• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.640-646
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• 1998

For the production of nonprotein $\alpha$-glucosidase inhibitor from the Streptomyces sp. NS15 strain, effects of initial optimum pH, nitrogen sources, carbon sources, cationic metal ions, agitation speed and aeration rate were investigated. Initial optimum pH of medium was 7.0. The most effective nitrogen and carbon sources were soybean meal 2.0%(w/v) and glucose 1.6%(w/v), respectively. The cationic metal ins had no stimulating effect on inhibitory activity of $\alpha$-glucosidase except Fe2+. Agitation speed and aeration rate were effective at 400rpm and 1vvm, respectively. In the jar-fermenter cultivation for 4 days under optimal culture conditions, the culture broth showed the inhibitory acitivity of 3,200units/ml, which is 25 times higher than that of basic medium (CYM) for porcine intestinal $\alpha$-glucosidase. The inhibitory activity of $\alpha$-glucosidase reached about 3,200units/ml after 4 days of cultivation and decreased gradually for a further two days.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.793-800
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• 2002

The mycolic acids and fatty acids of mycolic acid- containing bacteria in various types of fluids were analyzed using capillary gas chromatography and mass spectrometry. As model strains, Brevibacterium and Coryebacterium species, which have corynomycolic acids ill the range of $C_{32}C_{36}$ in the whole cell, were investigated. Optimized solvents extraction procedures for the mycolic acids and fatty acids from the culture fluids were: chloroform/methanol (1:2, v/v) as the first extraction solvents fur 4 h; and chlorofunuwater (1:1, v/v) as the second extraction solvents far 1 h. These conditions gave above 95% recovery yields fur mycolic acids from the culture fluids. The mycolic acid profile for the whole cells and the culture fluids were similar fur all the media tested. Thus, the procedure described here could be applied for the identification of mycolic acid-containing bacteria in fermentation broth or liquid from of foods.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.202-204
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• 2010

Inhibitory effect on tyrosinase activity and melanogenesis of the mycelia and mycelial culture broth of Macrolepiota procera were investigated. The methanol fraction of culture broth showed 56.6% of tyrosinase inhibitory activity and its IC50 was 8.78 mg/ml. Using Streptococcus bikiniensis for melanogenesis in vitro, the methanol extract of mycelia showed 94.0% inhibition of melanogenesis.

• Food Science and Preservation
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• v.8 no.2
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• pp.206-212
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• 2001

Water extract of green tea(GTW) and 70% ethanol extract of green tea(GTE) were prepared for the test of antibacterial activity. The sensitivity of Staphylococcus aureus and Salmonella typhimurium to the green tea extracts in various pH of culture broth was tested. Tryptic soy broth(TSB) containing 0∼2%(w/v) of green tea extracts was adjusted to pH 5.0∼7.0 and inoculated with 10$\^$5/∼10$\^$6/ cells/ml of each bacteria. The plate counting method and clear zone test were used to determine inhibitory effect of green tea extracts. Green tea extracts completely inhibited the growth of S. aureus at 0.5% level and bactercidal at 0.5∼1.0% level of GTW and GTE at pH 5.0∼7.0. Green tea extracts were bactercidal to S. typhimurium at 1.5∼2.0% level of GTW and 1.0∼2.0% level of GTE at pH 7.0. Sal. typhimurium was more resistant than S. aureus. in same concentration of green tea extracts at same pH. The resistance of S. aureus and Sal. typhimurium was increased with decreasing pH of culture broth. The morphology of S. aureus cells treated with green tea extracts showed damage of cell wall and cytoplasmic membrane. Severely damaged cells of S. aureus lost electron dense material and cytoplasm. Green tea extracts stimulated autolysis and cell death of S. aureus. This result suggests that green tea extracts can be used as an effective natural antibacterial agent in food.

• The Korean Journal of Mycology
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• v.40 no.1
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• pp.60-64
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• 2012

Physiological functionalities of culture concentrates from various fungi were investigated. The culture concentrates from Saccharomyces cerevisiae Y277-3 showed the highest tyrosinase inhibitory activity of 42.7%. Among mold physiological functionalities, the culture concentrates from Aspergillus orygae CN20-3-1-4 showed the highest antioxidant activity of 15.8%. The other functionalities of fungi were very low or not detected. The intracellular tyrosinase inhibitor from Saccharomyces cerevisiae Y277-3, which showed the highest physiological functionalities was maximally produced when the strain was cultured in PD broth at $30^{\circ}C$ for 24 h.

