Mikhail V. Vysotskii

Phenotypic diversity of Pseudoalteromonas citrea from different marine habitats and emendation of the description

Four strains of marine, aerobic, agar-decomposing bacteria with one polar flagellum and with DNA G + C contents of 38.9-40.2 mol% were isolated from the Far-Eastern mussels Crenomytilus grayanus and Patinopecten yessoensis. These four strains were identified as Pseudoalteromonas; however, they were phenotypically different from species described previously according to carbon compound utilization tests and the BIOLOG identification system. High agar-decomposing activity was found in two strains, in one of which agarase, alpha-galactosidase, pustulanase and laminarinase had been detected. The level of DNA homology of three of the strains was 70-100%. The fourth isolate was genetically less related to the others (67% DNA relatedness) and phenotypically was more distant from other members of this group; however, all four strains were assigned to a single species genotypically. DNA from the strains isolated from mussels showed 40-45% genetic relatedness with the DNA of Alteromonas atlantica, 8-36% with DNA of Pseudoalteromonas haloplanktis subsp. haloplanktis, Pseudoalteromonas haloplanktis subsp. tetraodonis, Pseudoalteromonas undina, Pseudoalteromonas nigrifaciens and Pseudoalteromonasas carrageenovora, 53% with Pseudoalteromonas elyakovii, 32-48% with marine P. nigrifaciens from mussels and 14-16% with Alteromonas macleodii. The DNA-DNA hybridization data revealed that the levels of relatedness between the strains isolated and the type strains of Pseudoalteromonas citrea and Pseudoalteromonas fuliginea described recently were significant (95-85%). These results were confirmed by serological data employing polyclonal antibodies to cell surface antigens. The strains isolated from mussels were identified as P. citrea. The hybridization data showed that the name P. fuliginea Romanenko et al. 1994 should be recognized as a junior subjective synonym of P. citrea Gauthier 1977. A notable phenotypic diversity of P. citrea which might be a reflection of their ecological habitats is discussed.

Cellular fatty acids of Alteromonas species

Summary The fatty acid (FA) compositions of 7 type strains and 9 strains isolated from the marine environment, defined by general microbiological methods as members of the genus Alteromonas , were characterized by capillary gas-liquid chromatography (GLC) on polar and non-polar columns. Thirty fatty acids with concentrations exceeding 0.1% were identified, with 16:1(n-7), 16:0, 17:1, 15:0, 18:1(n-7) and 17:0 acids as main components. Principal coordinate analysis of fatty acid data have shown that the majority of the type strains and marine species, identified as Alteromonas sp., formed one group, without species separation. These findings, as well as low amounts of branched chain and hydroxy fatty acids, and an absence of cyclopropane fatty acids in Alteromonas , provides characteristic features for conveniently distinguishing members of this genus from Pseudomonas and other morphologically similar species.

Arenibacter gen. nov., new genus of the family Flavobacteriaceae and description of a new species, Arenibacter latericius sp. nov

Five dark-orange-pigmented, Gram-negative, rod-shaped, non-motile, aerobic bacterial strains were isolated from sandy sediment samples collected in the South China Sea in the Indian Ocean, from a holothurian, Apostichopus japonicus, in the Sea of Japan and from a brown alga, Chorda filum, from the Sea of Okhotsk in the Pacific Ocean. Phenotypic data were collected, demonstrating that the bacteria are chemo-organotrophic and require seawater-based media for growth. Polar lipids were analysed and 27% of the total extract comprised phosphatidylethanolamine as the major component. The predominant cellular fatty acids were branched-chain saturated and unsaturated [i-C15:0, i-C15:1, a-C15:0, C15:0, C16:1(n-7)]. The DNA base composition was 37.5-38.2 mol % G+C. The level of DNA homology of the five isolates was 83-94%, indicating that these isolates belong to the same species. A 16S rDNA sequence of the type strain KMM 426T was determined and phylogenetic analysis, based on neighbour-joining and Fitch-Margoliash methods, revealed that the type strain formed a distinct phyletic line in a clade corresponding to the family Flavobacteriaceae and represented a new genus. From the results of this polyphasic taxonomic analysis, it is proposed that the bacterial strains be classified in a new genus, Arenibacter gen. nov., and species, Arenibacter latericius sp. nov. The type strain is KMM 426T (VKM B 2137DT = LMG 19694T = CIP 106861T).

