• Mycobiology
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• 제34권2호
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• pp.73-78
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• 2006

Inter-specific hybridization between Pleurotus pulmonarius and P. florida was attempted through PEG-induced protoplast fusion to select a fusant. The protocol for protoplast release, regeneration and fusion in these two Pleurotus species was standardized using the variables controlling the process. The mixture of mycolytic enzymes, i.e. commercial cellulase, crude chitinase and pectinase, KCl (0.6 M) as osmotic stabilizer, pH 6 of the phosphate buffer and an incubation time of 3 hours resulted in the maximum release of protoplasts from 3-day-old mycelia of P. florida ($5.3{\sim}5.75{\times}10^{7}$ protoplasts/g) and P. pulmonarius ($5.6{\sim}6{\times}10^{7}$ protoplasts/g). The isolated protoplasts of P. florida regenerated mycelium with 3.3% regeneration efficiency while P. pulmonarius showed 4.1% efficiency of regeneration. Polyethyleneglycol (PEG)-induced fusion of protoplasts of these two species resulted in 0.28% fusion frequency. The fusant produced fruiting bodies on paddy straw but required a lower temperature of crop running ($24{\pm}2^{\circ}C$) than its parents which could fruit at $28{\pm}2^{\circ}C$. The stable fusant strain was selected by testing for the selected biochemical markers i.e. Carbendazim tolerance and utilization of the lignin degradation product, vanillin.

• KSBB Journal
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• 제17권4호
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• pp.321-325
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• 2002

광학활성 에폭사이드는 다양한 반응성으로 인하여 고부가 가치 광학활성 의약품 및 농약 합성용 중간체로 널리 이용되고 있다. 광학활성 에폭사이드는 에폭사이드 가수분해효소 (epoxide hydrolase, EH)를 이용하여 저가의 라세믹 기질에 대한 입체선택적 가수분해 반응을 통해 제조할 수 있으며, EH는 유도과정 없이 발현되고 보조인자가 필요 없으며 비교적 효소 안정성도 높아 상업적으로 유용한 효소이다 EH에 대한생화학 및 분자생물학 관련 최근 연구 결과를 바탕으로 촉매활성 증대 및 기질 선택성을 변경시킨 tailer-made형 EH 생촉매 개발이 가능할 것이며, 실규모의 비대칭 광학분할 생물공정 시스템 개발을 통해 EH에 의한 동력학적 가수분해반응을 이용한 광학활성 에폭사이드 생산기술의 상업화가 가능할 것으로 기대된다.

• Archives of Pharmacal Research
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• 제10권3호
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• pp.158-164
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• 1987

To obtain a new strain of Ganoderma lucidum by protoplast fusion technique, its protoplast formation and regeneration were studied. Several factors affecting the protoplast formation and regeneration were investigated to find their optimum conditions. The mycelium was grown for four days on the cellophane membrane placed on G. Incidum complete medium (GCM). When various commercial lytic enzymes were examined for protoplast isolation, the combination of Novozym 234 and $\beta$glucuronidase was found to be effective. An osmotic stabilizer, 0.6 M sucrose in 20 mM phosphate buffer pH 5.8, gave the highest yield of protoplasts. Three-hour incubation in shaking incubator was most suitable for releasing protoplasts. To increase the protoplast yield, pretreatment with 2-mercaptoethanol was carried out. The regeneration frequency in GCM containing 0.6M MgSO$_4$ 7$H_2O$ was shown to be 0.66%.

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.246-249
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• 2000

We investigated the production of chitin oligosaccharides using food grade papain. A solution of commercial food grade papain (FGP) was dialyzed for 12 h before measuring its chitinolytic activity. The effects of enzyme concentration, reaction temperature, and pH on the endochitinase and $\beta$-N-acetylglucosaminidase activities and the thermostability of these enzymes were investigated. In adddition, the reaction products were analyzed with gel filtration on a Bio-Gel P2. The endochitinase activity was twentyfold higher than that of $\beta$-N-acetylglucosaminidase. The optimal endochitinase activity was at pH 3.0, while the maximal $\beta$-N-acetylglucosaminidase activity was at pH 6.0. The reaction product consisted mainly of the dimer of N -acetylglucosamine, with a small amount of its trimer. Under the experimental conditions, $120{\mu}g$ of chitin oligomers were obtained with 1 mg of FGP protein after an incubation of 2 h.