• KSBB Journal
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• v.28 no.6
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• pp.400-407
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• 2013

The growth characteristics and production of color pigments by Monascus strains were investigated during liquid culture, and production of monacolin K in red mold rice was carried out by solid state fermentation. Four different Monascus ruber strains were cultured in potato dextrose yeast extract broth (PDYB) media at $25^{\circ}C$ for 15 days. The high producing strain for red pigment was not corresponded to the strain for yellow pigment. Production of red pigment was high in the strain causing the fast pH change in culture broth. Production of monacolin K in red mold rice by solid state fermentation was influenced by a combination of wet cell weight and spore density in inoculum by liquid culture. Most strains showed the high production of monacolin K in red mold rice, when submerged fermentation was carried out for 5 days as inoculum for solid state fermentation. These results suggest that submerged fermentation period of inoculum have an effect on the production of monacolin K in red mold rice by solid state fermentation, and monacolin K in red mold rice could be increased by controlling the condition of submerged fermentation for inoculum.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.5-5
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• 1999

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.833-838
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• 2013

In this study, twelve strains of brewing fungi were individually cultivated on wheat extract broth (WEB), potato dextrose broth (PDB) and malt extract broth (MEB) in order to determine the microorganism with good culture characteristics as well as with amylolytic activity. The strain cultured in PDB exhibited mycelia production from 12.6 g/L (Rhizopus oryzae KACC 45714) to a maximum of 48.0 g/L (Aspergillus oryzae KACC 46959), which was 2.3~9.2 times lower than that of the strain cultured in WEB and 1.7~14.6 times lower than that of the strain cultured in MEB. Accorfing the results, We found that the commercial strains of A. oryzae Suwon, CF1001 and CF1003 had a higher dry cell mass than the wild-type strains KACC 46421, 46423, 46424 and 46959. For Rhizopus sp., the acidity levels in WEB, PDB and MEB were 0.12~0.47%, 0.22~1.0% and 0.16~0.68% (equivalent lactic acid concentration) respectively. For A. oryzae, the acidity levels were 0.06~0.11%, 0.03~0.04% and 0.06~0.08% (equivalent lactic acid concentration), respectively. Amylase enzyme from Rhizopus delemar KACC 46419 exhibited an enzyme activity of 0.013 U and 0.019 U in WEB and MEB cultures, respectively. The enzyme activity of the amylase enzyme from A. oryzae was 0.019~0.037, 0.017~0.033 and 0.028~0.046 U in WEB, PDB and MEB cultures, respectively.

• The Korean Journal of Food And Nutrition
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• v.22 no.4
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• pp.696-700
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• 2009

The adaptability of dry rehydratable film for the qualitative evaluation of coliform bacteria and Escherichia coli was tested. In general, culture methods that employ lactose broth or desoxycholate lactose agar are used for qualitative tests of coliform bacteria. Culture using lactose broth showed a high detection yield and low selectivity when compared to the dry rehydratable film. However, culture methods that employ lactose broth required a long time(48 hrs) for qualitative tests of coliform bacteria and complicated procedures were required to prepare the medium. The detection of coliforms using desoxycholate lactose agar had a slightly higher selectivity than the dry rehydratable film method, but this difference was not statistically significant. However, the preparation of the desoxycholate lactose agar was complicated. EC broth for the detection of E. coli showed the highest detection yield and lowest selectivity; however, this method required complicated procedures for preparation of the medium as well. Overall, the dry rehydratable film had a slightly lower detection yield than the other methods. The detection yield of dry rehydratable film method was over 37.1% at a concentration of 1 cfu/$m{\ell}$. Additionally, the dry rehydratable film method showed high selectivity and did not require preparation. However, because the selectivity of the dry rehydratable film was high, it took a long time(36 hrs) to detect E. coli. Overall, these findings indicate that dry rehydratable film can be used for qualitative detection of coliforms and E. coli.

• Korean Journal of Veterinary Research
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• v.9 no.1
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• pp.63-69
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• 1969

Various methods for the isolation of salmonellae were compared by examining mesenteric lymph nodes and faeces of 395 pigs at slaughter. The conclusions were as follows. (i) Tetrathionate broth was significantly superior to selenite broth for the examination of mesenteric lymph nodes. (ii) There was no significant difference between tetrathionate broth and selenite broth for the examination of faeces. The use of both tetrathionate broth and selenite broth as enrichment media for faeces produced far better results than the use of any single enrichment medium. (iii) Brilliant green agar was significantly superior to SS agar for the examination of mesenteric lymph nodes. (iv) There was no significant difference between brilliant green agar and SS agar when faeces were examined. The use of both media produced far better results than the use of either singly. (v) Brilliant green MacConkey broth was much inferior to tetrathionate broth as an enrichment broth. Direct culture of faeces on brilliant green MacConkey agar yielded less isolates than prior enrichment in tetrathionate or selenite broth. (vi) The optimum incubation period of enrichment was 24 hours for faeces and 48 hours for mesenteric lymph nodes when either tetrathionate broth or selenite broth was used as enrichment media.