• 한국미생물·생명공학회지
• /
• 제13권3호
• /
• pp.223-232
• /
• 1985

한국의 토양에서 분리한 균 중 bacterial $\alpha$-amylase에 저해효과가 있는 균주를 분리하여 DMC-47 균주라 명명하였고, 이 균주는 Streptomyces 속의 균임을 확인하였다. 이 균주를 옥수수 전분 배지에서 진탕 배양한 결과 4일후에 최대 저해 효과를 나타내었다. 이 균주가 생성한 저해물질은 bacterial $\alpha$-amylase, pancreatic $\alpha$-amylase, salivary $\alpha$-amylase, glucoamylase에 저해효과를 보였고, $\beta$-amylase 에는 저해효과가 없었다.

• 한국식품영양학회지
• /
• 제9권1호
• /
• pp.85-91
• /
• 1996

B-amylase(EC 3.2.1.2) was isolated from the root of arrowroot(Peuria thunbergiana Bentham) with distilled water and then fractionated with ammonium sulfate. Crude extract was partially purified by ion exchange chromatography and gel filtration. The enzymatic properties of partially purified $\beta$-amylase were as follows, the enzyme was fractionated with ammonium sulfate between 0.2 and 0.4 saturation, and showed the typical reaction properties of B-amylase producing only maltose from starch. Optinum pH and temperature were pH 6.5, $50^{\circ}C$ respectively. The activity of the enzyme had proportional relations with enzyme protein concentration below 4mg, and had Michaelis constant of 66.7mg% for soluble starch. The enzyme was inhibited by some metal louts such as silver, cadmium, mercury, aluminum, iron and copper.

• Journal of Microbiology
• /
• 제42권4호
• /
• pp.319-327
• /
• 2004

An additional amylase, besides the typical $\alpha-amylase,$ was detected for the first time in the cytoplasm of B. subtilis SUH4-2, an isolate from Korean soil. The corresponding gene (bbmA) encoded a malto­genic amylase (MAase) and its sequence was almost identical to the yvdF gene of B. subtilis 168, whose function was unknown. Southern blot analysis using bbmA as the probe indicated that this gene was ubiquitous among various B. subtilis strains. In an effort to understand the physiological function of the bbmA gene in B. subtilis, the expression pattern of the gene was monitored by measuring the $\beta-galactosidase$ activity produced from the bbmA promoter fused to the amino terminus of the lacZ struc­tural gene, which was then integrated into the amyE locus on the B. subtilis 168 chromosome. The pro­moter was induced during the mid-log phase and fully expressed at the early stationary phase in defined media containing $\beta--cyclodextrin\;(\beta-CD),$ maltose, or starch. On the other hand, it was kept repressed in the presence of glucose, fructose, sucrose, or glycerol, suggesting that catabolite repression might be involved in the expression of the gene. Production of the $\beta-CD$ hydrolyzing activity was impaired by the spo0A mutation in B. subtilis 168, indicating the involvement of an additional regu­latory system exerting control on the promoter. Inactivation of yvdF resulted in a significant decrease of the $\beta-CD$ hydrolyzing activity, if not all. This result implied the presence of an additional enzyme(s) that is capable of hydrolyzing $\beta-CD$ in B. subtilis 168. Based on the results, MAase encoded by bbmA is likely to be involved in maltose and $\beta-CD$ utilization when other sugars, which are readily usable as an energy source, are not available during the stationary phase.

• KSBB Journal
• /
• 제22권2호
• /
• pp.114-118
• /
• 2007

제주도 토양 샘플에서 분리한 amylase 생산균 15번 균주는 100 mL flask level와 10 L 생물반응기에서 T. inhamatum KSJ1의 FPpase, amylase 효소활성과 거의 비슷하였으며, flask level에서 두 균주의 xylanase, avicelase, CMCase, Gluco-amylase, $\beta$-amylase의 효소활성 및 음식물쓰레기의 당화능력도 모두 거의 비슷하였다. 두 균주를 YMEA 고체배지와 광학현미경으로 그 형태학적 특징을 관찰한 결과 T. inhamatum KSJ1이 녹색빛을 띠는 것과는 달리 amylase 생산균 15번 균주는 황색빛을 띠는 사상균으로 확인되었으며, 두 균주는 동일한 균은 아니지만 동일한 속으로 사료된다.