• 한국환경보건학회지
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• 제31권4호
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• pp.294-300
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• 2005

Food waste can be a valuable carbon source in biological nutrient removal (BNR) systems because of high C/N and C/P ratios. However, food waste should be pretreated to promote its hydrolysis rate because hydrolysis reaction would be a rate-limiting step. This study investigates the influence of the enzymatic pretreatment on acid fermentation of food waste. Solubilization of particulate matter in food waste by using commercial enzymes was examined. The acidification efficiency and the volatile fatty acids (VFAs) production potential of enzymatically pretreated food waste were also examined. The highest volatile suspended solids (VSS) reduction was obtained with an enzyme mixture ratio of 1:2:1 of carbohydrase:protease:lipase. An optimum enzyme dosage for solubilization of food waste was $0.1\%$(V/V) with the enzyme mixture ratio of 1:2:1. In the acid fermentation of enzymatically pretreated food waste, $0.1\%$(V/V) enzyme mixture dosage for pretreatment result in the maximum VFAs production and the best VFAs fraction in soluble COD(SCOD). The VFAs production at this addition level was 3.3 times higher than that of no-enzyme added fermenter. The dominant VFAs present was n-butyrate followed by acetate.

• 한국축산식품학회지
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• 제30권2호
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• pp.223-231
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• 2010

In order to develop a new starter for fermented milk, Lactobacillus paracasei subsp. paracasei BFI46 (BFI46) obtained from new-born infant feces was investigated for physiological characteristics. Good immunomodulating activity was evident compared with commercial lactic acid bacteria starter cultures. The optimum growth temperature of BFI46 was $40^{\circ}C$ with 12 h required to reach pH 4.3. Testing with 13 different antibiotics revealed greatest sensitivity of BFI46 to penicillin- G and chloramphenicol, and heightened resistance to neomycin, kanamycin and polymyxin. BFI46 displayed higher esterase activities compared to 18 other enzymes, was comparatively tolerant to bile juice and able to survive at pH 2 for 3 h, and displayed high resistance against Escherichia coli and Salmonella Typhimurium with a survival rate of 57.14% and 96.36%, respectively. The results indicate that BFI46 could be an excellent starter culture for fermented milk with high level of immunomodulating activity.

• 한국식품영양과학회지
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• 제29권2호
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• pp.280-287
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• 2000

Generally, buckwheat has been regarded as a crop of secondary importance in many countries. In vitro functionalities of buckwheats as a food were evaluated in this study. Five of buckwheat cultivars were extracted with methanol, and the extractant were dried and lyophilized, separately. Or water soluble buckwheat components were digested with the commercial enzymes and the obtained protein hydrolysate was again fractionated by acid precipitation. The antioxidant capacity of the methanol extracts determined using Fe2+-ascorbic acid system was dependent ont the cultivars: The extract of Suwon 4 showed 3.3 times stronger activity than ascorbic acid in terms of IC50. Also, the extracts of buckwheats inhibited efficiently the activities of $\alpha$-amylase and lens aldose reductase. Buckwheat soluble protein or rutin suppressed the in vitro activities of angiotensin-converting enzyme, and the inhibitory degree depended largely on the cultivars. Buckwheat proteins exerted higher hydrophobicity being related to the sterol binding capacity than casein. The results suggested that buckwheat seeds may be desirable and functional food resources in human living in current society.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.443-461
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• 2022

