillus and Saccharothrix and two Gram-negative strains related to Pseudomonas and Sphingomonas, possessed antimicrobial activity against indicator strains and to each other. Antimicrobial, hemolytic and surface activities were revealed in butanot extracts of cells or cell-free supernatant of six active strains. This points to availability of active low-molecular-weight metabolites. Substances with hemolytic and surface activities were isolated from strain Bacillus pumilus An 112 and characterized as cyclic depsipeptides with molecular masses 1021, 1035, 1049, 1063 and 1077 Da. The recovery of strains producing antimicrobial and surface-active substances suggests that microorganisms associated with the marine bivalve are potential source of bioactive metabolites.

Two Gram-negative, non-fermentative, non-denitrifying, non-pigmented, rod-shaped bacteria that were motile by means of polar flagella, designated strains KMM 330T and KMM 331, were isolated from a deep-sea sponge specimen and subjected to a polyphasic taxonomic study.

An aerobic, Gram-negative bacterium, strain KMM 329 T , was isolated from a deep-sea sponge specimen from the Philippine Sea and subjected to a polyphasic taxonomic investigation. Comparative 16S rRNA gene sequence analysis showed that strain KMM 329 T clustered with the species of the genus Lysobacter. The highest level of 16S rRNA gene sequence similarity (97.0 %) was found with respect to Lysobacter concretionis KCTC 12205 T ; lower values (96.4-95.2 %) were obtained with respect to the other recognized Lysobacter species. The value for DNA-DNA relatedness between strain KMM 329 T and L. concretionis KCTC 12205 T was 47 %. Branched fatty acids 16 : 0 iso, 15 : 0 iso, 11 : 0 iso 3-OH and 17 : 1 iso were found to be predominant. Strain KMM 329 T had a DNA G+C content of 69.0 mol%. On the basis of the phenotypic, chemotaxonomic, DNA-DNA hybridization and phylogenetic data, strain KMM 329 T represents a novel species of the genus Lysobacter, for which the name Lysobacter spongiicola sp. nov. is proposed. The type strain is KMM 329 T (5NRIC 0728 T 5JCM 14760 T ).

Marinomonas primoryensis sp. nov., a novel psychrophile isolated from coastal sea-ice in the Sea of Japan Two bacterial strains (KMM 3633 T and KMM 3634) were isolated from marine coastal sea-ice and characterized by using phenotypic and molecular methods. The isolates were aerobic, Gramnegative, psychrophilic, halophilic and motile by means of a single polar flagellum. The DNA G+C content was 45?3-45?6 mol%. The major cellular fatty acids were C 16 : 0 , C 16 : 1 v9c and C 18 : 1 v7c.Comparison of almost-complete 16S rDNA sequences demonstrated that the strains were phylogenetically closely related to each other (99?5 % sequence identity), and related to Marinomonas species (94?4-96?4 % identity). DNA-DNA reassociation between KMM 3633 T and KMM 3634 occurred at a level of 92 %. Based on phenotypic, chemotaxonomic and phylogenetic properties, the name Marinomonas primoryensis sp. nov. is proposed for strains KMM 3633 T and KMM 3634; the type strain is KMM 3633 T (=JCM 11775 T =NRIC 523 T ).

Alteromonas-like strains KMM 241T and KMM 642, isolated from marine invertebrate specimens, were investigated to clarify their taxonomic position. The novel isolates were aerobic, Gramnegative, motile, slightly halophilic and heterotrophic and hydrolysed polysaccharides. They did not hydrolyse urea, gelatin or casein and produced acid weakly from carbohydrates. The DNA G+C content ranged between 44?6 and 44?8 mol%. DNA-DNA similarity between the two strains was 71 %. Comparison of the 16S rRNA gene sequence of strain KMM 241 T revealed 94?5-94?8 % similarity to Glaciecola species. The novel strains shared several phenotypic and physiological properties with members of Glaciecola, but they differed in their lack of pigment production, their minimal and maximal growth temperatures and their ability to hydrolyse agar and carrageenan and in the utilization of organic compounds. On the basis of phenotypic and physiological characteristics as well as phylogenetic analysis, the isolates should be assigned to a novel species, Glaciecola mesophila sp. nov. The type strain is strain KMM 241 T (=DSM 15026 T ).