• The Korean Journal of Ecology
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• v.21 no.3
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• pp.277-282
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• 1998

The microbial degradation of $poly-{\beta}-hydroxybutyrate$ (PHB) films was studied in soil microco는 incubated at a constant temperature of 2, 10, 20, 30 and $40^{\circ}C$ for up to 49 days. The degradation rate measured through loss of weight was enhanced by incubation at a higher temperature. At the soil temperature $40^{\circ}C$, $poly-{\beta}-hydroxybutyrate$ was rapidly degraded at a decay rate of 3.5% weight loss per day. The degradation of $poly-{\beta}-hydroxybutyrate$ did not affected significantly the chemical properties of soils such as pH and electric conductivity. However, microbial activity of soil in terms of dehydrogenase activity was increased by the degradation of $poly-{\beta}-hydroxybutyrate$.

• Journal of Aquaculture
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• v.14 no.1
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• pp.17-27
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• 2001

Effects of temperature (10, 12, 14, 16, 18 and 2$0^{\circ}C$) and salinity (22.0, 24.5, 27.0, 29.5, 32.0 and 34.5 ppt) were studied on incubation period, hatching success, survival and growth of alevin and juvenile seabass, L. japonicus. Embryonic development was accelerated with increasing temperature but it was not influenced by salinity. Hatching success was the highest at 14$^{\circ}C$ and 34.5 ppt. Higher temperature also accelerated the development of mouth opening, absorption of yolk and oil globules, and alevin growth. Survival of the 5-day old Juvenile was accelerated in the following order : 14<16<18<20<12$^{\circ}C$. Rearing experiment of the juvenile for 30-day indicated the faster growth at 13, 20 and 27 ppt than at 34 ppt.

• Korean Journal of Microbiology
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• v.3 no.1
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• pp.7-10
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• 1965

Higher number in colony counts in coliforms, total aerobes, and anerobes was obtained from marketable soy-bean mash than front that in fermented tank. The ratio between coliform contamination and total viable cells was higher in red pepper mash than in soy-bean mash. E. coli, contaminated in soy-bean mash persisted longer at low temperature ($0^{\circ}C$-$^5{\circ}C$) than at room temperature and they vanished after seven days of storage at room temperature. At 30.deg.C and 35.deg.C, these organisms were more effected than at room temperature. E. coli cells, inoculated in red pepper mash, were not recovered at room temperature after five days incubation. Soy-bean mash, completely fermented at normal conditions, were detected to contain $10^8$- $10^9$ organisms per gram of sample. On the contrary, marketable soy-bean mash were found to have more than 10$^{9}$ per gram samples. Since samples were found to have more than $10^9$ aerobes and anaerobes per gram, contamination of coliforms seemed to be apparent.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.558-563
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• 2001

A new alkalophilic strain of Bacillus pumilus JB¬05 producing bleach-stable and halo-tolerant alkaline protease was isolated from cement industry effluents in Karnataka, India. The effects of carbon and nitrogen sources on protease production by this alkalophilic strain were observed after a 30-h incubation. A high level of alkaline protease activity was obtained in the presence of starch as the carbon and peptone as the nitrogen sources. The partially purified enzyme showed an optimum temperature and pH activity at $58^{\circ}C$ and 10.5, respectively. The enzyme was completely inhibited by PMSF (95.0%) indicating it as a serine protease. It is bleach-stable as it retained 35% original activity in the presence of 10% (v/v) hydrogen peroxide at $30^{\circ}$C after 2 h and is halo-tolerant as it retained 70% original activity in the presence of 2.5 M sodium chloride at $30^{\circ}C$ after 2 h incubation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.509-514
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• 1994

Penicillium purpurogenum , which produces a copra galactomannan degrading enzyme extracellularyl, was isolated from soil , and its properties and formation condition of mannooligosaccharides were investigated. The optimum ph and temperature for the activity of the mannanase were 5.5 and 55$^{\circ}C$, respectively. The mannanase was stable in between pH 3.5 and 7.0 after 2 hr incubation at 3$0^{\circ}C$ lost 90% of the original activity after incubation at 55$\AA$ and pH 5.5 for 2 hr. With two different substrate concentration, hydrolysis of white coprameal proceeded rapidly at the early stage of the reaction, but gradually solwed thereafter especially at a higher concentration of copra meal (20 %). The enzyme hydrolyzed white copra meal to monosaccharides, mannobiose and mannotriose at the final stage of the reaction.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.17-23
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• 1995

