• 한국미생물·생명공학회지
• /
• 제24권2호
• /
• pp.217-221
• /
• 1996

Various treatments of naked barley with commercial liquefying enzymes have been emploved to reduce high viscosity of naked barley in cooking as a raw material for alcohol production and to increase alcohol yield. The enzyme BAN used for cooking and liquefaction of naked barley was able to make a reduction of one third of viscosity and to enhance alcohol yield of 4 l/Ton of raw material than the T120L was. Of course, alcohol yield depended in part on the applied saccharifying enzymes. The low temperature cooking of naked barley with BAN was favorable compared with high temperature cooking for both of reducing viscosity (210 vs. 237 cp) and final alcohol yield (Yp/so: 0.397 vs. 0.395 g/g) in industrial scale.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 1976년도 제7회 학술발표회
• /
• pp.184.5-184
• /
• 1976

In the course of studies on thermostable liquefying amylase from thermostable Bacillus spp., we have isolated a strain which produces amylase activity. This strain was identified to be Bacillus stearothermophlus. The amylase of this strain demonstrated a maximum activity at 65$^{\circ}C$ and Ca$\^$＋＋/ did not improve thermostability of the enzyme although the erzyme was capable of hydrolyzing starch at temperature of 80$^{\circ}C$ and above. The maximum amount of the enzyme was product at pH 7.0, 50$^{\circ}C$.

• 한국식품영양학회지
• /
• 제1권2호
• /
• pp.43-49
• /
• 1988

Fermented barley food was produced by the combining action of an enzyme and a lactobacillus. When Lactobacillus sp. L-5 and commercial liquefying amylase from Tae Pyeong Yang Chemical Co. were selected, inoculated on steamed barley and cultivated at 37$^{\circ}C$ for 48hrs, the fermented product of good quality was obtained. In batch cultivation using rotary drum fermentor, viable cell count reached 1.1$\times$10CFU/g after 12hrs' cultivation, and specific growth rate in logarithmic phase was 0.6hr-1. Viable cell count, acidity, pH, concentration of reducing sugar and viscosity of the 48hrs' fermentation product from rotary drum fermentor was 4.3$\times$108CFU/g, 1.17%, 3.1, 10.7% and 1430cp.

• 한국미생물·생명공학회지
• /
• 제14권3호
• /
• pp.225-232
• /
• 1986

보리고추장 양조시 고추씨 및 마늘을 첨가하여 제조한 고추장의 숙성과정중의 효소활성도와 이화학적 변화 및 관능검사를 조사하였다. 고추장숙성 중 효소의 활성은 전분액화·당화효소, 중성 protease, lipase모두 증가되었고 전분액화효소를 제외하고는 숙성후기에도 효소의 잔존활성이 높았으며, 고추씨의 첨가도 효소 활성유지에 효과적이었다. pH와 적정산도는 고추씨의 첨가로 변화가 적었고, 마늘의 첨가도 숙성후기에는 큰 차이가 없었다. 총질소, 아미노태질소, 총당, 환원당은 고추씨나 마늘의 첨가로 증가되었으며, 암모니아태질소는 이들의 첨가로 숙성중기에 증가하나 숙성후기에는 큰 차이가 없었다. 알코올의 생성은 고추씨나 마늘의 첨가로 적었으며, 조지방은 고추씨의 첨가로 증가하였다. 10주 숙성 고추장의 맛, 향기 및 색은 전반적으로 마늘첨가구가 무첨가구에 비하여 우수하였다. 따라서 통고추를 이용한 보리고추장은 원료에 2％의 마늘을 첨가하므로써 품질을 개선할 수 있다.

