• Title/Summary/Keyword: hydrophila

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Improvement of bacteria for removing of phosphate by spheroplast fusion (원형질체 융합에 의한 인산염 제거균주의 개량)

  • 윤성녀;조경주;조홍범;최영길
    • Korean Journal of Microbiology
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    • v.29 no.2
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    • pp.117-122
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    • 1991
  • In order to improve the removal ability of phosphate, Spheroplast fusions were performed among auxotrophic mutants of Aeromonas hydrophila isolated from waste water, named A13 and A14, Aci37 auxotrophic mutant of Acinetobactercalcoaceticus, and auxotrophic E. coli HR262/pCE27 carring pit gene. Eight fusants obtained from this experiment showed different biochemical characteristics. When the rate of phosphate uptake among fusants (F1-F8) was investigated in Phosphate Uptake Medium (PUM), F8 strain showed the highest rate for phosphate removal, 7 times as much as control after two hours incubation. The role of cations ($Mg^{++}$ ,$Ca^{++}$ , $K^{+}$ in phosphate uptade by F8 was also investigated in PUM without each salt. $K^{+}$ seemed to be crucial. Being compared with phosphate untake rate in PUM, that in PUM without $K^{+}$ was reduced 1.5 times. Therefore, by applying F8 strain and $K^{+}$ in practical environmental system, the increased efficiency in phosphate removal can be derived.

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Isolation, Identification and Chitinolytic Properties of Aeromonas hydrophila

  • Kim, Kwang-Yup;Lee, Ke-Ho
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.522.3-523
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    • 1986
  • A Screening test was carried out for chitin-decomposing bacteria. In 100 samples from soil, fesh water and sea water, 7 strains of Chitinolytic bacteria were isolated. 5-3K which exhibited the highest chitinase activity was identified as Aeromonas hydrophila and cultural conditions from maximum chitinase production were determined. Optimum Chitinase production was obtained at pH 7, 33eC and with chitin concentration greater tham 0.2% Under optimal conditions, high yields of Chitinase were obtained in 16-30 hours. Chitinase was purified by ammonium sulfate precipitation and sephadex G-100 gel-filtration from the culture filtrgte.

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Antagonistic Effect of Chitinolytic Bacteria on Soilborne Plant Pathogens (토양전염성 식물병원균에 대한 Chitin 분해세균들의 길항효과)

  • 박서기;이효연;김기청
    • Korean Journal Plant Pathology
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    • v.11 no.1
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    • pp.47-52
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    • 1995
  • One hundred and thirty bacterial isolates with high chitinolytic activity on chitin agar media were isolated and identified. Most of the isolates were Aeromonas hydrophila (110 isolates), and the others were Serratia marcescens (11 isolates), Aeromonas caviae (3 isolates), Chromobacterium violaceum strain C-61 (2 isolates), Chromobacterium violaceum strain C-72 (1 isolate) and unknown species (3 isolates). Among them, C. violaceum strain C-61 had highest chitinolytic activity and fungal growth inhibition on PDA. This bacterium also inhibited the growth of Rhizoctonia solani, Sclerotinia scelrotiorum, Phytophthora capsici and Pythium ultimum, but it didn't inhibit the growth of Fusarium oxysprum and Fusarium solani. C. violaceum strain C-61 suppressed damping-off of eggplant caused by R. solani. Populations of the chitinolytic bacteria such as Aeromonas hydrophila, Serratia marcescens, Aeromonas caviae, Chromobacterium violaceum strain C-61 and Chromobacterium violaceum strain C-72 introduced into R. solani-infested soil were continuously decreased until 20 days after treatment, but their populations except A. caviae were not changed significantly and maintained over 5$\times$104 CFU per g of soil thereafter.

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Antimicrobial effects of curcumin against pathogenic bacteria in fish (어류의 병원성 세균에 대한 curcumin의 항균효과)

  • Heo, Gang-Joon;Kang, Jin-Hui;Shin, Gee-Wook
    • Korean Journal of Veterinary Service
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    • v.36 no.4
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    • pp.297-301
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    • 2013
  • The present study was to investigate anti-microbial effects of curcumin on major bacterial pathogens for farmed fish, such as Aeromonas hydrophila, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida, Edwardsiella tarda, Vibrio vulnificus, V. paraheamolyticus using disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. In disc diffusion test, curcumin exhibited concentration-dependent antimicrobial activities to all bacteria pathogens used in the study. Antimicrobial effects of curcumin was found differently depending on bacterial species when determined by MIC or MBC tests. For examples, E. tarda and A. hydrophila was respectively the most sensitive bacterium for bacteriostatic and bacteriocidal effect of curcumin. Collectively, curcumin could be a potential natural drug for controlling pathogenic bacteria in the aquaculture industry.