We studied the influence of culture conditions on the acid tolerance of Lactobacillus casei YIT 9018 in artificial gastric juice with respect to relative amount of membrane bound ATPase and their biochemical characteristics. With raising incubation temperature from 30.5$\circ$C to 40.5$\circ$C and lengthening incubation time from exponential phase to late stationary phase, the acid tolerance of L. casei YIT 9018 was increased. As acid tolerance enhanced, C$_{18:1}$ content of membrane fatty acid was reduced and C$_{19:0 cyclo}$ was enriched but the others were not changed greatly. At high ATPase activity, proton permeability was relatively low but this phenomenon did not correspond to acid tolerance. In conclusion, it was considered that changes of C$_{18:1}$ and C$_{19:0 cyclo}$ were closely related to the acid tolerance of L. casei YIT 9018.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.364-367
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• 2005

This study investigated the production of antioxidant from Actinomyces culture supernatant. For the research of the natural marine antioxidant, several bacteria were isolated from the coast of Je-ju in Korea. An actinomycetes strains, S-1 was identified to a genus level 16S ribosomal DNA sequence and fatty acid analysis. From these results and other characteristics described in the Bergey's Manual, this strain was identificated as a Nocardiopsis dassonvillei. Strain S-1 showed high activity of 1,1-diphenyl-2-prcrylhydrazyl radical scavenging. The hydroxyl radical scavenging ability of Nocardiopsis sp. S-1 supernatant was 53%. Nutritional and cultural conditions for the production of antioxidant by this organism under shake-flask conditions have optimized. Similary initial medium pH 7.6, incubation temperature of $25^{\cicr}C$, sodium chloride concentration 2.5 and incubation time of 8 day were found to be optimal.

• Journal of Sericultural and Entomological Science
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• v.10
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• pp.59-62
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• 1969

It is very important physiological and economical problems to hatching within a day by increasing hatching-ratio of silkworm eggs in sericulture, and modified dark incubating method was experimented in Japan. The author studied on the economical problems of that rather than physiological study. Hatching was induced and accelerated by illumination before hatching 5 days which incubated in the dark room after eye spot pigmented eggs emerged 10-20 percentage. It was increased by 80-90％ in hatching-ratio, but the hatching was delayed a day. In autumn silkworm, newly hatched silkworms were hatched silkworms were hatched in the dark room because of high temperature period tough modified dark incubation was passed only 4 days. The author wonder which is more effective between effect of increasing the hatching-ratio and the health of silkworms.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.1
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• pp.37-40
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• 2003

The antibacterial action of violet pigment, a mixture of violacein and deoxyviolacein, isolated from phychrotrophic bacterium RT102 strain was examined, and the operational conditions for the effective production of violet pigment were studied. The antibacterial activity of the violet pigment was confirmed for several bacteria such as Bacillus licheniformis, Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, and Pseudomonas aeruginosa, and the high concentration of violet pigment, above about 15mg/L, caused not only growth inhibition but also death of cells. The growth properties of RT102 strain were clarified under various incubation conditions such as pH, temperature, and dissolved oxygen concentration. The maximum violet pigment concentration, i.e. 3.7 g/L, and the maximum productivity of violet pigment, i.e. 0.12 g .L$\^$-1/H$\^$-1/, were obtained in a batch culture of pH 6, 20$^{\circ}C$, and 1 mg/L of dissolved oxygen concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.513-518
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• 1996

In order to investigate the characteristics of alcohol fermentation by Saccharomyces cerevisiae, compositions and free sugar content of dried riped pumpkin powder were determined. The proximate compositions of ripe pumpkin powder were as follows: moisture 11.98%, total sugar 62.18%(dried weight basis 70.64%), protein 13.38%, lipid 0.85%, fiber 7.07% and ash 4.54%. The compositions of free sugar in well ripe pumpkin were: glucese 85.36mg/g, fructose 40.68mg/g, sucrose 68.25mg/g, lactose 18.60mg/g and maltose 3.82mg/g. The optimum conditions for alcohol fermentation by S. cerevisiae were as follows; incubation temperature of 3$0^{\circ}C$, initial pH of 6.0, ripe pumpkin powder concentration of 10% and cells inoculation of 1.3$\times$$10^{6}$ cells/ml liquid medium. Ethanol production under the optimum conditions was 5.95g/100g in liquid medium containing 10% ripe pumpkin powder after 4 days incubation.