• Applied Biological Chemistry
• /
• 제12권
• /
• pp.33-41
• /
• 1969

1. Cheatomium globosum의 밀기울 배양기에서 조효소를 추출하고 황산암모니움 염석 부분을 cellulose 분말 column으로 2개의 cellulase활성 부분(C-1, C-2)을 분리 하였다. 그 하나는 환원당 증가 활성이 강하며 (C-1) 다른 하나는 곁도 감소 활성이 강하였다. (C-2) 그러나 단백질 량은 C-1부분이 많았고 C-2 부분은 적었다. 2. 환원당 증가 활성이 강한부분 (C-1)을 DEAE-Sephadex A-25 column에서 분리할 결과 다시 2개의 성분 (C-1-1 및 C-1-2)으로 나누어 졌다. 그리고 C-1-2는 column에 강하게 흡착되었고 2M-NaCl의 용액으로 용출되었다. 이는 착색 된 것으로 봐서 C-1-1과는 아주 다른 단백질로 생각이 된다. 3. Cellulase C-1-1을 다시 Amberlite XE-64 column으로 분별하여 단일의 peak를 얻었다. 4. Cellulase C-1-1 부분의 초원심 침강계 면은 단일의 peak로 나타나고 또 자외선 홍수 spectrum도 전형적인 단백질의 흡수 spectrum을 나타 내었다. 5. Cellulase C-1-1의 최적 pH는 환원당 증가활성법으로나 점도 감소 활성법으로 다 같이 pH 4.0이였다. 6. 그리고 그의 최적 온도는 $40^{\circ}C$였다. 7. Cellulase C-1-1의 pH 안정성은 $40^{\circ}C$에서 pH 5.0 내지 pH 8.0의 범위 내였다. 8. 그리고 열안정성은 pH 4.0에서 $50^{\circ}C$ 이하였다

• 한국식품영양학회지
• /
• 제27권3호
• /
• pp.414-420
• /
• 2014

This study was performed to increase the yield and to reduce the processing times for the preparation to improve the productivity and quality of rice jochung, a traditional food in Korea. In order to evaluate the quality characteristics and yield of jochung, the viscosity, color value, mineral contents and the sensory evaluation were measured. Jochung is prepared from steamed rice (STR), wet-milled rice flour (WRF) and dry-milled rice flour (DRF) by processing methods of rice and reacting times (6 hours or 13 hours) of liquefaction and saccharification. There is commonly added liquefying enzyme for rice liquefaction (0.4%/10 kg rice, at $85{\sim}90^{\circ}C$ for 1 hour or 4 hours) and saccharogenic enzyme with malt (2.5% or 4.5%/10 kg rice, at $56{\sim}60^{\circ}C$ for 5 hours or 9 hours). The inner structural properties of WRF showed the more distinct shape regular structure of uncombined starch particles but the DRF closely maintained particles of rice flour observed by SEM. If processing times for liquefation and saccharification were reduced from 13 hours to 6 hours, the yield of jochungs prepared with WRF increased 8%, the DRF 7%, and the STR 3% respectively and the sensory evaluation as well as color values and overall desirability received high scores. The viscosity, color a and b values of jochung processed with WRF for 6 hours were lower than that processed for 13 hours. The viscosity and color a, b value and Ca content were decreased in the jochung processed with WRF or DRF for 6 hours, but Mg, P and K were increased than that of STR. Jochung processed by 0.4% liquefying enzyme and 2.5% malt with WRF for 6 hours will increase the yield, save manufacturing times and costs and will thereby enable cost-effective techniques.

• Journal of Microbiology and Biotechnology
• /
• 제17권8호
• /
• pp.1242-1248
• /
• 2007

Genomic analysis of a hyperthermophilic archaeon, Thermococcus onnurineus NA1 [1], revealed the presence of an open reading frame consisting of 1,377 bp similar to ${\alpha}$-amylases from Thermococcales, encoding a 458-residue polypeptide containing a putative 25-residue signal peptide. The mature form of the ${\alpha}$-amylase was cloned and the recombinant enzyme was characterized. The optimum activity of the enzyme occurred at $80^{\circ}C$ and pH 5.5. The enzyme showed a liquefying activity, hydrolyzing maltooligosaccharides, amylopectin, and starch to produce mainly maltose (G2) to maltoheptaose (G7), but not pullulan and cyclodextrin. Surprisingly, the enzyme was not highly thermostable, with half-life ($t_{1/2}$) values of 10 min at $90^{\circ}C$, despite the high similarity to ${\alpha}$-amylases from Pyrococcus. Factors affecting the thermostability were considered to enhance the thermo stability. The presence of $Ca^{2+}$ seemed to be critical, significantly changing $t_{1/2}$ at $90^{\circ}C$ to 153 min by the addition of 0.5 mM $Ca^{2+}$. On the other hand, the thermostability was not enhanced by the addition of $Zn^{2+}$ or other divalent metals, irrespective of the concentration. The mutagenetic study showed that the recovery of zinc-binding residues (His175 and Cys189) enhanced the thermo stability, indicating that the residues involved in metal binding is very critical for the thermostability.

