• Title/Summary/Keyword: bacterial growth

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탁주 발효에 대한 Nisin의 이용

  • Yoo, Jin-Young;Lee, Sung
    • Microbiology and Biotechnology Letters
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    • v.25 no.2
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    • pp.203-206
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    • 1997
  • Takju is a traditional alcoholic beverage that has been prepared by fermenting the cooked rice and Nuruk (Korean-style bran koji). During fermentation. bacterial contamination is a problem which inhibits the growth of yeast and thus lowers the ethanol production from starch of rice, and causes souring. Major contaminants were known to be gram-positive acid producers at the early stage of fermentation. This problem would be solved if the contaminated bacteria could be controlled. Nisin, a GRAS-grade preservative, was added at the level of 500 iu/g as it retards the growth of the gram-positive bacteria. It was possible to control acid and ethanol production during fermentation. This process increased the ethanol production by 2 % comparing with control.

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Aortic and Pulmograft Transplantation Utilizing Cryopreservation (초저온 냉동보관법을 이용한 동종판막 이식술에 대한 연구)

  • Song, Myeong-Geun;Lee, Dong-Sun
    • Journal of Chest Surgery
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    • v.23 no.4
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    • pp.622-639
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    • 1990
  • The use of aortic valve homograft has been developed since 1962 when Ross and Barratt - Boyes independently replaced a diseased aortic valve with an orthotopically inserted homograft valve. And also surgical treatment of complex congenital cardiac malformations utilizing homograft extracardiac conduit has been tried with better result than any other prosthetic material. The present study was undertaken to clarify the safety tissue viability, sterility, after following our protocol of procurement of heart, dissection of aortic and pulmonic homograft, sterilization, cryopreservation, thawing and dilution, and transplantation on experimental animal, sheep. Tissue viability of valve and great artery was assessed by tissue culture. Sterility was evaluated by bacterial and fungal culture. The method used was proven no deleterious effect on the integrity of the valve. Tissue culture of valve tissue before, and after cryopreservation process resulted that active fibroblast growth was observed from homograft sterilized with antibiotics. And culture of the transplanted homograft from sacrificed animal showed active fibroblast growth. Pathologic examination of implanted valve tissue from sacrificed sheep showed mild calcification and minor change, but there were moderate and severe calcification of wall of great arteries.

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Isolation of a Marine Bacterium Capable of Biodegrading Poly(butylene succinate)

  • Lee, Sang Jun;Park, Eun Hee;Han, Yun Hee;Kim, Young Ok;Park, Seong Wook
    • Fisheries and Aquatic Sciences
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    • v.16 no.1
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    • pp.41-44
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    • 2013
  • We developed a poly(butylene succinate) (PBS) indicator plate and isolated a marine bacterial colony capable of biodegrading PBS based on the appearance of a clear zone. Growth of the PBS-2 isolate was observed over 4 days of culture at $37^{\circ}C$ in PBS-tryptone basal liquid medium, but not in PBS-deprived control medium. The PBS-2 isolate was named Paenibacillus sp. PBS-2 based on 16S rDNA gene sequencing. The PBS-biodegrading marine bacterium isolated in this study will contribute to the effective management of PBS waste problems in marine environments.

Effect of Alcohol Treatment on Growth of Microorganisms Contaminated in Ginseng Powders (알콜처리가 인삼분말에 오염된 미생물의 성장에 미치는 영향)

  • 곽이성;장진규;주종재
    • Journal of Food Hygiene and Safety
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    • v.12 no.3
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    • pp.205-209
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    • 1997
  • Alcohol treatment was applied to ginseng powder for the improving hygienic quality of ginseng powder. A bacterial strain designated as GT5 was isolated from ginseng powder contaminated and was identified as Escherichia coli species by IMVIC test method. Ethanol used as alcohol, inhibited strongly the growth of coliforms in ginseng powder at the concentrations of 50 to 90%. Ethanol treatment also decreased numbers of total bacteria at the same concentrations. There was not significant changes in saponin of ginseng powder after treated with ethanol. However, ethanol treatment caused a decrease in Hunter's color L value and an increase in a and b values of ginseng powder. As a hygienic quality control of ginseng powder, ethanol treatment could be cosidered as an effective means for decontaminating microorganisms in ginseng powder.

