• 한국미생물·생명공학회지
• /
• 제22권5호
• /
• pp.561-563
• /
• 1994

For the more effective isolation of soil actinomycetes, we have developed HHV (Hair hydrolysate-vitamin) agar medium, containing hair as the sole source of carbon and nitrogen. The HHV agar medium was superior to other media such as colloidal chintin agar, glycerol-arginine agar and starch-casein-nitrate agar, and HV (humic acid-vitamin) agar. The maximum effect of this medium has been shown in hair dry weight 0.4 g/l medium. Of each soil sample, the greatestest number of actinomycetes was isolated from the potato annual planted soil among the tested samp- les. The genus of actinomycetes isolated from the potato annual planted soil sample was identified such 5 group as Stretomyces, Micromonospora, Microbispora, Nocardia and Saccharopolyspora.

• 생약학회지
• /
• 제31권3호
• /
• pp.268-272
• /
• 2000

GE974, isolated from Gyrophora esculenta, showed significant inhibitory effect on several ${\alpha}-glucosidases$ in vitro in previous study. In the present study, GE974 showed significant inhibitory effect on blood glucose elevation in mice loaded with maltose, sucrose, starch and lactose. Also, it exhibited similar effect in alloxan and streptozotocin induced diabetic mice, and genetic diabetic mice(db/db mice) loaded with maltose in dose dependent manner. These results suggest that GE974 may possess hypoglycemic effect that inhibit competitively ${\alpha}-glucosidase$ activities.

• Applied Biological Chemistry
• /
• 제29권1호
• /
• pp.29-35
• /
• 1986

수분흡수속도가 다른 쌀로부터 추출한 전분의 알카리 호화양상을 조사하였다. 일정할 알카리 농도에서 최고점도와 점도의 증가속도 및 알카리 농도를 증가시킬 때의 점도의 증가 속도는 다수계 쌀 전분이 일반계 쌀 전분보다 높았다. 쌀전분의 점도양상은 쌀가루의 점도양상 및 쌀의 수화속도와는 상관관계를 보이지 않았다.

• Mycobiology
• /
• 제48권3호
• /
• pp.195-203
• /
• 2020

Marine yeasts have tremendous potential in industrial applications but have received less attention than terrestrial yeasts and marine filamentous fungi. In this study, we have screened marine yeasts for amylolytic activity and identified an amylase-producing strain PH-Gra1 isolated from sea algae. PH-Gra1 formed as a coral-red colony on yeast-peptone-dextrose (YPD) agar; the maximum radial growth was observed at 22 ℃, pH 6.5 without addition of NaCl to the media. Based on the morphology and phylogenetic analyses derived from sequences of internal transcribed spacer (ITS) and a D1/D2 domain of large subunit of ribosomal DNA, PH-Gra1 was designated Sporidiobolus pararoseus. S. pararoseus is frequently isolated from marine environments and known to produce lipids, carotenoids, and several enzymes. However, its amylolytic activity, particularly the optimum conditions for enzyme activity and stability, has not been previously characterized in detail. The extracellular crude enzyme of PH-Gra1 displayed its maximum amylolytic activity at 55 ℃, pH 6.5, and 0%-3.0% (w/v) NaCl under the tested conditions, and the activity increased with time over the 180-min incubation period. In addition, the crude enzyme hydrolyzed potato starch more actively than corn and wheat starch, and was stable at temperatures ranging from 15 ℃ to 45 ℃ for 2 h. This report provides a basis for additional studies of marine yeasts that will facilitate industrial applications.

• 한국미생물·생명공학회지
• /
• 제14권6호
• /
• pp.461-466
• /
• 1986

본 연구에서는 CGTase 생산성이 높은 균주인 Bacillus sp.를 자연계에서 분리하였고 이 균주의 특성, 분비효소의 특성, 효의 생산조건 및 효소이용 가능성에 대한 기초연구를 실시하였다. 분리균주는 운동성이 있는 내성포자형성 간균이었고 분비효소의 최적작용조건은 pH 6.0, 45$^{\circ}C$이며 pH 6-10 범위에서 안정하였다. 효소생산조건은 탄소원으로 corn starch 1%, 질소원으로서 corn steep liquor 5%, urea 0.1%, ammonium sulfate 0.25%를 동시에 첨가하는 것이 가장 양호하였으며 본 생산균을 30$\ell$ jar fermentor로 3$0^{\circ}C$, 200rpm, 0.6vvm에서 60시간 정도 배양하였을 때 최대의 효소 생산력을 나타내었다. 또한 본 효소를 이용하여 stevioside를 acceptor로 하고 전분가수분해물을 donor로 하여 당전이반응을 실시한 결과 상당한 전이효과가 나타났으므로 기타 전이제품 및 cyclodextrin 생산에 응용이 가능할 것으로 기대된다.

