천연발효종 유래 효모(Saccharomyces cerevisiae GDO Y45)의 분리 및 동정

심규광 ( Kyu-kwang Shim ),강동오 ( Dong-oh Kang ) 전북대학교 농업과학기술연구소 2023 농업생명과학연구 Vol.54 No.2

Strong fermentative yeasts were isolated during the preparation of natural sourdough, a continuous fermentation sourdough for Korean wheat powder. Colonies selected through the dilution plate process strongly formed black color in YA medium containing esculine, are yeasts that do not decompose protein components (casein), and new yeasts with strong fermentation power were selected through several repetitive processes. The selected strains have a large diameter of colonies formed due to their rapid growth rate, are yeasts that degrade cellulose, and are a new yeasts that do not degrade protein components. We finally selected GDO No. Y36, Y40, and Y45 among yeasts with repeatedly good swelling and strong alcohol odor during our wheat fermentation process and little odor of Korean wheat powder. As a result of analyzing the three contaminants that cause odor during the manufacture of natural sourdough, all had strong proteolytic power and fast growth rate, and all of them were identified as Bacillus spp. The results of examining the fermentation power of our wheat by preparing an aerobic liquid culture starter by selected yeast are as follows. In the process of fermenting the yeast culture solution and Korean wheat by mixing the same amount, fermentation proceeds actively after the third fermentation of Korean wheat (day 3). From then on, if the swelling of the fermentation dough is removed bubble space when the maximum swelling is formed in the fermentation of Korean wheat, the maximum swelling is repeated after an average of 3.4 hours. In the third sourdough of our Korean wheat using aerobic cultures of new yeast, it was found to be fermented 2.8-3.9 times the base volume. Without commercial yeast, new yeast alone has good swelling and can be baked, and all three strains were identified as Saccharomyces cerevisiae. S. cerevisiae GDO No. Y36, Y40, and Y45 isolated in this study are useful methods for the manufacture of natural sourdough of baking by manufacturing middle and large scale volume aerobic liquid culture starters. Among them, strains of S. cerevisiae GDO No. Y45 yeast have been deposited in KCTC (KCTC15481BP).

국산 호밀 유래의 신규 효모(Saccharomyces cerevisiae)를 이용한 호기적 배양액 스타터와 밑반죽에 의한 제빵 연구

심규광 ( Kyu Kwang Shim ),강동오 ( Dong Oh Kang ),최윤진 ( Yoon Jin Choi ) 전북대학교 농업과학기술연구소 2024 농업생명과학연구 Vol.55 No.1

To utilize the aerobic liquid culture starter, GDO Yeast No. Y35, Y36, Y40 and Y45, etc., pure-separated yeasts (Saccharomyces cerevisiae), were finally selected. Aerobic liquid culture starters by new yeast were prepared, and the third Korean wheat base dough was prepared, and this fermentation was performed to bake. The net structure was well formed during the Korean wheat fermentation process using new yeasts. During the fermentation process of Korean wheat, it was carried out in an incubator with a temperature of 30 to 32℃, and the degree of swelling was increased by 2.5 to 3.9 times in the third time of fermentation (day 3). After maximum inflation, when the fermentation dough was stirred and returned to the ground state, the swelling was repeatedly well formed after an average of 3 to 4 hrs. The culture of independent colony formed on dilution plates of commercial dry yeast(control) and the aerobic yeast of GDO No. Y45 (KCTC15481BP) of this study(temperature 30 to 32℃) was good for swelling of the fermentation dough from the third (day 3) of Korean wheat dough fermentation. The pattern of commercial yeast origin and the swelling of the new GDO No. Y45 in Korean wheat fermentation was almost similar. There was no problem with baking by Korean wheat use by liquid culture starters derived from this new yeast GDO No. Y45. Baking of fermented dough performed at a fermentation temperature of 30~32℃ had a relatively strong sour taste compared to the origin of commercial dry yeast. The use of yeast cultures as anaerobic after aerobic liquid cultures resulted in large deviations in inflatability. In baking using new yeasts GDO No. Y35, Y40, etc., baking was possible without using any commercial yeast.

