• Title, Summary, Keyword: marine bacterium

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Isolation and Characterization of Novel Alginate-Degrading Pseudoalteromonas sp. Y-4

  • Cho, Hyeon-Ah;Kim, Hyun-Woo;Kim, Young-Mog
    • Fisheries and aquatic sciences
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    • v.15 no.3
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    • pp.259-263
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    • 2012
  • To isolate an alginate-degrading bacterium, we conducted a single colony isolation using a solid medium containing alginate as the sole carbon source. A marine bacterium Y-4 capable of degrading alginate was isolated from seawater. The strain was identified to be Pseudoalteromonas sp., based on morphological, biochemical, 16S rDNA homology, and phylogenetic analyses. Moreover, Pseudoalteromonas sp. Y-4 exhibited alginate lyase activity in the presence of 4% alginate even though many known alginate-degrading bacteria degrade in the range of 0.5-1% alginate. The optimum culture conditions for the Y-4 strain were 2% alginate, pH 8.0, and 3% NaCl at $30^{\circ}C$. The highest alginate lyase activity was also observed under the same conditions. To our knowledge, this is the first reported isolation of a marine bacterium degrading high concentrations of alginate.

Properties of an Extracellular Amylase Produced by the Marine Halophilic Bacterium Vibrio alginolyticus (해양 호염성 세균 Vibrio alginolyticus가 생산하는 Extracellular Amylase의 특성)

  • 김영재
    • Microbiology and Biotechnology Letters
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    • v.27 no.3
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    • pp.203-207
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    • 1999
  • V. alginolyticus 138-2, a marine halophilic bacterium, produced an extracellular amylase with a molecular weight of ca. 56,000. The analysis of the digestion products of soluble starch by thin layer chromatography(TLC) revealed that the extracellular amylase of V. alginolyticus 138-2 is a saccharifying-type alpha-amylase. The alpha-amylase activity of the culture supernatant of soluble starch was optimal at pH 6.0 and 45$^{\circ}C$. Ca2+ slightly increased the alpha-amylase activity, whereas Hg2+, An2+, Cu2+, Ni2+, Fe2+, and Mn2+inhibited the enzymatic activity. Alkylating thiol group agent, iodoacetic acid did not affect the alpha-amylase activity, but reduced thiol reagents such as dithiothreitol, cysteine, and beta-mercaptoethanol stimulated theenzymatic activity. On the other hand, even if V. alginolyticus 138-2 is a marine halophilic bacterium, its alpha-amylase activity was significantly inhibited by NaCl.

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Four Butenolides are Novel Cytotoxic Compounds Isolated from the Marine-Derived Bacterium, Streptoverticillium luteoverticillatum 11014

  • Li, De-Hai;Zhu, Tian-Jiao;Liu, Hong-Bing;Fang, Yu-Chun;Gu, Qian-Qun;Zhu, Wei-Ming
    • Archives of Pharmacal Research
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    • v.29 no.8
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    • pp.624-626
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    • 2006
  • Four known butenolides were isolated from the ethyl acetate extracts of the culture broth of the marine-derived bacterium, Streptoverticillium luteoverticillatum, by bioassay-guided fractionation. The structures were identified on the basis of spectral data. The absolute configuration of compound (1) was determined by CD spectrum for the first time. Compounds 1-4 showed in vitro cytotoxicity against the murine lymphoma P388 and human leukemia K562 cell lines. This is the first report on the isolation of butenolides from the marine bacterium, Streptoverticillium luteoverticillatum, and their cytotoxic activities.

Antifouling Activity towards Mussel by Small-Molecule Compounds from a Strain of Vibrio alginolyticus Bacterium Associated with Sea Anemone Haliplanella sp.

  • Wang, Xiang;Huang, Yanqiu;Sheng, Yanqing;Su, Pei;Qiu, Yan;Ke, Caihuan;Feng, Danqing
    • Journal of Microbiology and Biotechnology
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    • v.27 no.3
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    • pp.460-470
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    • 2017
  • Mussels are major fouling organisms causing serious technical and economic problems. In this study, antifouling activity towards mussel was found in three compounds isolated from a marine bacterium associated with the sea anemone Haliplanella sp. This bacterial strain, called PE2, was identified as Vibrio alginolyticus using morphology, biochemical tests, and phylogenetic analysis based on sequences of 16S rRNA and four housekeeping genes (rpoD, gyrB, rctB, and toxR). Three small-molecule compounds (indole, 3-formylindole, and cyclo (Pro-Leu)) were purified from the ethyl acetate extract of V. alginolyticus PE2 using column chromatography techniques. They all significantly inhibited byssal thread production of the green mussel Perna viridis, with $EC_{50}$ values of $24.45{\mu}g/ml$ for indole, $50.07{\mu}g/ml$ for 3-formylindole, and $49.24{\mu}g/ml$ for cyclo (Pro-Leu). Previous research on the antifouling activity of metabolites from marine bacteria towards mussels is scarce. Indole, 3-formylindole and cyclo (Pro-Leu) also exhibited antifouling activity against settlement of the barnacle Balanus albicostatus ($EC_{50}$ values of 8.84, 0.43, and $11.35{\mu}g/ml$, respectively) and the marine bacterium Pseudomonas sp. ($EC_{50}$ values of 42.68, 69.68, and $39.05{\mu}g/ml$, respectively). These results suggested that the three compounds are potentially useful for environmentally friendly mussel control and/or the development of new antifouling additives that are effective against several biofoulers.