• 미생물학회지
• /
• 제40권3호
• /
• pp.230-231
• /
• 2004

꽃송이버섯(Sparassis crispa DSMZ 5201)의 균사를 사용하여 균사외 효소활성을 측정하였다. Yeast-malt extract-glucose 배지를 사용하여 $24^{\circ}C$에서 15일간 배양 후 배양여액을 조효소원으로 사용하였을 때, $\alpha$-amylase효소의 활성은 44.27 unit/$mg{\cdot}protein$이었다. 배양여액 중의 Protease, CMCase, $\beta$-glucosidase, chitinase 및 exo-$\beta$-1,4-glucanase의 세포외 효소활성은 상대적으로 높았으나, xylanase 효소활성은 낮게 나타났다.

• 약학회지
• /
• 제6권2호
• /
• pp.18-22
• /
• 1962

Purified preparation of .betha.-amylase is obtained from radish root by the means of fractional precipitation with ammonium sulfate. Purified preparation saccharifies the starch, .betha.-maltose being formed. Dextrinization in the true sense does not take place. Hydrolysis ceases when approximately 50% of the theoretical yield of maltose is obtained and there remains a substance (to be .betha.-limit dextrin) which gives a blue-violet with iodine, no glucose being formed. Stability of preparation is optimal at pH 4-9 and more completely inactivated at 65.deg. in fifteen minutes. .betha.-Amylase of radish exhibits optimal activity at and near pH 5.0, which varied depending upon the buffer. Calcium and chloride ions do not effect the activities of enzyme. The results of experiments with oxidizing, alkylating and mercaptide-forming reagents which have been reported to be specific for sulfhydryl groups confirm that free sulfhydryl groups are essential to the activity of .betha.-amylase from radish.

• Food Science and Biotechnology
• /
• 제17권3호
• /
• pp.519-526
• /
• 2008

To improve the quality of traditional kochujang, strains with high protease and amylase activity were isolated and identified from Sunchang traditional kochujang. Twenty-three strains strongly producing protease and 16 strains strongly producing $\alpha$- and $\beta$-amylase were isolated by using 1% isolated soy protein agar medium and 2% starch agar medium, respectively. Protease activities of the IA7, I5, and IA2 strain were 22.5, 21.2, and 20.6 unit/mL, respectively, and were higher than those of the other strains. Stains with high $\alpha$-amylase activity included K9 (967.8 unit/mL), K14 (828.3 unit/mL), K13 (662.5 unit/mL), K8 (601.5 unit/mL), and K11 (405.9 unit/mL). The $\beta$-amylase activity of the K11 strain was the highest, 34.3 unit/mL, among the isolated strains. Based on morphological, physiological properties, and API 50CHB-kit test for assimilation of 49 carbohydrates, 8 strains selected according to protease, $\alpha$-amylase, and $\beta$-amylase activities were tentatively identified as Bacillus megaterium (IA2), Bacillus subtilis (IA7, 15), Bacillus amyloliquefaciens (K8, K9, K11, and K13), and Bacillus stearothermophillus (K14). The IA7, 15, and K11 strains were finally identified as B. subtilis (99% ID) based on 16S rDNA sequencing.