표고 액체종균 배양시 배지와 균사체의 양분변화

심규광 ( Kyu Kwang Shim ),유영진 ( Young Jin Yoo ),구창덕 ( Chang Duck Koo ),김명곤 ( Myung Kon Kim ) 한국균학회 2014 Mycobiology Vol.42 No.2

Lentinula edodes liquid spawn growth under explosive aeration (supplying air with tiny bubbles) and soybean meal addition to liquid culture medium were investigated in terms of mycelial growth and residual free sugar content. The two treatments were effective for homogeneous culturing of mycelial spawn and for separating colonies during multiplication after an exponential growth period without limiting sustaining nitrogen nutrients. The mycelial growth and carbon dioxide concentration were greatest on the 13th day since the inoculation. At 12th day, however, free sugars were almost depleted in the upper part of the liquid medium. Total nitrogen content within precipitated mycelia was the highest at the 13th day. Chitin and sucrose contents in the mycelia were the highest at the 18th day, but ergosterol content became highest at 22 days. These results suggest that Lentinula edodes liquid spawn is ready in 18 days after inoculation.

아그배 Peroxidase의 정제 및 특성

양희천(Hee-Cheon Yang),손희숙(Hee-Suk Son),심규광(Kyu-Kwang Shim),오찬호(Chan-Ho Oh),최동성(Dong-Seong Choi) 한국식품영양과학회 1992 한국식품영양과학회지 Vol.21 No.1

아그배로 부터 아세톤 침전, DEAE-cellulose 칼럼 크로마토그라피, Ultro-AcA 54겔여과의 과정을 거쳐 peroxidase를 분리 정제하고, 그의 특성을 조사하였다. 아그배peroxidase의 반응 최적 pH는 4.5, 반응 최적 온도는 80℃이었고, 30℃ 이하의 온도와 pH 5.0에서 안정하였으며, 80℃에서 15분간 보존했을 때 거의 불활성화되었다. OPDA에 높은 활성을 나타내었으나, phenol류 기질에 대해서는 약간의 활성을 나타내었으며, OPDA와 H₂O₂에 대한 Km치는 각각 1. 65mM, 7.97mM이었다. 아그배 peroxidase에 대한 저해작용은 L-ascorbic acid와 sodium L-ascorbate가 가장 컸고, 금속이온 중 Mn^(2+)만이 5mM 농도에서 효소의 활성을 증가시켰다. Peroxidase in the fruit of Malus sieboldii (Regel) Rehder was partially purified by DEAE-cellulose column chromatography and Ultro-AcA 54 gel filtration. The optimum pH of peroxidase was 4.5 and optimum temperature was 80℃. The enzyme was stable at pH 5.0 and below 30℃, and inactivated by heat treatment at 80℃ for 15min. In the presence of 30mM H₂O₂ Km value on o-phenylenediamine as substrate was 1.65mM, and in the presence of 10mM o-phenylenediamine Km value on H₂O₂ was 7.97mM. L-Ascorbic acid and sodium L-ascorbate greatly inhibited the enzyme activity and among several metal ions Mn^(2+) only increased the activity at 5mM.

Cyclodextrin 분해효소의 정제 및 그 특성

문영희,김용휘,심규광 한국농화학회 1990 Applied Biological Chemistry (Appl Biol Chem) Vol.33 No.1

Cyclodextrin hydrolase from Bacallus stearodhermophilus KFCC 21203 was purified and the properties of the purified enzyme were investigated. The enzyme was purified 15 folds with 77% recovery by ammonium sulfate fractionation, DEAE-cellulose chromatography, and Ultro AcA 34 gel filtration. The specific activity and the molecular weight of the enzyme were 1.30 units/㎎ protein and about 29,500, respectively. The maximum activity of the enzyme was shown at 55℃ and pH 5.5. However, stable temperature and pH were 40 ℃ and 5.0∼8.0, respectively. The Km value for γ-cyclodextrin was 3.78 × 10^(-3) M. The degradation activity of the enzyme was selectively high for γ-cyclodextrin, and very low for β-cyclodextrin, but not for α-cyclodextrin. The decomposed products of γ-cyclodextrin were mainly glucose and maltose, and a little mlatotriose. The activity of the enzyme was very high for amylose, potato starch, corn starch, amylopectin and maltooligomer, and relatively high for glycogen and dextrin. The decomposed products of them were mainly glucose and maltose.