• Korean Journal of Veterinary Service
• /
• v.38 no.2
• /
• pp.65-70
• /
• 2015

The present study was to investigate in vitro antimicrobial effects of propolis against six different fish bacterial pathogens, Aeromonas hydrophila, Edwardsiella tarda, Vibrio vulnificus, V. parahaemolyticus, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida) using minimum inhibitory concentration (MIC) and minimum bacteriocidal concentration (MBC) tests. In the results, propolis exhibited antimicrobial activity against all bacteria used in the present study, but there was no marked difference in bacterial species except Vibrio species. Collectively, propolis was thought to be an usefulness antimicrobial substance for controlling bacterial diseases in the fish industry.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.735-738
• /
• 2001

Metabolically engineered Escherichia coli strains harboring a plasmid containing a novel artificial polyhydroxyalkanoate (PHA) operon consisting of the Aeromonas PHA biosynthesis related genes and Ralstonia eutropha reductase gene were developed for the production of poly(3-hydroxybutyrate-co-hydroxyhexanoate) [P(3HB-co-3HHx)] from dodecanoic acid. By applying stepwise reduction of dissolved oxygen concentration (DOC) during the fermentation, the final dry cell weight, PHA concentration, and PHA content of 79 g/L, 21.5 g/L, and 27.2 wt%, respectively, were obtained in 40.8 h, which resulted in the PHA productivity of 0.53 g/L/h. The 3HHx fraction slowly increased during the fed-batch culture to reach a final value of 10.8 mol%. The 3HHx fraction in the copolymer could be increased by three fold when the Aeromonas hydrophila orfl gene was co-expressed with the PHA biosynthesis genes.

• Journal of Microbiology and Biotechnology
• /
• v.6 no.6
• /
• pp.461-467
• /
• 1996

Four strains of lactic acid bacteria (LAB), that lower the pH of sausage $\leq$ 4.2 within 24 h of incubation at $37^{\circ}C$, were screened from 57 bacteriocin producing LAB which were isolated from kajamie shikhae and natural fermented sausages. The proteinaceous nature of the bacteriocin was confirmed by losing antimicrobial activity after pronase treatment. Inhibitory activity against pathogens, times of bacteriocin production and sensory tests were compared between 4 isolates and 3 commercial starters. Especially, strain NFS #8-1, screened from natural fermented sausage and identified as Pediococcus acidilactici, antagonized a large number of foodborne pathogens including Listeria monocytogenes, Aeromonas hydrophila, Bacillus cereus, Clostridium perfringens, Salmonella typhimurium and Staphylococcus aureus. Production of bacteriocin by strain NFS #8-1 was early in the growth phase (mid log phase) and its sensory acceptance was high. The feasibility of using strain NFS #8-1 as a starter for the production of microbiologically safe fermented sausage is envisaged.

• The Korean Journal of Ecology
• /
• v.12 no.2
• /
• pp.75-82
• /
• 1989

Bacterial strains which have excellent removal capacity of phosphate or reduction capacity of were isolated from waste water. Among isolated strains. WR8 and WR1 strains were showed goood efficiency in removal of phosphate and reduction of respectively. When each strain was cultivated in waste water, WR8 strain removed about 85% of phosphate and WR1 strain reduced about 85% of -N. By the result of investigation of morphological and physiological characteristics, WR8 was identified as Aeromonas hydrophila and WR1 as Klebsiella pneumoniae.

• Journal of environmental and Sanitary engineering
• /
• v.19 no.3 s.53
• /
• pp.22-30
• /
• 2004

The extract with the dilution of $50\%$ ethanol and treatment of $121^{\circ}C$ for 15min were inhibited highly the growth of staph aureus, Ent. cloacae, Sh. sonnei, A. hydrophila, b. subtilis, St. faecalis and L. casei. of food samples, red-bean dregs with addition of extact of smilax china. leaves or sorbic acid took the similar inhibition effect to microorganisms for the early storage days(1-3days). There was inhibited the growth of microorganisms in strawberry Juice added to 20m1 of $1\%$ extract solution for one storage day in comparison with no addition of smilax china L. Over all with growth inhibition capability to microorganisms and foods, it was believed that the effect and value as the natural food preservatives and the extracts like as this natural plant material took the food safety and it was capable to develop the natural food preservation.