• 생명과학회지
• /
• 제14권5호
• /
• pp.815-820
• /
• 2004

본 연구에서 미생물유래의 종양 예방 및 억제제 개발을 목적으로 우리나라 전통 발효식품인 젓갈에서 항암 활성이 우수한 미생물을 분리, 동정 하였다. 젓갈로부터 항암물질을 생산하는 균주 SW-1을 분리하여 형태학적, 생리학적 특성을 검토한 결과, 본 균주는 Bacillus subtillis SW-1으로 동정되었다. 본 균주로부터 항암물질은 실험에 사용한 두가지의 암세포에 강한 활성을 나타내었다. 그 중에서 폐암 세포인 A549에 가장 강한 활성을 나타내었다. 항암물질 생산을 위한 최적 배양조건을 검토한 결과, 3.0% soluble starch, 1.0% yeast extract 였다. 무기염의 경우는 활성에는 그다지 영향을 미치지 않았다. 배지의 초기 pH 및 배양온도에 따른 항암물질의 생산성을 검토한 결과 초기 pH 5.0배양온도 3$0^{\circ}C$에서 25시 간배양 했을 때 최대 활성을 보였다. Chromosomal DNA단편화 실험에서 Bacillus subtilis SW-1의 배양상등액을 처리했을 때 DNA가 사닥다리모양으로 분해되는 Apoptosis(계획된 세포죽임)를 일으키는 것으로 확인되었다. 이 미생물이 생성하는 물질을 현재 HPLC, GC등을 이용하여 분리 중에 있으며 현재까지의 결과로는 당 중합체 인 것으로 분석된다.

• Applied Biological Chemistry
• /
• 제40권6호
• /
• pp.459-464
• /
• 1997

Cyclodextrin glycosyltransferase 생산균주를 토양으로부터 분리하여 형태학적, 생화학적 그리고 균주의 세포벽 지방산 조성분석에 의해 Bacillus brevis로 동정하였고, Bacillus brevis CD162로 명명하였다. 또한 배지조성에 따른 cyclodextrin glycosyltransferase의 최적생산조건을 검토한 결과, 2.0% soluble starch, 0.75% yeast extract, 0.5% bacto peptone, 0.2% $K_2HPO_4$, 0.05% $MgSO_4{\cdot}7H_2O$, 1.5% $Na_2CO_3$ (pH 10.2)의 배지 조건에서 $30^{\circ}C$에서 96시간 배양하였을 때 가장 높은 효소생산인 0.9 unit/ml을 얻을 수 있었다.

• Applied Biological Chemistry
• /
• 제41권5호
• /
• pp.342-348
• /
• 1998

대두단백질 가수분해물의 이용과 특성 등을 향상시키기 위한 연구의 일환으로, 쓴맛성분이 적고 향미가 우수한 가수분해물의 제조에 이용되는 protease를 생산하기 위하여, 전국 각지역의 메주에서 대두 단백 분해 효소의 생산이 우수한 균을 분리하였고, 형태학적, 생화학적 특징을 검토한 결과, Bacillus subtilis로 동정 되었고, Bacillus subtilis YG-95로 명명하였다. 단백분해효소 생산을 위한 배지의 최적 조건을 검토한 결과 soluble starch 3.5%, soy protein isolate 3.0%, dextrose 0.25%, NaCl 0.5%, dipotassium phosphate 0.25%의 배지의 조건에서 배양 최적 pH는 7.6, 최적 배양온도는 $45^{\circ}C$, 최적 배양시간은 60시간으로 배양했을 때 효소의 생산에 최적조건이었다.

• Journal of Microbiology and Biotechnology
• /
• 제21권9호
• /
• pp.947-953
• /
• 2011

A fungal strain, Aspergillus terreus strain GA2, isolated from an agricultural field cultivating sweet sorghum, produced feruloyl esterase using maize bran. In order to obtain maximum yields of feruloyl esterase, the solid state fermentation (SSF) conditions for enzyme production were standardized. Effective feruloyl esterase production was observed with maize bran as substrate followed by wheat bran, coconut husk, and rice husk among the tested agro-waste crop residues. Optimum particle size of 0.71-0.3 mm and moisture content of 80% favored enzyme production. Moreover, optimum feruloyl esterase production was observed at pH 6.0 and a temperature of $30^{\circ}C$. Supplementation of potato starch (0.6%) as the carbon source and casein (1%) as the nitrogen source favored enzyme production. Furthermore, the culture produced the enzyme after 7 days of incubation when the C:N ratio was 5. Optimization of the SSF conditions revealed that maximum enzyme activity (1,162 U/gds) was observed after 7 days in a production medium of 80% moisture content and pH 6.0 containing 16 g maize bran [25% (w/v)] of particle size of 0.71-0.3 mm, 0.6% potato starch, 3.0% casein, and 64 ml of formulated basal salt solution. Overall, the enzyme production was enhanced by 3.2-fold as compared with un-optimized conditions.

• Food Science and Biotechnology
• /
• 제14권4호
• /
• pp.461-465
• /
• 2005

To determine the cause of wet noodle spoilage, microorganisms isolated from wet noodles were identified and characterized. In addition, the growth inhibitory effects of organic acid mixture (OA: lactic acid 27.8%, acetic acid 12.0%, succinic acid 1.0%) and sodium dehydroacetate (SD) on the isolated strain were estimated in nutrient broth medium. The isolated strain was Gram-positive, rod shaped, motile, and spore forming. Based on physiological characteristics and the API 50 CHB-kit test results for the assimilation of 49 carbohydrates, the isolated strain was identified as Bacillus amyloliquefaciens (92.6%), which is able to degrade starch. Decimal reduction times (D-values) at 100, 105, and $110^{\circ}C$ for spores of B. amyloliquefaciens were 8.5, 5.1, and 2.5 min, respectively, and the z-value was $12.8^{\circ}C$. We estimated that B. amylo-liquefaciens isolated from spoiled wet noodles was a thermophilic species having high heat-resistance. Viable cell numbers in wet noodles and broth medium inoculated with B. amyloliquefaciens were decreased by 2-4 log cycles by combined treatment with 0.03 or 0.05% OA and 0.3% SD. These results revealed that OA combined with SD could be used as a potential agent to inhibit B. amyloliquefaciens in wet noodles.