Yulia V. Alexeeva

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Two whitish yellow, Gram-positive, non-motile, aerobic bacteria were isolated from enrichment culture during degradation of the thallus of the brown alga Fucus evanescens. The bacteria studied were chemo-organotrophic, mesophilic and grew well on nutrient media containing up to 15 % (w/v) NaCl. The DNA G+C content was 61 mol%. The two isolates exhibited a(More)
A survey of the extracellular ATP levels of 86 heterotrophic bacteria showed that gram-negative bacteria of the genera Sulfitobacter, Staleya, and Marinobacter secreted elevated amounts of extracellular ATP, ranging from 6.0 to 9.8 pM ATP/colony forming unit (cfu), and that gram-positive bacteria of the genera Kocuria and Planococcus secreted up to 4.1 pM(More)
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(More)
Four light-yellow-pigmented, Gram-negative, short-rod-shaped, non-motile isolates were obtained from enrichment culture during degradation of the thallus of the brown alga Fucus evanescens. The isolates studied were chemo-organotrophic, alkalitolerant and mesophilic. Polar lipids were analysed and phosphatidylethanolamine was the only phospholipid(More)
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(More)
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(More)
AIMS The present work aimed to study the effects of cultivation conditions on the haemolytic activities of Pseudoalteromonas issachenkonii. METHODS AND RESULTS The kinetics of growth and haemolytic activities was investigated on sea-salts and NaCl-based nutrient media supplemented with either starch, or KBr over a period of 140 h. The first haemolytic(More)
AIMS The present work aimed to design an optimized medium to yield a higher production of glycosides by Pseudoalteromonas issachenkonii KMM 3549(T). METHODS AND RESULTS Higher levels of fucoidan hydrolase, alginase, laminaranase and b-N-acetylglucosaminidase production were obtained with peptone concentrations ranging from 2.5 g l(-1) to 10 g l(-1), while(More)
The marine bacterium “Pseudoalteromonas januaria” SUT 11 isolated from a seawater sample produced the rare cell-bound cyclic lipodepsipeptides A/A′, B/B′, and C/C′. The matrix-assisted laser desorption/ionization mass spectra indicated that one bromine atom presented in the peptides B/B′ and C/C′, whereas the component A/A′ contained no bromine atom. The(More)
Two orange-pigmented Gram-positive, aerobic bacteria were isolated from enrichment culture during degradation of brown alga Fucus evanescens thalluses. In this work, atomic force microscopy (AFM) has been used to study the cell morphology. The non-contact mode imaging revealed unusual irregular coccoid shape of cells, possessing a single flagellum. Bacteria(More)