• Food Science and Preservation
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• v.10 no.4
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• pp.554-559
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• 2003

The optimal culture conditions on bacteriocin producing of Lactobacillus sp. FF-3 isolated from Korean Dongchimi, were studied for enhancing its production with regard to environmental and nutritional factors. The optimal cultivation time, initial pH and temperature were 21 hours, pH 7.0 and 30∼37$^{\circ}C$ respectively. Optimal compositions of culture medium for bacteriocin production were glucose 3% as carbon source, tryptone 4% as nitrogen source, and manganese sulfate 0.005% as inorganic salt with other basal components. The maximum antimicrobial activity was 484 BU/mL under the optimal culture condition.

• Journal of Microbiology and Biotechnology
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• v.7 no.1
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• pp.75-80
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• 1997

An ethanolic fermentation process was developed for preparing Doenjang with high ethanol. Higher and efficient viable cell production of salt-tolerant ethanolic yeast is a prerequisite for the successful commercial-scale process of ethanol production during Doenjang fermentation. Culture conditions of salt-tolerant yeast, S. cerevisiae KFCC 10823, was studied in terms of the effect of several environmental and nutritional factors. Viable cell numbers were the highest in a medium containing the following components per liter of water: soysauce, 300ml; dextrose, 50 g; beef extract, 5 g; yeast extract, 5 g; $KH_2PO_4$, 5 g; NaCl, 50 g. The optimal culture conditions of S. cerevisiae KFCC 10823 were pH 5.5, $25^{\circ}C$, 200 rpm and 0.5 vvm. Yeast viability during batch fermentation was gradually decreased to a level less than $90{\%}$ after 35 hours. The maximum cell number was $2.2{\times}10_7$ cells/ml at the optimal condition. Doenjang prepared with ethanolic yeast was ripened after 45 days at $30^{\circ}C$. This Doenjang contains 470 mg% of amino nitrogen and 2.5% ethanol. The shelf-life at $30^{\circ}C$ was theoretically estimated as 444 days.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.179-184
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• 2010

Escherichia coli O157:H7 is a food-borne pathogen that causes bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). We compared three selective media and evaluated the performance of immunomagnetic separation (IMS) for the detection of low levels of E. coli O157:H7 in ground beef and radish sprouts with different levels of background flora. Bulk food samples (500 g for each trial) were artificially inoculated with nalidixic acid-resistant E. coli O157:H7 at the lowest dose that would generate 20 partial-positive samples of 25 g each. All samples were homogenized in mTSB (225 mL) and incubated overnight at $37^{\circ}C$. IMS was performed using the enriched mTSB samples (1 mL) along with conventional spreads plated onto three different selective media: Sorbitol MacConkey agar (SMAC), Sorbitol MacConkey agar with cefixime and tellulite (CT-SMAC), and Sorbitol MacConkey agar with nalidixic acid (NAL-SMAC) as the gold standard. Two suspicious colonies from each medium were selected and confirmed usinga serological test after transfer to tryptic soy broth with yeast extract (TSAYE). CT-SMAC was better than SMAC for detecting E. coli O157:H7 in all food types. Although there was no statistical difference in the number of positive samples when using IMS vs. non-IMS techniques, more positive samples were detected when IMS was used in both ground beef and radish sprouts. It appears that the improvement was more significant in radish sprouts, which had a higher level of background flora than ground beef. The results also suggest that the combination of CT-SMAC and IMS is sufficient to recover low levels of E. coli O157:H7 in high background flora food samples.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.959-963
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• 2001

To investigate the antimicrobial effects of Scutellariae Radix extract against L.monocytogenes from foods, L. monocytogenes strains isolated from livestock, processed food from meat and milk, and frozen foods, were examined for their sensitivity to Scutellariae Radix extract. 30 L. monocytogenes strains were isolated from total 178 samples(16.9%); 13(14.0%) strains from beef 6(20.7%) strains from pork, 9(39.2%) strains from chicken and 2 (16.7%) strains from frozen foods but was not found from processed products, The serotypes of isolated L.monocytogenes were serotype O-1 strains (23, 76.7%) and serotype O-4 strains(7, 23.3%) on antisera agglutination test. The growth curves of isolates were shown lag phase, logarithmic phase, stationary phase and death phase as typical sigmoid curve on the preservative-free hams. After 6 hours. Scutellariae Radix extract contain group differ from control group on preservative-free ham samples, and the isolates were inhibited in more than 1000 ppm Scutellariae Radix extract on the inhibitory growth curve of L.monocytogenes. The mor-phological changes were observed by transmission electron microscope and the microbial cells membrane was destroyed by Scutellariae Radix extract.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.722-730
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• 2016

The carcass traits and meat quality of Hanwoo (Korean native cattle) whose diets were supplemented with direct-fed microbial (DFM) and pine cone extract (PCE) were evaluated. Twenty head of Hanwoo steers were divided equally into four groups and for a period of 6 months were given different diets: One group was fed a basal diet as control (CON), the other three groups were fed a basal diet supplemented with DFM-1%, DFM+PCE-1% and DFM+PEC-3%, respectively. DFM+PCE3% diet resulted the lowest carcass quality grade. The loins of DFM-1% contained higher moisture and lower fat than did the loins from the CON group. The crude protein content of DFM+PCE-3% group was significantly higher than that of the other groups. The water holding capacity and Warner-Bratzler shear force of the DFM+PCE-1% and 3% groups were lower than those of the CON and DFM-1% groups. The DFM-1% and 3% groups contained lower saturated fatty acid, higher unsaturated fatty acid, mono-unsaturated fatty acid, and poly-unsaturated fatty acid than did CON and DFM+PCE 1% group. Moreover, the n6:n3 ratios of DFM-1% and DFM+PCE-1% and 3% groups were slightly lower than that of the CON group. Thus we concluded that DFM and PCE supplementation resulted healthier Hanwoo beef with lower fat content and n6:n3 ratio.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.232-237
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• 1994