• 한국미생물·생명공학회지
• /
• 제14권5호
• /
• pp.399-405
• /
• 1986

무증자 전분의 효소당화시 분쇄마찰매체를 첨가하여 분쇄마찰 효과를 주어 당화를 촉진시키는 새로운 무증자 전분 당화법을 이용하여 HFCS의 제조에 적합한 포도당 함량이 높은 고농도 당액을 얻기 위해 연구하였다. 생전분을 고농도 당화를 위해 22.5, 39, 그리고 45%(w/v)와 같이 농도를 고농도까지 증가시켜 가면서 당화시킨 결과, 분쇄마찰 반응계를 활용할 경우 39%(w/v)와 같은 높은 전분 농도에서도 효율적인 당화가 가능하였으며, 8시간 후 75%, 24시간 후에는 92% 이상이 분해되었고 이때 당 농도는 425g/L 수준에 이르렀다. 초 고농도로 전분을 투입한 경우에도 전분을 batch식으로 투입하지 않고 분할 투입하는 fed-batch식으로 분할 투입한 결과 45%(w/v)와 같은 초 고농도에서도 우수한 결과를 얻었다. 또한 고농도에서는bead size가 큰 것이 당화촉진 효과가 컸다. 생성된 당조성을 HPLC로 분석한 결과 증자법의 당조성과 거의 유사한 glucose 95%, maltose 0.7%, 그리고 higher saccharide 4.5%로써 HFCS 제조에 적합한 특성을 갖추었다. 분쇄매체의 shearing에 의한 효소실활을 검토한 바 본 실험과 같은 교반하에서는 효소가 비교적 안정하였고. 특히 $Ca^{++}$은 효소 안정화에 매우 중요한 역할을 수행하였다.

• Journal of Microbiology and Biotechnology
• /
• 제11권4호
• /
• pp.636-643
• /
• 2001

Bacillus sp. AIR-5, a strain from soil, produced an extracellular maltopentaose-forming amylase from amylose and soluble starch. This bacterium produced 8.9 g/l of maltopentaose from 40 g/l of soluble starch in a batch fermentation and the maltopentaose made up 90 % of the maltooligosaccharides produced (from maltose to maltoheptaose). The culture supernatant was concentrated using a 30 K molecular weight cut-off membrane and purified by DEAE-Cellulose and Sephadex G-150 column chromatographies. The purified protein showed one band on a native-PAGE and its molecular mass was estimated as 250 kDa. The 250-kDa protein was composed of tetramers of a 63-kDa protein. the isoelectric point of the purified protein was pH 6.9, and the optimum temperature for the enzyme activity was $45^{\circ}C$. The enzyme was quickly inactivated above $55^{\circ}C$, and showed a maximum activity at pH 8.5 and over 90% stability between a pH of 6 to 10. The putative N-terminal amino acid sequence of AIR-5 amylase, ATINNGTLMQYFEWYVPNDG, showed a 96% sequence similarity with that of BLA, a general liquefying amylase.

• 한국미생물·생명공학회지
• /
• 제19권3호
• /
• pp.290-295
• /
• 1991

Maltose 생산효소인 Fungamyl과 생전분의 알칼리성 현탁액에 고형분쇄마찰매체를 첨가교반하면서 증자액화과정을 거치지 않고 생전분으로부터 maltose를 직접 생성시키는 연구를 수행하였다. 불용성 생전분을 기질로 하는 분쇄마찰 효소반응계에서 효소반응은 증자액화된 전분을 기질로 하는 기종의 maltose 제조법과 비슷한 효소반응속도를 보였다. 그러나 24시간후 maltose 농도는 증자법을 초과하여, 생전분의 농도가 150g/l일 때 95g/l의 maltose를 얻을 수 있었고, 첨가생전분에 대한 수율은 0.60이었다. 또한 생산된 포도당, maltose, maltoriose의 농도는 각각 20, 95 그리고 13g/l였으며, maltose의 함량은 72%로서 증자법의 6%0에 비하여 매우 높았다.