Isolation and Identification of a Photosynthetic Bacterium Containing $Q_{10}$ ($Q_{10}$ 함유 광합성세균의 분리 및 동정)

  • Jeong, Soo Kyoung;Kim, Joong Kyun
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.2
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    • pp.120-122
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    • 2007
  • A $Q_{10}$-producing photosynthetic bacterium was isolated from the silt at Nakdong river. The isolate had 1.55 mg of $Q_{10}$ per gram of dry cell. By the 16s-rDNA sequence analysis, the isolate was found to be Rhodobacter sphaeroids with 100% similarity (Genbank Accession No.=AM696701).

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Production of Bioemulsifier from a Marine Bacterium Achromobacter sp. M-1220 (해양세균 Achromobacter sp. M-1220 균주를 이용한 생물유화제 물질의 생산)

  • 박중연;홍용기
    • Microbiology and Biotechnology Letters
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    • v.17 no.3
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    • pp.252-256
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    • 1989
  • A marine bacterium which was isolated from the enrichment culture for the emulsification of Bunker-C oil produced a bioemulsifier potently. The strain identified as an Achromobacter sp. M-1220. The bioemulsifier was produced during mid-logarithmic phase in hexadecane oil medium at 18$^{\circ}C$. It appeared to be a cationic peptidolipid substance and showed an active stabilizing effect on the emulsion of crude oils and a few vegetable oils.

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Effects of Aeration Rates on Production on Extracellular Polysaccharide, EPS-R, by Marine Bacterium Hahella chejuensis

  • Lee, Hyung-Sang;Park, Shin-Hye;Lee, Jong-Ho;Lee, Hong-Kum
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.6 no.5
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    • pp.359-362
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    • 2001
  • The production of an extracellular polysaccharide, EPS-R, from the marine bacterium Hahella chejuensis was investigated at various aeration rates in a batch culture. Higher aeration rate resulted in enhanced EPS production and increased the viscosity of the culture broth. At an aeration rate of 1.5 vvm, EPS-R (12.2 g/L) was obtained with a yield (Y$\_$p/s) of 0.6 from the STN medium after 72 h of cultivation. The H. chejuensis cells changed rod morphology to a short-rod form in the stationary growth phase.

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Characteristics of Red Pigment from Marine Bacterium Utilizing Colloidal Chitin

  • Ryu, Byeong-Ho;Kim, Min-Jeong
    • 한국생물공학회:학술대회논문집
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    • pp.169-172
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    • 2000
  • Studies on extraction of red pigment was performed to provide the basic information for the utilization of red pigment as s new source of natural food colorant. A bacterium isolated from marine resources were carried out the test for excretion of red pigment. One strain of a marine bacterium, KSR-97 showed a high production of red pigment on the medium of colloidal chitin, peptone-yeast extract with minerals. In physicochemical and sensory properties in aqueous solution of red pigment was investigated at various condition of pH, temperature, concentration of ethanol and stability of storage. Potent antioxidative of red pigment was separated by thin layer chromatograpy, silica gel chromatography and reverse high performance liquid chromatography using ODS hypersil column.

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Analysis of a Prodigiosin Biosynthetic Gene Cluster from the Marine Bacterium Hahella chejuensis KCTC 2396

  • Kim, Doc-Kyu;Park, Yon-Kyoung;Lee, Jong-Suk;F. Kim, Ji-Hyun;Jeong, Hae-Young;Kim, Beom-Seok;Lee, Choong-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.16 no.12
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    • pp.1912-1918
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    • 2006
  • Marine bacterium Hahella chejuensis KCTC 2396 simultaneously produced red antibiotic prodigiosin and undecylprodiginine. A complete set of the prodigiosin biosynthetic gene cluster has been cloned, sequenced, and successfully expressed in a heterologous host. Sequence analysis of the gene cluster revealed 14 ORFs showing high similarity to pig and red genes from Serratia spp. and Streptomyces coelicolor A3(2), respectively, and the gene organization was almost: similar to that of pig genes. These genes were named hap for Hahella prodigiosin, and determined to be transcribed as a single operon, by RT-PCR experiment. Based on the hap gene mutagenesis experiments and comparative analysis with pig and red genes, we propose a prodigiosin-biosynthetic pathway in KCTC 2396.