• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.184-188
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• 2002

A bacteriocin producing microorganism, which inhibits the growth of Lactobacillus sake, was screened and isolated from Kimchi. This microorganism was identified and named as Lactobacillus sp. Oh-B3, The maximum amount of bacteriocin was produced when the isolated microorganism was cultured in MRS media(pH 8.0) for 24 hours at 25℃. The bacteriocin from the isolated microorganism was purified through ammonium sulfate precipitation, dialysis and ultrafiltration. The bacteriocin was stable on the wide pH range of 2.0-9.0, and showed antimicrobial activity on some of gram positive bacteria, not on gram negative. The antimicrobial activity of bacteriocin was mostly removed by treatment of proteolytic enzymes. But, the bacteriocin was very stable on the heat treatment, and more than 50％ of activity was remained at autoclaving. The action mode of the bacteriocin showed bacteriocidal pattern, being same as that of general bacteriocins.

• Korean Journal of Organic Agriculture
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• v.13 no.2
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• pp.161-173
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• 2005

This study was carried out to clarify the effects of antifungal bacterial strains isolated from the greenhouse soil grown strawberry plants on the growth inhibition of plant pathogen, gray mold (Botrytis cinerea) infected in strawberry plants in Damyang and Jangheung districts. Antagonistic bacterial strains were isolated and investigated into the antagonistic activity against gray mold. Screened ten bacterial strains which strongly inhibited Botrytis cinerea were isolated from the greenhouse grown strawberry plants, and the best antifungal microorganism designated as SB 143 was finally selected. Antifungal bacterial strain SB 143 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. Bacillus sp. SB 143 showed 59.4% of antifungal activity against Botrytis cinerea. By the bacterialization of culture broth and heated filtrates of culture broth, Bacillus sp. SB 143 showed 93.1% and 32.1% of antagonistic activity against Botrytis cinerea.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.405-409
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• 2003

To study the tolerant capacity of anaerobic granular sludge (AGS) to oxygen using semi -dynamic batch experiment, the aerating time, pH of the basal media, reductive inorganic materials, microorganism, and microorganism metabolite were investigated. When the aerating time was higher or lower than 0.5 h, the producing gas activity of sludge was lower than that of the control. The oxygen tolerance of the experimental sludge was the highest at the initial pH 7.2. The producing gas activity of sludge I was higher than that of sludge II. And storage at $4^{\circ}C$ can low the lose of the oxygen tolerance capacity of granular sludge. The producing gas activity of sludge was the highest when KI was added. The growth of aerobic microorganisms and some metabolite could increase the producing gas activity of granular sludge.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1030-1034
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• 2009

A fermenting microorganism involved in formation of ortho-dihydroxyisoflavones (ODIs) during aging of doenjang (Korean fermented soybean paste) has been investigated. Microorganisms in ODI-containing doenjang were isolated by cultivating on yeast mold (YM) agar medium containing 0-7% NaCl. ODI formation of the isolated strains was examined by gas chromatography/mass spectrometry (GC/MS) analysis after cultivation in modified YM broth or soybean extract medium. An ODI-producing microbe was identified as Bacillus subtilis HS-1 based on 16S rRNA gene sequence analysis. The strain has produced 8-hydroxydaidzein as a major product during growth in the modified YM broth or soybean extract medium. Therefore, it was concluded that one of the microorganisms involved in the formation of ODIs in doenjang was B. subtilis HS-1.

• Journal of Ginseng Research
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• v.17 no.2
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• pp.148-152
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• 1993

One kind of microorganism was isolated and identified from Korean fresh, white and red ginseng, and the effect of a preservative, sodium benzoate on the microorganism and its thermal resistant propertues were studied. The results obtained were as follows. The predominant strain on ginseng and ginseng products was identified as Penicillium sp. The strain showed perithecium structure producing ascospores. The growth of the strain was slightly inhibited at 0.0571 concentration of sodium benzoate. The minimal inhibitory concentration (MIC) of sodium benzoate against the strain was 0.26%. The D value of the strain at 56, 59, $62^{\circ}C$ were 9.9, 5.0 and 4.5 min, respectively.

