• Food Science and Biotechnology
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• 제17권6호
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• pp.1160-1164
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• 2008

An novel amylolytic yeast, Saccharomyces cerevisiae HA 27, isolated from nuruk, displayed resistance against high sugar (50% glucose) and alcohol (15%). Maximal production of amylolytic enzyme by S. cerevisiae HA 27 was achieved on 9 days of cultivation at the optimal temperature $20^{\circ}C$ and pH 6.0. The activity of amylolytic enzyme produced by S. cerevisiae HA 27 was stable, even at $70^{\circ}C$, and over a broad pH range (4.0-11.0). Also, the amylolytic enzyme of S. cerevisiae HA 27 showed optimal activity in pH 5.0 at $50^{\circ}C$. S. cerevisiae HA 27 exhibited 6.2%(v/v) alcohol fermentation ability using starch as a carbon source.

• 한국식품과학회지
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• 제18권6호
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• pp.431-436
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• 1986

분질고구마인 원기와 점질고구마인 천미로부터 얻은 전분에 각 고구마에서 추출된 조효소와 분가수분해효소를 작용시켜 비교 검토한 결과는 다음과 같았다. 천미보다 원기에서 추출한 조효소의 전분가수분해활성이 높았으며 각 전분의 호화온도에 따른 조효소의작용으로 생성된 환원당 함량은 $70^{\circ}C$에서는 천미전분을 기질로 한 것이, $95^{\circ}C$에서는 원기 전분을 기질로 한 것이 더 높았다. 원기 전분에 대한 ${\alpha}-amylase$와 ${\beta}-amylase$ 활성은 천미전분에 대한 것보다 높았다. 효소처리 전분의 요드 반응 후의 흡광도는 생전분보다 낮았으며, 형태는 표면에서 내부로 여러 층을 갖는 구멍이 있고 둥근형이었다. 각 전분의 X-선 회절양상을 관찰한 결과 본 실험에 사용된 고구마 전분은 효소처리 후에도 생전분과 같이 Ca 형을 유지하였으며 상대적 결정도는 효소처리전분이 생전분보다 낮았다.

• 한국식품과학회지
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• 제43권5호
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• pp.570-576
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• 2011

본 연구에서는 누룩 및 조효소제 첨가 비율을 달리하여 제조한 현미식초의 유리아미노산 및 휘발성 성분에 관한 품질특성을 조사하였다. 총 유리아미노산 함량은 AV에서는 130.06 mg%로 가장 낮았고, BV, CV, DV, EV는 190 mg% 전후로 비슷한 함량을 나타내었다. 조효소제를 일부 첨가하여 제조한 현미식초(BV, CV, DV, EV)가 누룩만 첨가하여 제조한 현미식초(AV)에 비하여 필수아미노산 및 총 유리아미노산 함량이 높게 나타났다. 전자코분석 결과 발효 24일째 누룩 및 조효소제를 단독으로 사용하여 발효시킨 AV 및 EV에서 뚜렷한 향기 패턴 차이를 보였고, 누룩 및 조효소제 혼합 비율로 발효시킨 BV, CV 및 DV가 유사한 향기 패턴으로 보였다. 누룩 및 조효소제의 첨가비율에 따른 현미 식초의 주된 휘발성분은 acetic acid, 3-methyl butyl acetate, acetoin, isomayl alcohol 등의 20종으로 검출되어졌다. Alcohol류는 phenylethyl alcohol, isoamyl alcohol의 비율이 높은 것으로 나타났으며, ester류는 ethyl acetate, 3-methyl butyl acetate 비율이 높은 것으로 나타났다. 발효제로 누룩 및 조효소제의 첨가비율을 달리하였을 때 조효소제를 일부 첨가하여 제조한 현미식초(BV, CV, DV, EV)가 누룩만 첨가하여 제조한 현미식초(AV)에 비하여 초산향의 상대적 농도는 다소 감소하였으나, 관능적으로 좋은 향의 상대적 농도가 증가하였으며, 특히 조효소제만으로 발효시 이취성분들도 감소되어지거나 검출되지 않음을 볼 수 있었다.

• 한국식품영양학회지
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• 제6권1호
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• pp.1-7
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• 1993

19 Samples of koji-starters using in brewing were collected from Korea and Japan, and then 31 strains of koji-molds were isolated from them. After Identification of the Isolate, rice koji was made with each strains, and its saccharogenic activity, dextrogenic activity, proteolytic activity, acid Producing ability, browning reaction and flavor were tested. Among 31 strains of isolates, 10 strains were Identified as Asp nwamori var. kawachii, 18 strains as Asp. oryzae, 3 strains as Asp. usamii mkt. shirousamii. The koji-starters made in Korea were composed of single species of koji-mold with same strain, but those made in Japan were composed of the mixture of different two species or the mixture of different 2 ∼4 strains in same species. Judging from amylolytic and proteolytic ability by species, Asp. awamori var. kawachii H1, I1 and 11, Asp. owsae J2, L2, M2, P3 and P4, and Asp. usamii writ. shirousamii S1 were better than the others. Mold strains isolated from Korean koji-starters were much lower in amylolytic or proteolytic activity than those from Japanese koji-starters. The typical characteristics for the 3 species of koji-molds were that Asp. awamori var. kawachii was strong in acid producing ability, but week in amylolytic and proteolytic ability, that Asp. owzae had strong amylolytic activity and good aroma, but produced little amount of acid, and that Asp. usamii mut. shirousamii had strong Proteolytic activity but some off-flavor.