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Transformation of Bacillus brevis P176-2 with Plasmid DNA by Electroporation (전기천공법에 의한 Bacillus brevis P176-2의 형질전환)

  • 채기수;엄경일
    • The Korean Journal of Food And Nutrition
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    • v.5 no.2
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    • pp.77-83
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    • 1992
  • The optimum conditions and mechanisms for the plasmid-mediated genetic transformation of intact cells of Bacillus brevis Pl76-2, an extracellular protein producing bacterium by electroporation were investigated. It was found that pUB110 Plasmid DNA can be introduced into intact bacterial cells by electroporation. The frequency of transformation by this electroporation system depended upon the initial electric field strength, the capacity of the electric discharge capacitor, growth stage, number of successive pulses and composition of electroporation buffer. It was effective for transformation that cells were harvested, washed and resuspended with HSM [7M HEPES(PH 7.4), 272mM sucrose, 1 mM MgCl2] electroporation buffer when cell growth was attained to 1.2 at OD660. A maximum frequency of transformation of 2.40$\times$104 transformants per$\mu$g plasmid DNA was obtained by two succesive Pulses with an initial electric field strength of 12.5kV/cm and with a capacitance of 7.3uF.

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Inhibitory Effect of Pentose on Biofilm Formation by Oral Bacteria

  • Lee, Young-Jong;Baek, Dong-Heon
    • International Journal of Oral Biology
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    • v.35 no.4
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    • pp.203-207
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    • 2010
  • A number of bacterial species coexist in oral cavities as a biofilm rather than a planktonic arrangement. By forming an oral biofilm with quorum sensing properties, microorganisms can develop a higher pathogenic potential and stronger resistance to the host immune system and antibiotics. Hence, the inhibition of biofilm formation has become a major research issue for the future prevention and treatment of oral diseases. In this study, we investigated the effects of pentose on biofilm formation and phenotypic changes using wild type oral bacteria obtained from healthy human saliva. D-ribose and D-arabinose were found to inhibit biofilm formation, but have no effects on the growth of each oral bacterium tested. Pentoses may thus be good candidate biofilm inhibitors without growth-inhibition activity and be employed for the future prevention or treatment of oral diseases.

Development and Characterization of Membrane for Local Delivery of Cephalexin

  • Shin, Sang-Chul;Oh, In-Joon;Cho, Seong-Jin
    • Archives of Pharmacal Research
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    • v.19 no.1
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    • pp.1-5
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    • 1996
  • Laminated films composed of drug-containing reservoir layer and drug-free membrane were prepared. Zero-order drug release with lag time was achieved by laminating drug-free film onto the reservoir layer, while burst effect was observed on cast-on film. The rate controlling membrane was either attached to or cast directly into the reservoir. The release rate was independent on the reservoir composition but dependent on the composition of rate-controlling membrane. In growth inhibitory test of cephalexin from Eudragit RS film to Streptococcus Mutans, the disk even after release test for 72 hours showed more bacterial growth inhibition than that of control. Permeation of drug through rat skin was proportional to the HPC fraction in the film. We could control the release of cephalexin from the film by changing the fraction of Eudragit RS, HPC and DEP content. Consequently, Eudragit RS/HPC film was found to be very effective system for local delivery of drugs.