• Food Science and Preservation
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• v.3 no.2
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• pp.187-193
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• 1996

To investigate the antimicrobial activities and effect of grapefruit seed extract(GFSE) on the physiological function of microorganism, antimicrobial activity, fatty acids of bacterial cell lipid and amino acids of bacterial cell protein were measured. The change of cell morphotype was observed by transmission electron microscope. GFSE was very stable on the wide range temperture and pH. The growth rate of E. coli and B. suvtilis were decreased above 40ppm GFSE There fore, minimum inhibitory concentration (MIC) of the E. coli and B. subtilis to GFSE were determined around 40ppm. In the change of fatty acids quantities, hexadecanoate was significantly decreased on the treatment compared with control in case of E. coli, whereas tridecanoate was not detected in case of B. subtilis. In the change of amino acids quantities, alanine, glutamic acid, glycine, lysine were decreased on the treatment compared with control in case of E. coli and B. subtilis Transmission electron microsgraphs(TEM) showed the microbial cells were destroyed by GFSE.

• Journal of Life Science
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• v.10 no.2
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• pp.196-201
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• 2000

The production of tetrodotoxin (TTX) using Vibrio sp. YE-101, a novel marine microorganism isolated from the intestine of pufferfish, was investigated. Culture condition was optimized for the enhanced production of TTX using response surface methodology. The experimental sets of environmental conditions including pH, temperature and NaCl concentration were designed using central composite experimental design. The optimal conditions of pH, temperature and NaCl concentration were determined to be 8.1, 29.2℃, and 2.6% (w/v) respectively. The relative growth extent could be enhanced up to 80%, and final mouse unit (MU) value of TTX was also enhanced up to 87% by response surface optimization.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.6
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• pp.352-356
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• 2002

Aeration was found to affect the biological denitrification by Ochrobactrum authropi SY509. Although cell growth was vigorous under 1 vvm of aeration and an agitation speed of 400 rpm in a 3-L jar fermentor, almost no nitrate was removed. Yet under low agitation speeds (100, 200, and 300 rpm), denitrification occurred when the dissolved oxygen was exhausted shortly af-ter the inoculation of the microorganism. Ochrobactrum authropi SY509 was found to express highly active denitrifying enzymes under anaerobic conditions. The microorganism also synthesized denitrifying enzymes under aerobic conditions (1 vvm and 400 rpm), yet their activity was only 60% of the maximum level under anaerobic conditions and the nitrate removal efficiency was merely 15%. However, although the activities of the denitrifying enzymes were inhibited in the presence of oxygen, they were fully recovered when the conditions were switched to anaerobic conditions.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.120-124
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• 2010

This study was carried out to investigate interaction between mushroom mycelium and microorganisms in cotton waste media for the shelf cultivation of oyster mushroom. Two oyster mushroom farms was selected for this experiment. One was good mushroom farm (farmhouse I) and the other failed mushroom farm (farmhouse II). In farmhouse I, the inhibition microorganisms were higher toward the end of growth stage than the early stage, but the result of farmhouse II was opposite. Effects of the mycelium growth on plate culture showed same results on mushrooms as the earlier one. And the mycelium growth was influenced by secretory materials of microorganisms. Among of the isolates, Only few microorganism had inhibitory effects on either P. tolaasii or T. harzianum causing the disease of oyster mushrooms. But more microorganisms had inhibition effects on P. agarici.

• Journal of Mushroom
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• v.20 no.2
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• pp.55-60
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• 2022

This study was conducted to establish an appropriate period of use of sawdust spawn at low temperatures and a nutrient supplement medium for cultivation of Lentinula edodes 'Hwadam'. Of the nutrient supplements, the total yield of rice bran (5%) + corn flour (5%) treatments were 673.3 g, which was higher than rice bran (551.6 g) and wheat bran (546.7 g) treatments, respectively. As shown by the growth of Lentinula edodes 'hwadam' during to the sawdust spawn storage period (at 4℃), the period of spawn running, browning, fruiting body formation, and development was 27 d, 81 d, 5 d, and 11-13 d, respectively, regardless of the length of the storage period at 4 ℃. After 3 months of storage of sawdust spawn, the number of fruiting bodies and yield decreased as the storage period increased. Therefore, the period of use of sawdust spawn (at 4 ℃) for the stable production of fruiting bodies of Lentinula edodes 'Hwadam' was a maximum of 3 months.