Identification, isolation and characterization of tetracosapolyenoic acids in lipids of marine coelenterates

Several tetracosapolyenoic acids (TPA) were detected in lipids of different marine coelenterates. Two of these acids were isolated and their structures were confirmed by chemical and spectral methods as all-cis-6,9,12,15,18-tetracosapentaenoic and all-cis-6,9,12,15,18,21-tetracosahexaenoic acid. Their distribution among lipids of a number of species of different classes of coelenterates from the northern and tropical seas, among neutral and polar lipids of these organisms was investigated. Significant quantities of TPA were found in all of the Octacorallia species studied. In some cases the sum of TPA reaches the level of 20% of total lipid fatty acids. The fatty acid composition of different coelenterates is also discussed.

Fatty acids of Heliopora coerulea and chemotaxonomic significance of tetracosapolyenoic acids in coelenterates

Abstract GLC investigation of FA composition of solar coral Heliopora coerulea (Helioporidae, Octacorallia) has revealed the presence of tetracosahexaenoic acid 24:6( n -3) in amounts about 2% of total fatty acids. Earlier, tetracosapolyenoic acids were detected in representatives of all other orders of the subclass Octacorallia: in Alcyonaria, Gorgonaria, and Pennatularia. Therefore, tetracosapolyenoic acids are characteristic for species relating to subclass Octacorallia. The other main fatty acids (over 1% of total fatty acid sum) of H. coerulea were, in descending order, 16:0, 18:3( n -6), 18:0, 20:5( n -3), 14:0, 22:6( n -3), 18:4( n -3), 16:1( n -7), 18:1 ( n -9), 18:2( n -6), and phytanic.

Retrieval of the species Alteromonas tetraodonis Simidu et al. 1990 as Pseudoalteromonas tetraodonis comb. nov. and emendation of description.

A polyphasic taxonomy study was undertaken of three strains of Pseudoalteromonas haloplanktis subsp. tetraodonis (Simidu et al. 1990) Gauthier et al. 1995. DNA was prepared from each of the strains and genomic relatedness was measured by DNA-DNA hybridization. Strains KMM 458T and IAM 14160T shared 99% genetic relatedness, but were only 48-49% related to the type strain of Pseudoalteromonas haloplanktis subsp. haloplanktis, IAM 12915T. The third strain, P. haloplanktis subsp. tetraodonis A-M, showed 83% genetic similarity with P. haloplanktis subsp. haloplanktis IAM 12915T and 32% with KMM 458T. From these results, it is concluded that strains KMM 458T and IAM 14160T comprise a separate species, originally described as Alteromonas tetraodonis, whereas strain A-M belongs to the species Pseudoalteromonas haloplanktis. Based on phenotypic and chemotaxonomic data, genomic fingerprint patterns, DNA-DNA hybridization data and phylogenetic analysis of 16S rRNA, it is proposed that the species Alteromonas tetraodonis be retrieved and recognized as Pseudoalteromonas tetraodonis comb. nov. (type strain IAM 14160T = KMM 458T).

Trans-olefinic very-long-chain patty acid (26:3Δ5c,9c,19t) in lipids of fresh-water sponges of lake baikal

Abstract A novel trans-olefinic very -long-chain fatty acid was found in the lipids of the Lake Baikal sponges. It has a structure of 26:3 5c,9c,19t, as shown by chemical and instrumental methods.

New polar steroids from the sponges Trachyopsis halichondroides and Cymbastela coralliophila

Fractions of trisulfated trihydroxysteroids from the sponges Trachyopsis halichondroides (two different collections) and Cymbastela coralliophila have been isolated and investigated. Ten triacetates were obtained from these fractions by desulfatation/acetylation followed by chromatographic separation, and their structures have been established. Four of these derivatives--namely, triacetates of 5 alpha-pregnane-2 beta,3 alpha,6 alpha-triol (3c), 23,24-dinor-5 alpha-cholane-2 beta,3 alpha,6 alpha-triol (4c), 5 alpha-cholest-22-ene-2 beta,3 alpha,6 alpha-triol (7c), and 24-isopropyl-5 alpha-cholestane-2 beta,3 alpha,6 alpha-triol (11c)-- are described as new derivatives of natural steroids.