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Properties of Enterococcus faecium isolated from the intestineof slaughting pigs (도축돈 장관에서 분리한 Enterococcus faeciurnab 특성)

  • Kim, In-doc;Ahn, Mi-hyun;Seok, Ho-bong
    • Korean Journal of Veterinary Research
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    • v.44 no.4
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    • pp.581-586
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    • 2004
  • The growth characteristics and the properties of the Enterococcus faecium (E. faecium) isolated from intestine of slaughting pig were examined in order to confirm whether it will be used practically as probiotics or not. E. faecium was identified by morphological and biochemical tests including of final confirming by API strep kit. Among 264 samples, 44 isolates (16.7%) of E. faecium were observed as an exellent growth as a range of $1{\times}10^7CFU/ml{\sim}3.3{\times}10^9CFU/ml$ in viable bacterial count on MRI medium. All isolates were shown non-haemolysis on the blood agar exception of 28 isolates shown ${\alpha}$-haemolysis and were identified as E. faecium by biochemical test using API strep enzyme kits. Eight strains (18.2%) were finally selected from which they were excellent sensitivity in showing of the acid-tolerance and the bile-tolerance in compare with reference strain.

Microbiological and Genotoxicological Safety of Gamma-Irradiated Chicken (감마선조사 닭고기의 미생물학적 및 유전독성학적 안전성 평가)

  • 곽희진;정차권;강일준
    • Korean journal of food and cookery science
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    • v.17 no.6
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    • pp.617-624
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    • 2001
  • Gamma irradiation (1-10 kGy) was applied to chicken for the evaluation of their microbiological safety and possible genotoxicity. In 3 kGy-irradiated sample, the growth of psychrophile was inhibited about 1.5 log cycles and no cells were recovered in total microbial counts. All kinds of contaminated microorganism were sterilized by 7 kGy-irradiation. Also, irradiation followed by freeze-storage at the same time was very effective in inhibiting bacterial growth. The genotoxicity of 10 kGy-irradiated chicken was evaluated by Salmonella Typhimurium reversion assay and in vivo micronucleus assay using mouse bone marrow cells. The results were negative in the bacterial reversion assay with S. Typhimurium TA98, TA100, TA1535, and TA1539. Clastogenic effects were not shown in vivo mouse micronucleus assay at 10 kGy-dose tested.

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Marketing of cleaned fresh ginseng and pre-packaging fumigation of 2-phenylethyl alcohol on ginseng storability (세척인삼 유통 현황과 포장전 2-phenylethyl Alcohol 훈증이 저장성에 미치는 영향)

  • Kim, Sun-Ik;Sung, Bong-Jae;Kim, Hyeon-Ho;Hwang, Yong-Soo
    • Korean Journal of Agricultural Science
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    • v.38 no.2
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    • pp.205-212
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    • 2011
  • The potential factors for quality loss of cleaned fresh ginseng and technology to be associated with the improvement of marketability through pre-packaging fumigation were examined. Major microorganisms isolated from fresh ginseng included Botrytis cinerea, and Erwinia sp. Others such as Cylindrocarpon sp., Fusarium spp., Pennicilium spp., Bacillus spp. were also found at relatively low frequency. The bacterial density of vacuum packaged fresh ginseng rapidly increased during simulated marketing. Little correlation between bacterial growth and package swelling was found. In order to improve packaging method of fresh ginseng, pre-packaging treatment of 2-phenylethyl alcohol (PE, 100 uL/L, 4 hr) was examined. The fumigation treatment effectively inhibited the growth of bacteria density and also effective on keeping firmness of ginseng root, especially in cortical portion. The internal gas compositions of plastic container packaged for ginseng were approximately ranged between 6 to 8% $O_2$and 3 to 4% $CO_2$. The $O_2$ level of fumigation treatment was lower than control whereas $CO_2$ level was higher. The upsurge of ethylene evolution I day after simulated marketing was found only in fumigation treatment but it returned to ordinary level at day 2. The sucrose content of 2-PE treatment was significantly reduced at 5 days after simulated marketing but reducing sugars like glucose and fructose remained at higher level. The difference in sugar levels was reduced after 10 days of simulated marketing. The decay of fresh ginseng began at the lateral or fine root, which is weak to physical damage, in general. The epidermis was more damaged. Plastic container packaging with PE fumigation could be an alternative to vacuum packaging, which allows an aerobic environment and prevents anaerobic respiration. Further study of pre-package fumigation is required to improve technology of fresh ginseng marketing.