Vassilii I. Svetashev

Evaluation of Phospholipid and Fatty Acid Compositions as Chemotaxonomic Markers of Alteromonas-Like Proteobacteria

The cellular phospholipids (PLs) and fatty acids (FAs) were investigated in type and environmental strains of Pseudoalteromonas, Alteromonas macleodii, A. infernus, and in three type strains of Marinomonas, M. communis, M. vaga, M. mediterranea. A total of 40 strains (19 strains in this study and 21 reported in previous papers), including Idiomarina abyssalis, I. zobellii, and Glaciecola punicea, G. pallidula, aerobic Alteromonas-like proteobacteria showed genus-characteristic patterns of phospholipids and fatty acids useful for genera discrimination. The PL patterns of surface cultures of alteromonads, pseudoalteromonads, and marinomonads consisted almost entirely of phosphatidyl ethanolamine and phosphatidyl glycerol presented in different proportions. Neither diphosphatidyl glycerol nor glycophospholipids were found in bacteria studied. In addition, the minor amount of a glycolipid was found in all strains studied. Bacteria of the genera Marinomonas, Idiomarina, and Glaciecola were clearly distinguished by presence of one of the major FAs: 18:1 (n-7), i15:0, and 16:1 (n-7), respectively. The amounts of these FAs reached up to 40–60% of total FAs. Members of Alteromonas and Pseudoalteromonas were characterized by different ratio of the following major FAs:16:1(n-7), 16:0, 17:1 (n-8), and 18:1 (n-7).

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.

Pseudoalteromonas ruthenica sp. nov., isolated from marine invertebrates

On the basis of phenotypic and genotypic characteristics and analysis of 165 rRNA sequences, a novel species belonging to the genus Pseudoalteromonas is described. Two pale-orange-pigmented strains, KMM 300T and KMM 290, isolated respectively from a mussel, Crenomytilus grayanus, and a scallop, Patinopecten yessoensis, are marine, gram-negative, aerobic, rod-shaped bacteria that produce a number of antimicrobial compounds. The strains are able to degrade gelatin, elastin, starch, DNA and Tween 80. Chitin and agar are not degraded. The isolates from marine invertebrates grew at NaCl concentrations of 1-9% and a temperature range of 10-35 degrees C and did not utilize most of the wide range of carbohydrates tested, with the exception of D-glucose, cellobiose and sucrose. The DNA G+C content was 48.4-48.9 mol%. The level of DNA homology of the two strains was 98%. DNA from the strains isolated from marine invertebrates showed 5-15% genetic relatedness to the DNA of other type strains of the genus Pseudoalteromonas. 16S rRNA analysis indicated a clear affiliation of the novel bacteria to other species of the genus. The strains are assigned to a novel species, Pseudomonas ruthenica sp. nov., with the type strain KMM 300T (= LMG 19699T = CIP 106857T).

Luteimonas vadosa sp. nov., isolated from seashore sediment.

An aerobic, Gram-stain-negative, yellow-pigmented, non-motile, rod-shaped bacterium designated strain KMM 9005(T) was isolated from a sediment sample collected from the Sea of Japan seashore. Comparative 16S rRNA gene sequence analysis showed that strain KMM 9005(T) belonged to the genus Luteimonas and was most closely related to Luteimonas cucumeris KCTC 23627(T) (96.5 % sequence similarity) and Luteimonas aquatica LMG 24212(T) (96.1 % sequence similarity). Strain KMM 9005(T) was characterized by the presence of thin fimbriae, the major ubiquinone Q-8, by the predominance of iso-C17 : 1 followed by iso-C16 : 0, iso-C15 : 0 and iso-C17 : 0 in its fatty acid profile, weak hydrolytic capacity and the inability to assimilate most organic substrates. Based on these distinctive phenotypic characteristics and phylogenetic analysis, strain KMM 9005(T) represents a novel species of the genus Luteimonas, for which the name Luteimonas vadosa sp. nov. is proposed. The type strain is KMM 9005(T) ( = NRIC 0881(T) = JCM 18392(T)).

