• Microbiology and Biotechnology Letters
• /
• v.29 no.3
• /
• pp.134-141
• /
• 2001

A bacterial strain KP-364 producing extracellular keratinolytic protease was isolated from the soil of the poultry fac-tory. It was identified as Pseudomonas sp. based on its morphological and physiological characteristics, The optimal culture conditions for the production of keratinolytic protease by Pseudomonas sp. KP-364 were investigated. The composition of optimal medium for the keratinolytic protease was 2.0% glucose, 0.5% soybean meal. 0.5% $NaNO_3$ and 0.2% KCI Optimal initial pH for production of Keratinolytic protease production were 6.5 and $37^{\circ}C$ respec- tively. The keratinolytic protease production reached a maximum of 1,270 U/ml/hr after 48 hours cultivation under the optimal culture conditions.

• Microbiology and Biotechnology Letters
• /
• v.19 no.2
• /
• pp.135-139
• /
• 1991

Tridecanedioic acid (DC-13), starting material of the valuable musk ethylene brassylate, was obtained from n-tridecane by the Candida tropicalis mutant. The mutants were first obtained from primary screening step using the selective medium and then solid phase extraction sampling method was used for the selective isolation of organic acids from the cultured media of mutants. The resulting acids were directly converted to volatile tert-butyldimethyl silyl delivatives, which were then analyzed by gas chromatography. The efficient GC profiling method was used for the rapid identification of the mutant producing DC-13 in large quantity, and for the optimization of the culture conditions of mutant. The optimal culture conditions were found as follows: pH 8.0, 30$^{\circ}C$, 250rpm, 48hour of culture and $(NH_4)_2HPO_4$ as nitrogen source.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.7
• /
• pp.1206-1215
• /
• 2016

Ginsenosides are the major active ingredients in ginseng used for human therapeutic plant medicines. One of the most well-known probiotic bacteria among the various strains on the functional food market is Lactobacillus rhamnosus GG. Biocatalytic methods using probiotic enzymes for producing deglycosylated ginsenosides such as Rd have a growing significance in the functional food industry. The addition of 2% cellobiose (w/v) to glucose-free de Man-Rogosa-Sharpe broths notably induced β-glucosidase production from L. rhamnosus GG. Enzyme production and activity were optimized at a pH, temperature, and cellobiose concentration of 6.0, 40℃, and 2% (w/v), respectively. Under these controlled conditions, β-glucosidase production in L. rhamnosus GG was enhanced by 25-fold. Additionally, whole-cell homogenates showed the highest β-glucosidase activity when compared with disrupted cell suspensions; the cell disruption step significantly decreased the β-glucosidase activity. Based on the optimized enzyme conditions, whole-cell L. rhamnosus GG was successfully used to convert ginsenoside Rb1 into Rd.

• KSBB Journal
• /
• v.25 no.6
• /
• pp.513-519
• /
• 2010

Marine bacterium producing pigment was isolated from the solar saltern of Mijo-myeon, Namhae, Korea. Based on phenotypic characteristics and 16S rRNA sequence analysis, the strain was identified as Kocuria sp., which produced a yellow pigment. The pigment showed UV absorption maximum at 469nm. The bacterial strain grew well on Marine broth 2216 culture medium. Productivity of the pigment reached the maximum value after 44 hours at $30^{\circ}C$, 2% NaCl and pH 6.0. The pigment was produced best when supplied by 1% lactose as a carbon source and 1% beef extract as a nitrogen source. The result of the color stability study showed that pigment extracted from the strain by ethanol was stable at $-20-25^{\circ}C$ and also showed higher stability over 70% for 14 days in light conditions at $25^{\circ}C$. The pigment extract was also stable for all metal ions tested, except for $FeCl_2$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.4
• /
• pp.418-422
• /
• 1992

Mucor mucedo C-7 selected as a potent fungus for producing milk-clotting enzyme was cultured on wheat bran solid medium and the optimum culture conditions for the production of milk clotting enzyme were ot tamed as follows. Amount of water added to wheat bran was 100% to the weight of wheat bran and culture temperature and time was 3$0^{\circ}C$ and 72hrs, respectively. The production of milk-clotting enzyme was markedly increased by the addition of Macllvaine buffer solution (pH4.5) instead of water added to wheat bran solid medium and milk-clotting activity was stable for culture period.