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

• 한국식품영양학회지
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• 제11권5호
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• pp.561-564
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• 1998

The stabilizatio of amaylolytic enzyme such as $\beta$-amylase of barley, $\beta$-amylase of wheat, $\beta$-amylase of sweet potato, $\alpha$-amylase of Bacillus licheniformis, $\alpha$-amylase of Aspergillus sp. and $\alpha$-glucosidase of Aspergillus awamori was attained by modification with periodate-oxidized soluble starch. The pH stability of modified enzyme was increased at pH 9 for $\beta$-amylase of sweet potato, pH 3~5 and 8~11 for $\beta$-amylase of barley, pH 2~3 and 7~12 for $\beta$-amylase of wheat and pH 6 for $\alpha$-glucosidase of Aspergillus awamori. Thermal stability increased 17.6% for $\alpha$-amylase of Aspergillus sp. at 6$0^{\circ}C$ for 10min, 30% for $\alpha$-amylase of Bacillus licheniformis at 10$0^{\circ}C$ for 5min and 4.5% for $\alpha$-amylase of sweet potato at 6$0^{\circ}C$ for 10min compared with those of native enzymes.

• 한국식품영양학회지
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• 제7권4호
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• pp.259-266
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• 1994

The hyperthermophilic archaebacterium Thermococcus profundus Isolated from a deep-sea hydrothermal vent system, produced several amylolytic enzymes such as extracellular amylase and pullulanase, intracellular a-1,4-91ucosidase in respone to the presence of complex carbohydrates In the growth medium. This strain showed high activities on 0.5% maltose than on complex carbohydrates One of the amylases was partially purified by ammonium sulfate precipitation, DEAE-Toyopearl chromatography. The amylase exhibited maximal activity at pH 5.5 and 80$^{\circ}C$, and was stable in the range of pH 5.5 to 9.5 and up to 80$^{\circ}C$ for 30 min. The enzyme activity was no dependence on Ca2+ and not inhibited by detergents. The amylase hydrolyzed soluble starch, amylose, amylopectin and glycogen to produce maltose and maltotriose with trace amounts of glucose, but not pullulan and ${\alpha}$-, ${\beta}$-, ${\gamma}$-cyclodextrin. Malto-oligosaccharides ranging from maltotetraose to maltoheptaose were hydrolyzed in an endo fashion.

• 미생물학회지
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• 제6권3호
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• pp.81-86
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• 1968

1. Amylolytic enzyme activities of Asp. oryzae and Asp. oryzae var. fulvus using the glucose as the carbon sources increased remarkably according to the decrease of the residual sugars. 2. The amylase productions of Asp. oryzae and Asp. oryzae var. fulvus were increased and enhanced when the organisms lave belen cultured in modified Koji media containing maltose as adaptive substrate. However, being devoid of maltose the level of amylase activities were lower and the begining of the production was prolonged. 3. The effects of C-sources on the amylase production of them were observed. The level of amylase activity varied with C-sources and their concentrations Marked increase of amylase production was afforded by starch and maltose. The effects of citric acid and tartaric acid were little or nothing. 4. Using the sucrose and lactose as the adaptive substrates both strains show the maximum amylolytic enzyme activities at the 3% concentrations of those sugars.

• 한국미생물·생명공학회지
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• 제44권3호
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• pp.376-382
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• 2016

전국에서 수집 또는 직접 제작한 누룩의 전분 분해 효소 활성을 조사하였다. 전분을 액화시키는 효소인 α-amylase 활성은 상대습도 40%, 30℃ 조건에서 제조된 누룩이 24,747.1 ± 777.7 units/mg protein으로 가장 우수하였고, glucoamylase 효소 활성은 상대습도 50%, 25℃ 조건에서 제조된 누룩이 가장 우수하였다. 전분을 분해하는 활성이 가장 우수한 누룩으로부터 곰팡이 98점을 분리하고 동정한 결과, A. oryzae 균주 26점, R. oryzae 균주 18점을 확인하였다. MBF345 명명된 R. oryzae 균주는 α-amylase 활성이 36,724.9 ± 10.2 units/mg protein이었고, glucoamylase 효소활성은 4,911.8 ± 48.1 SP로 대조구 균주 보다 각각 1.7배, 1.4배 효소 활성이 우수한 것으로 나타났으며, 이 균주를 미생물보존센터에 R. oryzae KCTC46312 균주로 기탁하였다.

• 한국작물학회지
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• 제41권5호
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• pp.542-550
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• 1996

알팔파 (Medicago sativa L.)의 예취후 재생 기간중 저장탄수화물의 이용성을 규명하기 위해 수경재배하여 개화초기에 예취한 후 재생 24일간의 뿌리내 비구조탄수화물의 함량 및 전분 분해효소의 활력을 분석한 결과는 아래와 같다. 1. 재생초기 10일간의 잎과 줄기의 재생은 매우 느리게 진행되었으며, 예취후 뿌리의 성장이 억제되었다. 2. 예취후 초기재생 10∼14일간 뿌리내 가용성 당 및 전분의 함량은 다같이 감소하였다가 이후 빠르게 회복하는 경향이었다. 3. 재생기간중 exo-amylase의 평균 활력은endo-amylase에 비해 약 400배 이상 높았다. Exo-amylase의 활력은 재생 6일차(최고수준) 까지 증가하다가 이후 감소하였다. Endo-amylase의 활력은 재생초기 4일 동안 급격히 증가하다가 이후 재생 24일차(최고수준) 까지 서서히 증가하는 경향이었다. 이상의 결과들은 알팔파의 재생초기 동안 전분 분해효소의 활력의 증가와 아울러 뿌리내 저장탄수화물은 활발히 분해되어 새로운 조직의 재생에 이 용됨을 간접적으로 제시한다.