• 한국작물학회지
• /
• 제39권2호
• /
• pp.139-145
• /
• 1994

보리(Hordeum vulgare L.) 품종인 백동을 공시하여 Polyethylene glycol로 배지의 수분 potential을 0, -5bar, -10bar, -15bar, -200bar로 조절하여 종자를 침지후 초기의 발아율, 발아속도, 호흡계수, $\beta$-amylase 활성과 환원당, 종자의 생건비 등을 조사하여 발아에 미치는 수분부족의 영향을 시험한 결과를 요약하면 다음과 같다. 1. 수분이 부족할 수록 발아율의 감소 및 발아속도 지연이 극심하였다. 2. 호흡계수(Respiratory quotient :R.Q.)는 배지의 수분 potential이 낮아짐에 따라 점차 증가한다. 3. $\beta$-amylase의 활성은 배지의 수분potential이 높아짐에 따라 높아지고 환원당량도 많아지는데 이는 종실이 충분한 수분을 흡수하지 못한 상태에서 흡수된 수분중 상당량이 세포의 구조적 수분이나 구조유지에 사용되어지기 때문이다. 4. 흡습종자의 생건비는 배지의 수분potential이 높아짐에 따라 낮아지나 심한 수분부족에 처하게 되면 도리어 상승한다. 5. 배지의 수분 potential이 -10bar이상으로 유지되어야 종자가 정상적인 발아를 하며 초기생육도 왕성하게 유지될 수 있겠다.

• Journal of Microbiology and Biotechnology
• /
• 제9권5호
• /
• pp.619-623
• /
• 1999

The C-terminal starch-binding domain of Bacillus cereus $\beta$-amylase expressed in Escherichia coli was purified and crystallized using the vapor diffusion method. The crystals obtained belong to a space group of $P3_2$ 21 with cell dimensions, a=b=60.20${\AA},\; c=64.92{\AA},\; and \; \gamma = 120^{\circ}$ The structure was determined by the molecular replacement method and refined at 1.95 ${\AA}$, with R-factors of 0.181. The final model of the starch-binding domain comprised 99 amino acid residues and 108 water molecules. The starch-binding domain had a secondary structure of two 4-stranded antiparallel p-sheets similar to domain E of cyclodextrin glucanotransferase and the C-terminal starch-binding domain of glucoamylase. A comparison of the structures of these starch-binding domains revealed that the separated starch-binding domain of Bacillus cereus $\beta-Amylase$had only one starch-binding site (site 1) in contrast to two sites (site 1 and site 2) reported in the domains of cyclodextrin glucanotransferase and glucoamylase.

• 동아시아식생활학회지
• /
• 제25권1호
• /
• pp.139-145
• /
• 2015

본 연구에는 메밀을 ${\alpha}$-amylase, ${\beta}$-amylase, glucoamylase 세 종류의 효소로 당화한 결과, 당도와 rutin, quercetin, 총 폴리페놀 함량이 증가하였고, 항산화 활성이 개선됨을 확인하였다. 당화 전 약 $1^{\circ}Brix$를 나타내던 메밀은 ${\alpha}$-amylase, ${\beta}$-amylase, glucoamylase로 당화하였을 때 최고 $10.27^{\circ}Brix$, $5.13^{\circ}Brix$, $11.13^{\circ}Brix$를 각각 나타내었다. Rutin과 quercetin의 함량도 당화 전보다 당화를 거치면서 증가하는 경향을 나타내었으며, ${\alpha}$-amylase로 당화하였을 때 rutin은 1.76배, quercetin은 2.09배 증가하였으며, ${\beta}$-amylase로 당화하였을 때 rutin은 1.58배 증가하였으며, glucoamylase로 당화하였을 때 rutin은 3.36배, quercetin은 6.58배 증가하였다. 총 폴리페놀과 DPPH radical 소거능을 측정한 결과, 당화를 하기 전과 비교하여 당화 후 총 폴리페놀 함량과 DPPH radical 소거능이 유의하게 증가하였다. 이러한 결과를 바탕으로 메밀의 당화는 메밀에 함유되어 있는 기능성 성분을 증가시켜 기능성 식품으로의 개발가능성을 높이는 것으로 판단된다.