• Food Science and Preservation
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• v.11 no.4
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• pp.522-529
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• 2004

In the grilled fish paste stored at $5^{\circ}C$, the total aerobic bacterial counts were effectively reduced by 2.5 kGy or more. In the samples stored at $30^{\circ}C$, the total aerobic bacterial counts of the samples irradiated at 7.5 kGy were below to the limit of detection (2 log CFU/g). The TBA values of the irradiated samples were considerably higher than those of the controls but not proportional to the irradiation dose. It is apparent that an irradiation treatment causes very little textural degradation and the sensorial quality of the sample was maintained by an irradiation at 7.5 kGy or more.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1005-1011
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• 2005

Widespread distributions of repetitive DNA elements in bacteria genomes are useful for analysis of genomes and should be exploited to differentiate food-borne pathogenic bacteria among and within species. Enterobacterial repetitive intergenic consensus (ERIC) sequence has been used for ERIC-PCR genomic fingerprinting to identify and differentiate bacterial strains from various environmental sources. ERIC-PCH genomic fingerprinting was applied to detect and differentiate four major Gram-negative food-borne bacterial pathogens, Esherichia coli, Salmonella, Shigella, and Vibrio. Target DNA fragments of pathogens were amplified by ERIC-PCR reactions. Dendrograms of subsequent PCR fingerprinting patterns for each strain were constructed, through which relative similarity coefficients or genetic distances between different strains were obtained numerically. Numerical comparisons revealed ERIC-PCR genotyping is effective for differentiation of strains among and within species of food-borne bacterial pathogens, showing ERIC-PCR fingerprinting methods can be utilized to differentiate isolates from outbreak and to determine their clonal relationships among outbreaks.

• Journal of Applied Biological Chemistry
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• v.48 no.3
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• pp.133-137
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• 2005

In vitro antimutagenicity of Bacillus natto islolated from Natto, Japanese traditional fermented food, was investigated using umu-test. Mutagenicity of S9-activated metabolites of Trp-P-2 and IQ for Salmonella typhimurium TA 1535/pSK1002 was remarkably inhibited by addition of bacterial cells and their cytoplasmic fraction. Desmutagenicity by cytoplasmic fraction increased with increasing concentration of the fraction. Bioantimutagenic effect of cytoplasm on Salmonella typhimurium SD-100 did not show bioantimutagenic activity against mutated bacterial cells induced by Trp-P-2. Cytoplasmic fraction exhibited 17% bioantimutagenicity due to desmutation caused by IQ.

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.277-280
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• 1997

The effects of acetic acid (AA) on aerobic plate counts (APC), gram-negative bacterial counts (GNC), and generation time (GT) in chicken wings stored at 4* were assessed. Chicken wings were treated with 0.5-1.5% (v/v) AA at exposure times of 5 min. Treatments of AA for 5 min significantly (P<0.05) reduced aerobic plate counts (APC) and gram-negative bacterial counts (GNC) on the surface of chicken wings for 8 days, respectively. After 4 days of storage, treatments of 1.0% AA and 1.5% AA for 5 min completely (P<0.05) inhibited APC and GNC compared to initial controls. Based on these results, treatments of 1.0% AA and 1.5% AA for 5 min prolonged the microbiological shelf-life for 8 days compared to those of 0.5% AA and the controls. All treatments of AA increased the lag phase and GT of aerobic microorganisma.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.488-492
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• 1998

This study was performed to investigate the influcence of various dietary fiber sources in Korea for activities of bacterial enzymes (${\beta}$-glucosidase, ${\beta}$-glucuronidase) and amounts of putrefactive product (indole) in aged rats. ${\beta}$-Glucosidase activity in the intestinal content was significantly lower in the seamustard 15% group than in other groups whereas the activity of ${\beta}$-glucuronidase was higher in the mugwort 15% group than other experimental groups. The amount of indole and pH in the intestinal content of aged rats were significantly lower in mugwort groups than in other groups.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1542-1546
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• 2018

Bacterial canker in kiwifruit is caused by Pseudomonas syringae pv. actinidiae (Psa). In this study, the bacteriophage PPPL-1 effective against Psa was characterized. Belonging to the Podoviridae family, PPPL-1 was effective against most Psa strains as well as most Pseudomonas syringae pathovars. PPPL-1 carries a 41,149-bp genome with 49 protein coding sequences and is homologous to the previously reported phiPSA2 bacteriophage. The lytic activity of PPPL-1 was stable up to $40^{\circ}C$, within a range of pH 3-11 and under 365 nm UV light. These results indicate that the bacteriophage PPPL-1 might be useful to control Psa in the kiwifruit field.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1685-1689
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• 2014

