Nataliya I. Kalinovskaya

Low-molecular-weight, biologically active compounds from marine Pseudoalteromonas species

We have examined the ability of marine Proteobacteria from the Pseudoalteromonas genus and Alteromonas macleodii to produce low-molecular-weight, biologically active compounds with antimicrobial and surface-active properties. A new marine bacterium, Pseudoalteromonas issachenkonii, exhibited a high level of biological activity and produced antifungal and hemolytic compounds. A detailed spectroscopic investigation based on UV, IR, high-resolution mass spectrometry, and 2D 1H and 13C nuclear magnetic resonance revealed that the former was indole-2,3-dione (isatin). The chemical structure of red-brown pigment (C9H7N3OS3) responsible for hemolytic activity remained unclear. Four of the 15 strains studied (P. luteoviolacea, P. rubra, P. undina, and P. issachenkonii) produced cell-bound, two (P. elaykovii and P. carrageenovora) produced extracellular, and one strain (P. citrea) produced cell-bound and extracellular fatty acids and phospholipids with surface activity. Neither peptides nor glycolipids with surface activity were detected.

Polaribacter butkevichii sp. nov., a Novel Marine Mesophilic Bacterium of the Family Flavobacteriaceae

A novel heterotrophic, yellow pigmented, aerobic, Gram-negative, nonmotile, oxidase- and catalase-positive bacterium KMM 3938T was isolated from sea water collected in the Sea of Japan, Russia. The strain grew at mesophilic temperature range, and required the presence of NaCl for growth. 16S rRNA gene sequence analysis revealed that strain KMM 3938T is a member of the family Flavobacteriaceae. The predominant fatty acids were C13:0 iso, C14:0 iso, C15:0 iso, C15:0, C15:1Δ6, 3OH-C15:0:3 iso, and 3OH-C15:0. The G + C content of the DNA of KMM 3938T was 32.4 mol%. On the basis of phenotypic, chemotaxonomic, genotypic, and phylogenetic characteristics, the novel bacterium was assigned to the genus Polaribacter as Polaribacter butkevichii sp. nov. The type strain is KMM 3938T (= KCTC 12100T = CCUG 48005T).

Surfactin-like structures of five cyclic depsipeptides from the marine isolate ofBacillus pumilus

Five cyclic depsipeptides with molecular masses of 1007, 1021, 1021, 1035, and 1035 were obtained fromBacillus pumilus KMM 150 associated with Australian marine spongeIrcinia sp. Their structures were assigned by mass spectrometric techniques (high-resolution fast atom bombardment and electron impact mass spectrometry), chemical modification, and extensive spectroscopic analysis, including several types of two-dimensional NMR.

Pseudomonas extremorientalis sp. nov., isolated from a drinking water reservoir.

On the basis of phenotypic and genotypic characteristics and 16S rDNA sequence analysis, a novel species belonging to the genus Pseudomonas sensu stricto was identified. The saprophytic, fluorescent bacterium, designated KMM 3447(T), was isolated from a drinking water reservoir near Vladivostok City, Russia. The novel organism was a Gram-negative, aerobic, rod-shaped bacterium that produced a cyclic depsipeptide with surface-active properties. It degraded casein, but did not degrade gelatin, starch, agar or Tween 80. The bacterium was also haemolytic. Growth of the novel bacterium occurred between 4 and 35 degrees C. The predominant cellular fatty acids of the novel pseudomonad were C16:0, C16:1(n-7), C18:1(n-7) and C17.0 cyclo; branched fatty acids were only found in trace amounts. The G+C content of the novel bacterium was 61.0 mol%. 16S rDNA sequence analysis indicated that the novel bacterium had a clear affiliation with Pseudomonas fluorescens and species closely related to this recognized pseudomonad. DNA-DNA hybridization experiments showed that the novel bacterium bound at low levels (27-53%) with the DNA of the type strains of its nearest phylogenetic relatives, namely Pseudomonas tolaasii, Pseudomonas veronii, Pseudomonas orientalis and Pseudomonas rhodesiae, indicating that the novel bacterium represented a novel species within the genus Pseudomonas, for which the name Pseudomonas extremorientalis is proposed; the type strain is KMM 3447(T) (= LMG 19695(T)).

Granulosicoccus coccoides sp. nov., isolated from leaves of seagrass (Zostera marina)

A non-pigmented, motile, Gram-negative bacterium, strain Z 271(T), was isolated from the surface of leaves of the seagrass Zostera marina which was collected in Troitza Bay (Sea of Japan, Pacific Ocean). The new isolate grew between 5 degrees C and 28 degrees C and was slightly halophilic, tolerating environments containing up to 5 % (w/v) NaCl. Strain Z 271(T) was able to degrade Tweens 20, 40 and 80 and partially degrade gelatin, but was unable to degrade casein. Phosphatidylethanolamine (36.9 %) and phosphatidylglycerol (63.1 %) were the predominant phospholipids. The major fatty acids included C(18 : 1)omega7c (43.7 %), C(16 : 1)omega7c (31.1 %) and C(16 : 0) (16.8 %). The main respiratory quinone was Q-8. The DNA-DNA relatedness value of strain Z 271(T) with Granulosicoccus antarcticus IMCC3135(T) was 35 %. The G+C content of the DNA of strain Z 271(T) was 60.2 mol%. On the basis of phenotypic and genotypic characteristics and 16S rRNA gene sequence analysis, strain Z 271(T) represents a novel species of the genus Granulosicoccus for which the name Granulosicoccus coccoides sp. nov. is proposed. The type strain is Z 271(T) (=KMM 6014(T)=CIP 109923(T)).

