Elena P. Ivanova

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.

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).

Degradation of fucoidan by the marine proteobacterium Pseudoalteromonas citrea

It was found that Pseudoalteromonas citrea strains KMM 3296 and KMM 3298 isolated from the brown algae Fucus evanescens and Chorda filum, respectively, and strain 3297 isolated from the sea cucumber Apostichopus japonicus are able to degrade fucoidans. The fucoidanases of these strains efficiently degraded the fucoidan of brown algae at pH 6.5–7.0 and remained active at 40–50°C. The endo-type hydrolysis of fucoidan resulted in the formation of sulfated α-L-fucooligosaccharides. The other nine strains of P. citrea studied (including the type strain of this species), which were isolated from other habitats, were not able to degrade fucoidan.

Two species of culturable bacteria associated with degradation of brown algae Fucus Evanescens

The heterotrophic microbial enrichment community established during degradation of brown algae Fucus evanescens was characterized. A two-species bacterial community of marine culturable gamma-proteobacteria consisted of Pseudoalteromonas and Halomonas. The first member of the community, Pseudoalteromonas sp., was highly metabolically active, had bacteriolytic and hemolytic activities, produced proteinases (gelatinase and caseinase), lipases, DNases, and fucoidanhydrolases, laminaranases, alginases, pustulanases, beta-glucosidases, beta-galactosidases, beta-N-acetylglucosaminidases, and beta-xylosidases. The second member of the community, Halomonas marina, produced only caseinase and DNase, and it did not hydrolyze algal polysaccharides. Both members of the studied bacterial community utilized a range of easily assimilable monosaccharides and other low molecular weight organic substances. The results provide an evidence of the complex metabolic interrelations between two members of this culturable community. One of them Pseudoalteromonas sp., most likely plays the major role in the initial stages of algal degradation; the other one, H. marina, resistant to the bacteriolytic activity of the former, is able to utilize the products of degradation of polysaccharides.

Characterization of Surfactin-like Cyclic Depsipeptides Synthesized by Bacillus pumilus from Ascidian Halocynthia aurantium

Abstract: A marine bacterium (KMM 1364), identified as Bacillus pumilus, was isolated from the surface of ascidian Halocynthia aurantium. Structural analysis revealed that the strain KMM 1364 produced a mixture of lipopeptide surfactin analogs with major components with molecular masses of 1035, 1049, 1063, and 1077. The variation in molecular weight represents changes in the number of methylene groups in the lipid and/or peptide portions of the compounds. Structurally, these lipopeptides differ from surfactin in the substitution of the valine residue in position 4 by leucine, and have been isolated as two carboxy-terminal variants, with valine or isoleucine in position 7. As constituents of the lipophilic part of the peptides, only β-hydroxy-C15-, β-hydroxy-C16-, and a high amount of β-hydroxy-C17 fatty acid were determined.

A Highly Active Alkaline Phosphatase from the Marine Bacterium Cobetia

An alkaline phosphatase with unusually high specific activity has been found to be produced by the marine bacterium Cobetia marina (strain KMM MC-296) isolated from coelomic liquid of the mussel Crenomytilus grayanus. The properties of enzyme, such as a very high specific activity (15000 DE U/1 mg of protein), no activation with divalent cations, resistance to high concentrations of inorganic phosphorus, as well as substrate specificity toward 5′ nucleotides suggest that the enzyme falls in an intermediate position between unspecific alkaline phosphatases (EC 3.1.3.1) and 5′ nucleotidases (EC 3.1.3.5).

Characterization of Aeromonas and Vibrio species isolated from a drinking water reservoir

E.P. IVANOVA, N.V. ZHUKOVA, N.M. GORSHKOVA AND E.L. CHAIKINA. 2001.

Winogradskyella exilis sp. nov., isolated from the starfish Stellaster equestris, and emended description of the genus Winogradskyella

A pale-yellowish-pigmented strain, 022-2-26(T), was isolated from a starfish, Stellaster equestris. Cells of strain 022-2-26(T) were Gram-negative short rods that were chemo-organotrophic, alkalitolerant and mesophilic. The predominant menaquinone was MK-6. The major cellular fatty acids were iso-C(15 : 0), iso-C(15 : 1), C(15 : 0), iso-C(15 : 0) 2-OH and iso-C(17 : 0) 3-OH (together representing 87 % of the total fatty acids). The DNA G+C content was 30.1 mol%. A 16S rRNA gene sequence of the isolate was determined and phylogenetic analyses revealed that strain 022-2-26(T) formed a robust clade (neighbour-joining algorithm with a bootstrap value of 95 % and parsimony and maximum-likelihood algorithms) with type strains of species in the genus Winogradskyella. The closest phylogenetic neighbour of strain 022-2-26(T) was Winogradskyella poriferorum UST030701-295(T) (96 % 16S rRNA gene sequence similarity; 59 differences between sequences). On the basis of the phenotypic and chemotaxonomic characteristics and the phylogenetic evidence, it is proposed that strain 022-2-26(T) represents a novel species, Winogradskyella exilis sp. nov. The type strain is 022-2-26(T) (=KMM 6013(T) =CIP 109976(T)).

Ecophysiological variabilities in Ectohydrolytic enzyme activities of some Pseudoalteromonas species, P. citrea, P. issachenkonii, and P. nigrifaciens

The ecophysiological variabilities in the ectohydrolytic enzyme profiles of the three species of Pseudoalteromonas, P. citrea, P. issachenkonii, and P. nigrifaciens, have been investigated. Forty-one bacteria isolated from several invertebrates, macroalgae, sea grass, and the surrounding water exhibited different patterns of hydrolytic enzyme activities measured as the hydrolysis of either native biopolymers or fluorogenic substrates. The activities of the following enzymes were assayed: proteinase, tyrosinase, lipase, amylase, chitinase, agarase, fucoidan hydrolase, laminaranase, alginase, pustulanase, cellulase, β-glucosidase, α- and β-galactosidases, β-N-acetylglucosaminidase, β-glucosaminidase, β-xylosidase, and α-mannosidase. The occurrence and cell-specific activities of all enzymes varied over a broad range (from 0 to 44 μmol EU per hour) and depended not only on taxonomic affiliation of the strain, but also on the source/place of its isolation. This suggests ‘specialization’ of different species for different types of polymeric substrates as, for example, all strains of P. citrea and P. issachenkonii hydrolyzed alginate and laminaran, while strains of P. nigrifaciens were lacking the ability to hydrolyze most of the algal polysaccharides. The incidence of certain enzymes such as fucoidan hydrolases, alginate lyases, agarases, and α-galactosidases might be strain specific and reflect its particular ecological habitat.

A New Family, Alteromonadaceae fam. nov., Including Marine Proteobacteria of the Genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia

The taxonomic positions of the marine genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia within the gamma subclass of the class Proteobacteria were specified on the basis of their phenotypic, genotypic, and phylogenetic characteristics. Gram-negative aerobic bacteria of the genera Alteromonas, Pseudoalteromonas, and Idiomarina and facultatively anaerobic bacteria of the genus Colwellia were found to form a phylogenetic cluster with a 16S rRNA sequence homology of 90% or higher. The characteristics of these genera presented in this paper allow their reliable taxonomic identification. Based on the analysis of our experimental data and analyses available in the literature, we propose to combine the genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia into a new family, Alteromonadaceae fam. nov., with the type genus Alteromonas.