A New Cytotoxic Fatty Acid (5Z,9Z)-22-Methyl-5,9- tetracosadienoic Acid and the Sterols from the Far Eastern Sponge Geodinella robusta

A new fatty acid, (5Z,9Z)-22-methyl-5,9-tetracosadienoic acid (1a), and a rare fatty acid, (5Z,9Z)-23-methyl-5,9-tetracosadienoic acid (2a), the predominant constituents of the free fatty acid fraction from the lipids of the sponge Geodinella robusta, were isolated and partly separated by reversed phase high-performance liquid chromatography, followed by multifold crystallization from MeOH to give 1a and 2a in 70% and 60% purity, respectively. These fatty acids were identified as (5Z,9Z)-22-and (5Z,9Z)-23-methyl-5,9-tetracosadienoic acids by nuclear magnetic resonance techniques, including distortionless enhancement by polarization transfer, heteronuclear multiple quantum connectivity, and correlation spectroscopy experiments, as well as from mass-spectrometric data for their methyl esters, the methyl esters of their perhydro derivatives, and their pyrrolidides. Mixtures of 1a and 2a showed cytotoxic activity against mouse Ehrlich carcinoma cells and a hemolytic effect on mouse erythrocytes. The sterol fraction from the same sponge was analyzed by gas liquid chromatography mass spectrometry, and 24-methylenecholesterol was identified as a main constituent of this fraction. The implications of the co-occurrence of membranolytic long-chain fatty acids and 24-methylenecholesterol as a main membrane sterol are discussed in terms of the phenomenon of biochemical coordination.

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.

Description of Cobetia amphilecti sp. nov., Cobetia litoralis sp. nov. and Cobetia pacifica sp. nov., classification of Halomonas halodurans as a later heterotypic synonym of Cobetia marina and emended descriptions of the genus Cobetia and Cobetia marina

A group of five Gram-negative, aerobic, halotolerant, non-pigmented bacteria isolated from shallow sediment samples and invertebrate specimens collected from the Gulf of Alaska and the Sea of Japan was subjected to taxonomic study. On the basis of 16S rRNA gene sequence analysis, the novel isolates were affiliated to the genus Cobetia, sharing the highest sequence similarity of 99.3-99.9 % with Cobetia marina DSM 4741(T). DNA-DNA hybridization experiments between and among the novel strains and C. marina DSM 4741(T) and Cobetia crustatorum JCM 15644(T) revealed that the five strains represent three separate genospecies, which could be differentiated in their morphological, physiological and biochemical characteristics. Halomonas halodurans NBRC 15607(T) was included in this study as it has recently been reported to exhibit high 16S rRNA gene sequence similarity to C. marina DSM 4741(T), and it showed a high DNA relatedness value of 96 % with C. marina DSM 4741(T), indicating that they belong to the same species. On the basis of phylogenetic analysis, DNA-DNA hybridization and phenotypic characterization, three novel species are proposed, named Cobetia amphilecti sp. nov. (type strain KMM 1561(T) = NRIC 0815(T) = CCUG 49560(T)), Cobetia litoralis sp. nov. (type strain KMM 3880(T) =NRIC 0814(T) =CCUG 49563(T)) and Cobetia pacifica sp. nov. (type strain KMM 3879(T) = NRIC 0813(T) = CCUG 49562(T)). It is also proposed that Halomonas halodurans is a later heterotypic synonym of Cobetia marina, and emended descriptions of the genus Cobetia and the species Cobetia marina are provided.

Litoreibacter albidus gen. nov., sp. nov. and Litoreibacter janthinus sp. nov., members of the class Alphaproteobacteria isolated from the seashore

Two Gram-negative, strictly aerobic, non-motile bacteria designated strains KMM 3851(T) and KMM 3842(T) were respectively isolated from a marine snail specimen (Umbonium costatum) and from surrounding sediments collected simultaneously from the shore of the Sea of Japan. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains KMM 3851(T) and KMM 3842(T) were affiliated with the Roseobacter lineage of the class Alphaproteobacteria as a separate phylogenetic line adjacent to the members of the genus Thalassobacter. These novel isolates shared 98.5 % 16S rRNA gene sequence similarity and 15 % DNA-DNA relatedness. The major isoprenoid quinone of both strains was Q-10 and polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and aminophospholipids. In addition, strain KMM 3851(T) contained two unknown lipids, whereas strain KMM 3842(T) contained diphosphatidylglycerol. Fatty acid analysis revealed C(18 : 1)ω7c and C(16 : 0) as major components and small amounts of C(18 : 2). The DNA G+C contents were 60.4 mol% (KMM 3851(T)) and 58.5 mol% (KMM 3842(T)). Based on distinctive phenotypic characteristics, DNA-DNA hybridization data and phylogenetic distance, strains KMM 3851(T) and KMM 3842(T) should be classified as representatives of two novel species in a new genus, Litoreibacter gen. nov., with the type species Litoreibacter albidus sp. nov. (type strain KMM 3851(T) =NRIC 0773(T) =JCM 16493(T)) and a second species Litoreibacter janthinus sp. nov. (type strain KMM 3842(T) =NRIC 0772(T) =JCM 16492(T)).