• Journal of Microbiology and Biotechnology
• /
• 제9권2호
• /
• pp.223-226
• /
• 1999

A bacterial strain producing high level of an extracellular phytase was isolated from cooked rice and identified as a strain of Bacillus sp. and designated as Bacillus sp. KHU-10. Optimum culture conditions were investigated for the maximum productivity of phytase by Bacillus sp. KHU-10. 1.0% Maltose and 1.0% peptone with 0.5% beef extract were the best carbon source and nitrogen source, respectively. The addition of $CaCl_2$, stimulated the enzyme productivity with concentration between 0.01% and 0.2%, in the medium. Although sodium phosphate increased the cell mass, the enzyme activity decreased. Calcium phytate and wheat bran containing phytate did not enhance the enzyme production. Under the optimum medium, the production of the phytase reached the highest level of 0.2 unit/ml after 4 days of incubation.

• Journal of Microbiology and Biotechnology
• /
• 제19권9호
• /
• pp.982-986
• /
• 2009

For the production of ghost bacteria vaccine to prevent the streptococcal disease in aquaculture fish species, a double cassettes vector was constructed and cloned in Escherichia coli DH5${\alpha}$. Ghost bacteria vaccine production from Escherichia coli DH5${\alpha}$/pHCE-InaN-GAPDH-Ghost 37 SDM (SIG) was maximized at a glucose concentration of 1 g/l, agitation of 300 rpm, and aeration of 1 vvm. The maximal efficiency of ghost bacteria formation was obtained at the mid-exponential phase ($OD_{600}=2.0$) with the concentration of 0.77 g/l for SIG. The molecular mass of GAPDH was detected at 67 kDa with the insoluble fraction, by SDS-PAGE and Western blot. The protective efficacy of ghost bacteria vaccine was evaluated by challenge test using olive flounder. The cumulative mortalities of the positive control, formalin-killed cell (FKC) vaccine, and SIG vaccine immunized groups were 91%, 74%, and 57%, respectively. These results suggest that SIG vaccine showed efficacy as a vaccine and had a higher potential to induce protective antibodies than did FKC vaccine.

• Mycobiology
• /
• 제38권4호
• /
• pp.286-294
• /
• 2010

Epicoccum purpurascens stain 5615 AUMC was investigated for its biocontrol activity against root rot disease caused by Pythium irregulare. E. purpurascens greenhouse pathogenicity tests using three leguminous plants indicated that the fungus was nonpathogenic under the test conditions. The germination rate of the three species of legume seeds treated with a E. purpurascens homogenate increased significantly compared with the seeds infested with P. irregulare. No root rot symptoms were observed on seeds treated with E. purpurascens, and seedlings appeared more vigorous when compared with the non-treated control. A significant increase in seedling growth parameters (seedling length and fresh and dry weights) was observed in seedlings treated with E. purpurascens compared to pathogen-treated seedlings. Pre-treating the seeds with the bioagent fungus was more efficient for protecting seeds against the root rot disease caused by P. irregulare than waiting for disease dispersal before intervention. To determine whether E. purpurascens produced known anti-fungal compounds, an acetone extract of the fungus was analyzed by gas chromatography mass spectrometry. The extract revealed a high percentage of the cinnamic acid derivative (trimethylsiloxy) cinnamic acid methyl ester. The E. purpurascens isolate grew more rapidly than the P. irregulare pathogen in a dual culture on potato dextrose agar nutrient medium, although the two fungi grew similarly when cultured separately. This result may indicate antagonism via antibiosis or competition.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제33권1호
• /
• pp.24-30
• /
• 2016

1-Deoxynojirimycin (DNJ) have been extensively investigated for their α-glucosidase inhibitor on postprandial hyperglycemia, and applied in nutraceuticals and medicine for preventing or delaying progression of type 2 diabetes. However, the amount of DNJ in mulberry leaves is low (about 0.1%), therefore, more effective extraction method is needed. This study was performed to develop microbial DNJ for biological methods of DNJ as an alternative to the chemical methods. In this study, we obtained evidence for Bacillus subtilis that produce DNJ in large quantities by high performance liquid chromatography. Inhibition of α-glucosidase activity was determined to DNJ production or non-production. Investigation of the effect of mulberry leaves powder concentration (1~5%), using the DNJ high-production bacteria, provided evidence for microbial mass production of DNJ. When the 4% mulberry leaf powder for 9 days was used, the α-glucosidase inhibitory activity was over the 85%. Also, the results presented in this study confirm DNJ yield's increasement in microbes using the various of nutrients and provide insight of ways to improve DNJ yields in microorganisms.

• 수산해양교육연구
• /
• 제25권5호
• /
• pp.1205-1213
• /
• 2013

We investigated the optimum salinity and temperature conditions for the mass culture of small rotifer, Keratella sp.. In the salinity experiment ranging from 0-34‰, the population growth of Keratella sp. drastically increased continuously up to 15‰, and then slightly increased over 20‰. Their maximum density reached 1,007 inds./mL at 0‰. A pre-reproductive phase was shorter in low salinity than in high salinity. The highest number of offspring per female (10.2 inds.) and lifespan of the female (10.7 days) were obtained at 0‰, but there were no significant differences compared to those at 5‰. In the temperature experiments ranging from 16-$32^{\circ}C$, the highest maximum density (1,766 inds./mL) was shown at $24^{\circ}C$. The number of offspring per female significantly increased with increasing temperature, and the highest number of offspring per female was 10.4 inds. at $24^{\circ}C$. The lifespan of female increased with decreasing temperature and the longest lifespan was 12.8 days at $16^{\circ}C$.