Baeyer-Villiger (BV) oxidation of cyclohexanone to ${\varepsilon}$-caprolactone in a microbial system expressing cyclohexanone monooxygenase (CHMO) can be influenced by not only the efficient regeneration of NADPH but also a sufficient supply of oxygen. In this study, the bacterial hemoglobin gene from Vitreoscilla stercoraria (vhb) was introduced into the recombinant Escherichia coli expressing CHMO to investigate the effects of an oxygen-carrying protein on microbial BV oxidation of cyclohexanone. Coexpression of Vhb allowed the recombinant E. coli strain to produce a maximum ${\varepsilon}$-caprolactone concentration of 15.7 g/l in a fed-batch BV oxidation of cyclohexanone, which corresponded to a 43% improvement compared with the control strain expressing CHMO only under the same conditions.

• The Korean Journal of Food And Nutrition
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• v.3 no.1
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• pp.13-22
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• 1990

Nangmyun-broth was collected as samples from 25 common restaurants in Bucheon to examine it's sanitary condition. The main course of bacterial contamination was persuited for it's sanitary improvement. Bacterial count in summer sample was not greatly different from that in winter, resulting in total count 1.7$\times$10i1m1, lactic acid bacteria 8.7$\times$106/ml, coliform group 1 2$\times$105/ml, Staphylococcus aureus 6.5$\times$102/ml. Bacterial contamination occurred remarkably with the use of storage barrel in which remnent Nangmyun-broth was still resting, because the remnant Nangmyun-broth contained high level of bacteria Good santary condition in Nangmyun-broth was obtained by the use of clean barrel which had been washed with tap water or sterilizied with steam before filling fresh Nangmyun -broth for cold storage. The growth of Escherichia coli and Staphylococcus aureus was inhibited in the presence of acetic acid(0.01~0.05%) or mustart(0.1~0.5%)

• Journal of Food Hygiene and Safety
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• v.11 no.4
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• pp.227-234
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• 1996

This study was designed to characterize endotoxin-induced prostaglandin production in primary cultured rat vascular smooth muscle cells (VSMC). The time course for prostaglandin synthesis in lipopolysaccharide (LPS)-stimulated VSMC showed that the maximum production was reached in 12 hours. LPS induced prostaglandin H2 synthase (PGHS) activity in VSMC and the time course profile in the changes of PGHS activity paralleled that of total prostaglandin production. Differential treatment showed that 4 hours' exposure to LPS was enough for the maximum effect on the prostaglandin production and this effect was completely inhibited by the co-treatment of actinomycin D, a transcription inhibitor. These results suggest that LPS effect might be determined within 4 hours. Actinomycin D increased PGHS activity without affecting prostaglandin production if added 4 hours after LPS treatment. On the other hand, cyclogeximide, a translation inhibitor, augmented LPS-induced prostaglandin production if treated during first four hours, but it inhibited LPS-induced PGHS activity regardless of treatment schedule. These results suggest the existence of multiple regulating mechanisms in the LPS-induced prostaglandin synthesis.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2112-2118
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• 2017

Leuconostoc mesenteroides is used as a starter to produce high-quality kimchi products. In this study, an efficient and economical cabbage juice medium (CJM) was developed by process optimization of cabbage extraction and pasteurization and by compositional supplementation of various lacking nutrients. The pasteurized cabbage juice was determined to be a good medium candidate to cultivate L. mesenteroides, showing maximal cell numbers ($9.85{\times}10^8CFU/ml$) after 24 h. Addition of sucrose and yeast extract with soy peptone resulted in increment of bacterial cell counts in CJM, showing the supplementing effect of the lacking nutrients. Furthermore, addition of shell powder gave a protective effect on bacterial cells by preventing pH decline and organic acid accumulation in CJM, resulting in a 2-fold increase of bacterial counts. The optimized composition of CJM was 70% cabbage juice diluted with water, 0.5% (w/v) sucrose, 1% (w/v) yeast extract, 1% (w/v) soy peptone, and 1.5% (w/v) ark shell powder. The CJM developed in this study was able to yield a comparable level of bacterial counts with MRS medium and reduced the cost by almost 10-fold.