Purification and Characterization of Extracellular Temperature-Stable Serine Protease from Aeromonas hydrophila

  • Cho, Soo-Jin;Park, Jong-Ho;Park, Seong-Joo;Lim, Jong-Soon;Kim, Eung-Ho;Cho, Yeon-Jae;Shin, Kwang-Soo
    • Journal of Microbiology
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    • v.41 no.3
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    • pp.207-211
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    • 2003
  • Extracellular protease, from Aeromonas hydrophila Ni 39, was purified 16.7-fold to electrophoretic homogeneity with an overall yield of 19.9%, through a purification procedure of acetone precipitation, and Q Sepharose and Sephacryl S-200 chromatographies. The isoelectric point of the enzyme was 6.0 and the molecular mass, as determined by Sephacryl S-200 HR chromatography, was found to be about 102 kDa. SDS/PAGE revealed that the enzyme consisted of two subunits, with molecular masses of 65.9 kDa. Under standard assay conditions, the apparent $K_{m}$ value of the enzyme toward casein was 0.32 mg/ml. About 90% of the proteolytic activity remained after heating at 60$^{\circ}C$ for 30 min. The highest rate of azocasein hydrolysis for the enzyme was reached at 60$^{\circ}C$, and the optimum pH of the enzyme was 9.0. The enzyme was inhibited by the serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), by about 87.9%, but not by E64, EDTA, pepstatin or 1,10-phenanthroline. The enzyme activity was inhibited slightly by Ca$\^$2+/, Mg$\^$2+/ and Zn/supb 2+/ ions.

Isolation and Identification of Pathogenic Microorganisms from Soybean Sprouts

  • Kim, Hye-Jung;Koo, Kyoung-Mo;Kim, Gi-Nahm;Lee, Dong-Sun;Paik, Hyun-Dong
    • Preventive Nutrition and Food Science
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    • v.7 no.3
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    • pp.305-309
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    • 2002
  • Raw soybean sprouts were tested for contamination with the following bacteria which have potential for pathogenesis or food spoilage : Salmonella spp., Escherichia coli O157:H7, Yersinia enterocolitica, Vibrio parahae-molyticus, Aeromonas hydrophila, Plesidomonas shigeloides, Pseudomonas aeruginosa, Staphylococcus aureus, Lis-teria monocytogenes, Bacillus cereus, Clostridium perfringens, Campylobacter jejuni, Erwinia spp., and Fusarium spp. Three of the above strains were isolated from the sprouts, and identified by morphological and biochemical methods including an API kit and ATB automated identification system. The isolate cultured in Cereus selective agar, a selective medium, was a Gram-positive, rod shaped, anaerobic spore former. The biochemical and culture tests revealed the following characteristics: catalase-positive, no growth on Simmon's citrate, NO₂ production and requirement of arginine for growth; the ATB automated identification system gave 99.8 % agreement for the identification of Bacillus cereus to the species level. The isolate cultured in Macconkey agar selective medium was Gram-negative, rod shaped and a gas former; the ATB-system gave 99.9% agreement for the identification of Aeromonas hydrophila to the species level. The isolate found in Pseudomonas isolation agar was Gram-negative, rod shaped, cytochrome oxidase-positive, a reducer of nitrates to nitrogen, and pyocyanin producer; the ATB-system gave 99.9 % agreement for the identification of Pseudomonas aeruginosa to the species level. These results indicate that the three bacteria species present in the soybean sprouts were Bacillus cereus, Aero-monas hydrophila, and Pseudomonas aeruginosa. Salmonella spp., Escherichia coli O157:H7, and Yersinia enter-ocolitica, which are associated with serious disease in humans, were not isolated from soybean sprouts examined in this study.

Low Concentrated Nitrogen-Phosphate Removal of 4 Strains of Marine Bacteria Applied to Ceramic Media (세라믹 담체에 적용된 해양박테리아 4종의 저농도 질소-인 제거)

  • Lee, Gunsup;Kim, SoJung;Chung, Youngjae;Kim, Dongguin;Lee, Sang-Seob;Auh, Chung-Kyoon;Lee, Taek-Kyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.10
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    • pp.4910-4916
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    • 2012
  • Changes of low concentrated nitrogen-phosphate removal efficiency were investigated in 4 strains of marine bacteria applied to ceramic media. Marine bacteria were isolated and identified from Gwangyang bay. Growth rates and removal efficiencies of $NH_3$-N of 4 strains of marine bacteria applied to ceramic media were increased approximately 3 fold and over 30% than control group, respectively. A. hydrophila and P. diminuta had highest ${NO_3}^-$-N and phosphate removal efficiencies, respectively. This results showed that ceramic media is very nice material for improvement of nitrogen-phosphate removal efficiency and isolated marine bacteria may be useful to control nitrogen-phosphate at low concentration in field.