• Food Science and Preservation
• /
• v.10 no.4
• /
• pp.554-559
• /
• 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 the East Asian Society of Dietary Life
• /
• v.20 no.5
• /
• pp.743-750
• /
• 2010

The influence of various fermenting conditions using Saccharomyces cerevisiae, alone (Control, Single) and in combination with mixed lactic acid-producing bacteria (Combined 1, Mixed, Combined 2), including Bifidobacterium longum, Enterococcus faecium, and Lactobacillus acidophilus on flour sourdough preparation was examined. For the Combined 2 method, starters were incubated separately for 15 h, combined, and then further incubated for 10 h. Fermentation using Combined 2 improved the growth of mixed lactic acid-producing bacteria, but inhibited that of S. cerevisiae. This was also reflected in the extent of the pH reduction in sourdough produced in the Combined 2 step by these organisms. Among biochemical activities, $CO_2$ production and titratable acidity were increased by Combined 2, although the viable yeast counts were decreased. Aroma compounds in sourdough markedly varied according to fermentation conditions.

• Microbiology and Biotechnology Letters
• /
• v.29 no.2
• /
• pp.110-114
• /
• 2001

Isolation of BacilLus sp. producing multi-enzyme and optimization of medium conditions for its production using feedstuffs for probiotics were carried out in this study. A bacterium isolated from natural resources, namely Bacillus subtilis 4-3, has multi-enzyme activity (phytase. cellulase, xylanasc, protease, and amylase. In the culture of B. subtilis 4-3 using soybean meal and rice bran. relatively low phytate degradation was noted using whereas high phytate degradability was observed with wheat bran (80.63%). The optimal composition of medium using feedstuffs was 1.0% (w/v) soybean meal and 2% (w/v) molasses to yield high cell growth.

• Food Science of Animal Resources
• /
• v.38 no.6
• /
• pp.1315-1321
• /
• 2018

Bacteriocin is ribosomally synthesized by bacteria and inhibits closely related species. In this study we aimed at isolating lactic acid bacteria producing bacteriocin presenting anti-staphylococcal activity. A Lactococcus lactis strain was isolated from kimchi for the purpose and identified by 16S rRNA gene sequencing. As preliminary tests, optimal culture conditions, stabilities against heat, solvents, and enzymes treatments, and type of action (bacteriostatic or bactericidal) of the bacteriocin were investigated. The optimal culture conditions for production of the bacteriocin were MRS broth medium and $25^{\circ}C$ and $30^{\circ}C$ culture temperatures. The bacteriocin was acidic and the activity was abolished by a protease treatment. Its stability was maintained at $100^{\circ}C$ for 15 min and under treatments of various organic solvents such as methanol, ethanol, acetone, acetonitrile, and chloroform. Finally, the bacteriocin showed bactericidal action against Staphylococcus aureus where 200 AU/mL of the bacteriocin decreased the viable cell count (CFU/mL) of S. aureus by 2.5 log scale, compared with a control (no bacteriocin added) after 4-h incubation.

• The Journal of Fisheries Business Administration
• /
• v.32 no.1
• /
• pp.1-14
• /
• 2001

The research on the price-volume relation in the market is very important because it examines into regular phenomenon revealed by market participants including producers and middlemen. The purpose of this study is to investigate the relationship between price and trading volume in the oyster producing market. In order to accomplish the purpose of this study, the contents of empirical analysis include the time series properties of price and trading volume, the short-term and long-term relationships between price and trading volume, and the determinants of trading volume. The data used in this study correspond to daily price and trading volume covering the time period from January 1998 to April 2001. The empirical results can be summarized as follows : First, price and trading volume follow random walks and they are integrated of order 1. The first difference is necessary for satisfying the stationary conditions. Second, price and trading volume are cointegrated. This long-run relationship is stronger from trading volume to price. Third, error correction model suggests that feedback effect exists in the long-run and that price tends to lead trading volume by about five days in the short run, that is, to be required period by digging, conveying, and peeling oystershell for selling oyster. Fourth, price and price volatility is a determinant of trading volume. In particular, trading volume is a negative function of price. It is believed that the conclusion drawn from this study would provide a useful standard for the policy makers in charge of reducing the oyster price volatility risk caused by trading volume(selling quantities).