• Bulletin of Food Technology
• /
• v.13 no.3
• /
• pp.3-16
• /
• 2000

신선 채소류 편의식품에 관련된 병원성 세균으로는 Listeria monocy togenes, Yersinia enterocolytica,A eromonas hydrophila 등이 포함된다. 이들 제품은 미생물(병원성 및 비병원성)을 감소시키거나 사멸시키기 위해 별도의 살균 또는 항균제재를 사용하지 않기 때문에 초기 원료에 존재하거나 혹은 가공 및 유통 과정에서 오염된 미생물이 제품에 그대로 존재할 수 있다. 따라서 이들 제품에서는 병원성 세균이 발견될 수도 있으며, 특히 냉장유통 중 온도조절이 불완전할 경우 그 가능성이 더욱 높아지므로 신선 편의식 채소류 제품에 대해서는 보다 철저한 위생관리가 필요하다. 이러한 측면에서 위해 요소 중점관리기법(Hazard Analysis Critical Control Point, HACCP)을 적용하면 미생물학적 안전성을 확보할수 있다. HACCP이란 특정 제품의 수확에서 소비까지 전 공정에 대해 위해 요소를 검토하고, 이를 조절하기 위한 특별한 수단을 규정하는 관리기법이다. 본 연구에서는 HACCP의 7가지 기본 원칙을 정리하여 실제 대파(green onion)의 최소가공 과정에 적용함으로서 미생물학적 안전성을 확보하고자 시도한 사례를 중심으로 검토하였다.

• Fisheries and Aquatic Sciences
• /
• v.18 no.4
• /
• pp.341-347
• /
• 2015

We evaluated the biological activities of five water extracts of tissue of the mottled anemone Urticina crassicornis. Most extracts exhibited broad-spectrum antimicrobial activity as determined by ultrasensitive radial diffusion assay (URDA) against gram-positive and -negative bacteria, including a fish pathogen, Aeromonas hydrophila, but no activity against fungi. The activity of the extracts was abolished by tryptic digestion, indicating that protein compounds were responsible for the antimicrobial activity. Furthermore, in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity assay, only the visceral tissue extract showed activity. However, no extract had hemolytic activity against human red blood cells. Consequently, this study suggests the water-soluble extract of mottled anemone to be a promising source of proteinaceous antimicrobial compounds that can be utilized for development of novel antibiotics.

• Journal of Microbiology
• /
• v.45 no.4
• /
• pp.297-304
• /
• 2007

The detection of virulence factors of Aeromonas is a key component in determining potential pathogenicity because these factors act multifunctionally and multifactorially. In this study water samples were collected from a trout farm on a seasonal basis, and diseased fish and Aeromonas species were isolated and identified. For rapid detection of six virulence factors of isolated Aeromonas, a hexaplex-polymerase chain reaction (hexaplex-PCR) assay was used. The detected virulence factors include aerolysin (aer), GCAT (gcat), serine protease (ser), nuclease (nuc) lipase (lip) and lateral flagella (laf). The dominant strain found in our isolates was Aeromonas sobria, and the dominant virulence factors were aer and nuc for all seasons. We confirmed that A. sobria and two of the virulence genes (aer and nuc) are related. We proposed a method by which one can identify the major strains of Aeromonas: A. hydrophila, A. sobria, A. caviae, and A. veronii, using hexaplex-PCR.

• Current Research on Agriculture and Life Sciences
• /
• v.30 no.2
• /
• pp.105-109
• /
• 2012

Blacken spoilage is one of the common problems during the cold storage of dried persimmon in Korea. We collected the spoiled dried persimmon in the refrigerator and classified them to 4 types depending on their appearances. Furthermore we isolated blacken spoilage inducing bacteria from type D of dried persimmons. Among the isolates we identified the seven blacken spoilage inducing bacteria. They are Aeromonas hydrophila DP1, Cedecea davisae DP2, Ewingella americana DP3, Flavimonas oryzihabitans DP4, Providencia rettgeri DP5, Providencia rustigianii DP6 and Serratia plymuthica DP7. Strains were identified based on their morphological, cultural and physiological properties. We also found that Ewingella americana DP3, Flavimonas oryzihabitans DP4 were the major blacken spoilage inducing bacteria during dried persimmon storage.

• Journal of Food Hygiene and Safety
• /
• v.16 no.2
• /
• pp.125-132
• /
• 2001

The present study was conducted to investigate biological degradability of phosphamidon and profenfos. In the biodegradation test of two pesticides by the modified river die-away method from May 20 to July 29, 1999, the biodegradation rate was determined in Nakdong (A) and Kumho(B) River. The residual percentages of phosphamidon were 74.9%, 68.8% and 62.7% in control, A and B samples 7 days after applicaton, respectively. Biodegradation constants and half-lives of phosphamidon were 25.1%, 21.9% and 11.9% in control, A and B samples 7 days after application. Biodegradation constants and half-lives of profenofos were 0.0005 and 58.4 days in A, 0.0013 and 21.6 days in B, respectively. The biodegradation rates of phosphamidon and profenofos were higher in the Kumho River (B) than in the Nackdong River(A). The strains of microorganisms for the degradation of phosphamidon and profenofos were identified as Klebsiella pneumoniae, Aeromonas hydrophila and Acinetobacter calcoaceticus, all Gram-negative bacteria. In order to identify biodegradate products, the extracts of cultivates were analyzed by GC/MS. The mass spectra of biodegradate roducts of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the biodegradate metabolites of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.