Microorganism producing glutaryl 7-aminodeacetoxycephalosporanic acid (GL-7-ADCA) acylase was screened from soil. The microorganism was identified as Alcaligenes sp. J-421 by its morphology and biochemical properties. Cultural conditions of Alcaligenes sp. J-421 were investigated for the production of GL-7-ADCA acylase. Optimum medium composition was 1% glucose, 1% beef extract, 0.5% yeast extract, 0.2% monosodium L-glutamate, 0.1% glutaric acid, 0.2% NaCl, 0.5% $K_2$ $HPO_4$, and 0.05% $CuSO _4{\cdot}5H_2O$. Optimum cultivation conditions for the production of the enzyme in 5 l jar fermentor were $37^{\circ}C$, tip speed 300 rpm, aeration 1 vvm. Optimum reaction pH of the enzyme was 8.0 and the enzyme was stable at pH7.0-11.0.

• Korean Journal of Microbiology
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• v.14 no.1
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• pp.8-16
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• 1976

About 600 strains of bacteria which can utilize methanol as the sole source of carbon were isolated from natrual sources, and their ability to produce amino acids on the medium containing methanol as the sole source of carbon was tested by paper chromatography, by which 3 strains were screened by virtue of their relatively shperior amino acid production. These were tentatively identified as follows ; one strain belonged to the genus methylomonas, while the remaining two were members of the genus Hyphomicrobium. Further studies on their growth characteristics were carried out with relation to amino acid production. According to these experiments, the following results were obtained. 1) No vitamin added was effective for the growth enhancement. 2) Optimum initial concnetration of methanol was proved to be one per cent (v/v), and no conspicuous effect of feeding methanol on the growth of these bacteria ould be observed, provide that the initial methanol concentration was controlled to 1 per cent. 3) Among the nitrogen sources tested, 0.1 per cent of ${(NH_4)}_2SO_4$ enabled the best growth. 4) Addition of 0.001 per cent $MgSO_4.$ $7H_2O$ largely increased the growth of all three strains. Other metal ions tested were either not effective or strongly inhibitory for the growth. 5) Addition of 0.1 per cent each of yeast extract, corn steep liquor, beef extract, and peptone also increased the growth markedly. 6) About $75{\mu}$g/ml of alanine could be obtained finally after 64 hr culture of Hypm. A on the medium lcontaining 0.1 per cent yeast extract and 1 percent methanol. Approximately $40.{\mu}$g/ml of glutamic acid by Hypm. GA and $43.{\mu}$g/ml of alanine by Mtlm. A were produced at the same culture conditions.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.119-121
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• 1995

쇠고기를 양념하여 구워서 조리식품으로 만들 때 사용하는 부가재료 중 생강이 고기에 미치는 영향을 연구한 결과 다음과 같은 것을 알 수 있었다. \circled1고기를 재울때 소금을 넣지 않고 생강즙을 0.5~l.0%까지 넣어 자작하니 재워두었다가 구운 고기는 20~30%까지 부드럽게 개선되었고 소금을 2% 첨가하고 생강즙을 넣은 고기는 35~45%까지 부드러워 졌다. \circled7 생강즙은 실험결과 고기의 산패를 늦추어 주었고 생강즙을 넣어 조리해서 Saran-Wrap을 가지고 2겹으로 포장해서 보관하거나 Vacuum처리하면 보존기간이 길게 되었다. \circled3생강즙은고기의 질을 연하게 하였고 특히 진공포장을 하지 않고도 조리식품으로 만들어진 제품으로 사용하기가 매우 편리할 것으로 생각된다.

• Microbiology and Biotechnology Letters
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• v.28 no.6
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• pp.334-340
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• 2000

In order to select multifunctional powerful antagonistic biocontrol agent against red-pepper rotting fungi Phytophthora capsici, we isolated an indigenous antagonistic bacterium which produces antifungal substances and siderophores from a local soil of Kyongju, Korea. The isolated strain was identified as Pseudomonas fluorescens biotype F. The antibiotic produced from P. fluorescens 2112 inhibited hyphae growth and the zoospore germination of Phytophthora capsici. The favorable carbon, nitrogen source and salts for the production of antibiotic from P. fluorescens 2112 were glycerol, beef extract and LiCi at 1.0%, 0.5% and 5 mM, respectively. And antagonistic activity of P. fluorescens 2112 was confirmed against P. capsici in vivo.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.75-80
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• 1995

Dextranase produced by Flavobacterium multivorum HL-1 isolated from soil were characterized. Optimum growth condition for the production of the enzyme by the strain appeared to be at the 1.0% concentration of dextran. When NH$_{4}$N0$_{3}$ and beef extract was added to the culture media, the enzyme activity increased upto 570 and 680 units per ml respectively, and other nitrogen sources did not increase the activity. Urea, casamino acid, (NH$_{4}$)$_{2}$SO$_{4}$ and KNO$_{3}$ inhibited the activity. In the presence of Mg^{2+} in culture media, the enzyme activity increased 124%, but its activity was inhibited in the presences of Ca$^{2+}$, Co2$^{2+}$, Hg^{2+} and Zn$^{2+}$ . The optimum temperature for the enzyme activity was 45-55$\CIRC$C . In the ranges of pH 4 to 10, the activity of the enzyme appeared approximately similar.