• Journal of Microbiology and Biotechnology
• /
• 제9권5호
• /
• pp.593-603
• /
• 1999

Poly(3-hydroxybutyrate) (PHB) production by fermentation was examined under both restricted- and ample-oxygen supply conditions in a single fed-batch fermentation. Recombinant Escherichia coli transformed with the PHB production plasmid pSYLl07 was grown to reach high cell density (227 g/l dry cell weight) with a high PHB content (78％ of dry cell weight), using a glucose-based minimal medium. A simple flux model containing 12 fluxes was developed and applied to the fermentation data. A superior closure (95％) of the carbon mass balance was achieved. When the data were put into use, the results demonstrated a surprisingly large excretion of formate and lactate. Even though periods of severe oxygen limitation coincided with rapid acetate and lactate excretion, PHB productivity and carbon utilization efficiency were not significantly impaired. These results are very positive in reducing oxygen demand in an industrial PHA fermentation without sacrificing its PHA productivity, thereby reducing overall production costs.

• 한국안광학회지
• /
• 제10권1호
• /
• pp.17-25
• /
• 2005

고도의 산업화와 매스미디어의 발달로 인해 개성화, 다양화를 강조하는 현대사회에서는 시각적인 요소를 매우 중요시 여기게 되었으며, 이를 계기로 Total Fashion의 시대가 막을 열었다. 과거의 안경디자인 트랜드는 시력교정과 시력보호라는 고전적인 목적을 가지고 단순한 형태와 기능 등 획일적인 양상을 띠었으나, 21C 안경디자인은 시력교정과 시력보호라는 과거의 기능 이외에 문화와 패션 트랜드에 발맞추어 급변해 가고 있다. 따라서 본 연구는 안경의 시대적 변천과정을 살펴보고 의상, 헤어와 메이크업 동향에 따른 안경디자인의 추세와 색상이미지를 분석하여 21C 안경디자인의 조건을 고찰하였다.

• Journal of Applied Biological Chemistry
• /
• 제59권4호
• /
• pp.289-298
• /
• 2016

FK506 hyper-yielding mutant, called the TCM8594 strain, was made from Streptomyces tsukubaensis NRRL 18488 by mutagenesis using N-methyl-N'-nitro-N-nitrosoguanidine, ultraviolet irradiation, and FK506 sequential resistance selection. FK506 production by the TCM8594 strain improved 45.1-fold ($505.4{\mu}g/mL$) compared to that of S. tsukubaensis NRRL 18488 ($11.2{\mu}g/mL$). Among the five substrates, wheat bran was selected as the best solid substrate to produce optimum quantities of FK506 ($382.7{\mu}g/g$ substrate) under solid-state fermentation, and the process parameters affecting FK506 production were optimized. Maximum FK506 yield ($897.4{\mu}g/g$ substrate) was achieved by optimizing process parameters, such as wheat bran with 5 % (w/w) dextrin and yeast extract as additional nutrients, 70 % (v/w) initial solid substrate moisture content, initial medium pH of 7.2, $30^{\circ}C$ incubation temperature, inoculum level that was 10 % (v/w) of the cell mass equivalent, and a 10 day incubation. The results showed an overall 234 % increase in FK506 production after optimizing the process parameters.

• Journal of Microbiology and Biotechnology
• /
• 제20권12호
• /
• pp.1664-1671
• /
• 2010

A new biosurfactant producer was isolated from palm-oil-contaminated soil and later identified through morphology and DNA sequencing as the yeast-like fungus Exophiala dermatitidis. Biosurfactant production was catalyzed by vegetable oil, supplemented with a basal medium. The culture conditions that provided the biosurfactant with the highest surface activity were found to be 5% palm oil with 0.08% $NH_4NO_3$, at a pH of 5.3, with shaking at 200 rpm, and a temperature of $30^{\circ}C$ for a 14-day period of incubation. The biosurfactant was purified, in accordance with surfactant properties, by solvent fractionation using silica gel column chromatography. The chemical structure of the strongest surface-active compound was elucidated through the use of NMR and mass spectroscopy, and noted to be monoolein, which then went on to demonstrate antiproliferative activity against cervical cancer (HeLa) and leukemia (U937) cell lines in a dose-dependent manner. Interestingly, no cytotoxicity was observed with normal cells even when high concentrations were used. Cell and DNA morphological changes, in both cancer cell lines, were observed to be cell shrinkage, membrane blebbling, and DNA fragmentation.

• KSBB Journal
• /
• 제5권2호
• /
• pp.101-106
• /
• 1990

Aureobasidium pullulans에 의한 플루란 생산이 다양한 pH,탄소원, 질소원 조건하에서 수행되었다. 발효 배양액과 배출기체 조성은 GC,LC,GPC를 이용하여 분석되었다. 초기 pH 6.0이고 sucrose 50g/l를 사용했을 때 27g/l 의 플루란이 생산되었다. pH가 3이하로 내려가면 균체량은 증가하지만 플루란 생산은 거의 정지되었다. 질소원으로$(NH_4)_2SO_4$만 사용한 경우의 발효에서는 pH가 3이하로 감소하였기 때문에 플루란 생산량이 감소하였기 때문에 플루란 생산량이 적었으며 탄소원으로 포도당을 사용했을 때도 비슷한 현상이 관찰되었다. sucrose같은 2당류를 기질로 사용했을 때 2당은 포도당과 3당류로 분해되고 포도당은 세포내에서 플루란으로 중합된 후 세포 밖으로 배출되는 것으로 추론되었다.