Celeribacter neptunius gen. nov., sp. nov., a new member of the class Alphaproteobacteria

A whitish Gram-negative, motile, aerobic bacterium, designated strain H 14(T), was isolated from seawater collected at St Kilda beach in Port Phillip Bay, Melbourne, Australia. Analysis of 16S rRNA gene sequences revealed that the organism belonged to the Roseobacter lineage of the class Alphaproteobacteria, forming a distinct evolutionary lineage at the genus level. Strain H 14(T) was distantly related to the genera Nautella, Ruegeria and Pseudoruegeria (family Rhodobacteraceae). Strain H 14(T) was unable to degrade gelatin, casein, chitin, agar and starch, did not produce any carotenoids, did not possess bacteriochlorophyll a and had a limited ability to utilize carbon sources. Strain H 14(T) grew with concentrations of 1-8 % (w/v) NaCl and over a temperature range of 5-35 degrees C. Phosphatidylglycerol was the major phospholipid (90 %); phosphatidylcholine (7.9 %) and phosphatidylethanolamine (2.0 %) were present in minor quantities. The predominant fatty acids were C(18 : 1)omega7c (82.4 %), C(18 : 1)omega9c (5.1 %) and C(18 : 0) (3.8 %). The DNA G+C composition for strain H 14(T) was 59.1 mol%. Based on the results of physiological, biochemical, chemotaxonomic and phylogenetic investigations, a new genus, Celeribacter gen. nov., with the type species Celeribacter neptunius sp. nov. is proposed. The type strain of the type species is H 14(T) (=KMM 6012(T)=CIP 109922(T)).

Marine isolate Citricoccus sp. KMM 3890 as a source of a cyclic siderophore nocardamine with antitumor activity.

A novel actinobacterium, designated KMM 3890 was isolated from a bottom sediment sample collected from the Sakhalin shallow environment. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated strain KMM 3890 affiliation to the genus Citricoccus. In addition to its hemolytic activity, this strain exhibited inhibitory activity against Gram-positive bacteria. It was found that the marine isolate Citricoccus sp. KMM 3890 produced and excreted into the culture medium a large amount of the compound, which was isolated and structurally characterized as known cyclic siderophore nocardamine on the basis of combined spectral analyses. Nocardamine showed inhibitory effects to colony formation of T-47D, SK-Mel-5, SK-Mel-28 and PRMI-7951 tumor cell lines and a weak antimicrobial against Gram-positive bacteria and no revealed cytotoxic activity. This study can be considered as the first report on marine isolate of the genus Citricoccus producing nocardamine with antitumor activity.

Pacificibacter maritimus gen. nov., sp. nov., isolated from shallow marine sediment

An aerobic, Gram-stain-negative, non-pigmented, non-motile bacterium, strain KMM 9031(T), was isolated from a sandy sediment sample collected from the shore of the Sea of Japan and subjected to phenotypic and phylogenetic analysis. Based on comparative 16S rRNA gene sequence analysis, strain KMM 9031(T) constituted a separate phylogenetic line within the Roseobacter clade of the class Alphaproteobacteria, sharing highest sequence similarities with members of the genera Roseovarius (92.7-95.3 %), Pseudoruegeria (94.5 %), Sulfitobacter (92.7-94.4 %) and Thalassobacter (94.2-94.3 %). The predominant fatty acid of strain KMM 9031(T) was C(18 : 1)ω7c, with C(16 : 0), C(10 : 0) 3-OH and C(12 : 1) 3-OH present in lesser amounts. The DNA G+C content of the isolate was 52.6 mol%. The major isoprenoid quinone was Q-10 and polar lipids comprised phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol and two unknown lipids. On the basis of phylogenetic analysis and physiological and biochemical characterization, strain KMM 9031(T) represents a novel species in a new genus, for which the name Pacificibacter maritimus gen. nov., sp. nov. is proposed; the type strain is KMM 9031(T) ( = NRIC 0785(T)  = JCM 17096(T)).

Taxonomic Composition and Biological Activity of Microorganisms Associated with a Marine Ascidian Halocynthia aurantium

The taxonomy and biological activity of 176 heterotrophic microorganisms associated with the ascidian Halocynthia aurantiumfrom the coastal waters of Peter the Great Bay (Sea of Japan) were studied. In the microbial community, bacteria of the genera Pseudoalteromonas(38% of all strains studied) and Bacillus(25%) prevailed and showed high biological activity. Bacteria of Pseudoalteromonaswere capable of extracellular hydrolases production and exhibited high antibiotic and antimicrobial properties. Five Pseudoalteromonasstrains were capable of restriction enzyme production. A significant proportion of the pseudoalteromonads inhibited growth ofProteus vulgarisand Candida albicans(81 and 84%, respectively). Spore-forming bacteria of Bacilluswere capable of chitin hydrolysis and extracellular inducible RNAses production (23%). They were active against Staphylococcus aureusand Bacillus subtilis(39 and 23%, respectively). Bacillus pumilusstrain KMM 1364 showed hemolytic activity and antagonistic properties against S. aureusand was found to produce surface active glycolipids and surfactinlike cyclic depsipeptides.

Reclassification of Roseivirga seohaensis (Yoon et al. 2005) Lau et al. 2006 as a later synonym of Roseivirga ehrenbergii Nedashkovskaya et al. 2005 and emendation of the species description.

The precise taxonomic position of Roseivirga seohaensis strain SW-152T, formerly [Marinicola] seohaensis, was established. On the basis of data from DNA-DNA reassociation experiments and phenotypic analysis, it is proposed that this strain should be considered as a later heterotypic synonym of Roseivirga ehrenbergii KMM 6017T Nedashkovskaya et al. 2005. Emended descriptions for Roseivirga ehrenbergii and for the genus Roseivirga are also given.