This study was conducted to assess the effects of the dietary supplementation of riboflavin (as a bile salt hydrolase [BSH] inhibitor) and Bacillus subtilis on growth performance and woody breast of male broilers challenged with Eimeria spp. Intestinal bacteria, including supplemented probiotics, can produce BSH enzymes that deconjugate conjugated bile salts and reduce fat digestion. A 3 × 2 × 2 (riboflavin × Bacillus subtilis × Eimeria spp. challenge) factorial arrangement of treatments in randomized complete block design was used. On d 14, birds were gavaged with 20× doses of commercial cocci vaccine (Coccivac^R -B52, Merck Animal Health, Omaha, NE). Dietary treatment of riboflavin and B. subtilis did not affect body weight (BW), body weight gain (BWG), and feed conversion (FCR) d 0 to 14 and overall d 0 to 41. Eimeria spp challenge reduced BWG, feed intake (FI), and increased FCR between d 14 to 28, but increased BWG and lowered FCR between d 28 to 35. There were no effects of the Eimeria spp. challenge on the overall d 0 to 41 FCR and FI, but BWG was reduced. Eimeria spp. challenge increased the abdominal fat pad weight and slight woody breast incidences on processed birds on d 42. Dietary inclusion of B. subtilis and riboflavin at tested levels did not help birds to mitigate the negative impact of Eimeria spp. challenge to enhance the growth performance.

• 한국응용과학기술학회지
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• 제36권3호
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• pp.1018-1027
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• 2019

천연물 유래 저분자 펩타이드들은 항산화, 고혈압 완화, 면역조절, 진통완화 및 항균작용 등 생리활성이 있는 것으로 알려져 왔다. 본 연구는 연산오계육 단백질을 상업용 프로티아제(alcalase, bromelain, flavourzyme, neutrase, papain, protamex)를 이용하여 저분자 펩타이드를 생산하고 항산화 활성(DPPH 소거능, 슈퍼옥사이드 라디칼 소거능, 하이드록시 라디칼 소거능 및 금속 킬레이션 능력), 펩타이드의 구성 아미노산 및 분자량을 분석하였다. 효소반응은 효소반응기에 다진 오계육 슬러리 50 g와 단백질 효소 2%(w/v)를 넣고 pH 6 와 온도 $60^{\circ}C$ 조건에서 2시간 반응을 하였다. 반응 후 가수분해도(%)의 범위는 $36.65{\pm}4.10%$에서 $70.75{\pm}5.29%$ 사이의 범위를 보여주었는데 protamex의 가수분해도는 46.3%로 가장 높았으며, papain hydrolysate가 $70.75{\pm}5.29%$로 가장 높은 값을 보여주었으며, 반면에 alcalase hydrolysate가 $36.65{\pm}4.10%$로 가장 낮은 값을 보여주었다. DPPH 라디칼 소거능은 bromelain 처리 저분자 펩타이드가 가장 높게 나타났고, alcalase 처리 펩타이드에서 소거능이 가장 낮게 나타났다. 슈퍼옥사이드 라디칼 소거능 역시 bromelain 처리 저분자 펩타이드가 50% 이상의 가장 높은 라디칼 소거능을 보여주었다. 하이드록시 라디칼 소거능은 약 16.73에서 69.16% 사이의 분포를 보여 주었는데 bromelain 처리 저분자 펩타이드에서 가장 높게 나타났다. $Fe^{2+}$ 킬레이션 능력은 약 17.85에서 47.84% 사이의 분포를 보여 주었다. hydrolysate들의 킬레이션 능력은 사용 효소들에 상관없이 큰 차이점이 없었다. 아미노산의 분석결과 alcalase, bromelain, flavourzyme, neutrase, papain, protamex 효소 가수분해 시켰을 때 차이점을 보여 주었고 가장 많은 아미노산은 glutamic acid이었다. 효소 hydrolysate들의 분자량의 분포는 처리 효소에 따라 분자량의 분포가 다르게 나타났지만 300-2,000 Da 범위에 있었다.

• 한국식품과학회지
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• 제30권2호
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• pp.245-252
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• 1998

키토산 올리고당 생산에 이용 가능한 경제성 있는 키토산 분해 효소를 탐색하였다. Cellulase, ${\beta}-1,4-glucosidase,\;protease$ 및 상업용 효소류를 대상으로 조제 키토산에 대한 분해력을 시험한 결과 Trichoderma viride, T. reesei 유래의 cellulase 및 상업용 효소인 Celluclast (T. reesei 유래 cellulase)가 우수한 키토산 분해능력을 나타내었다. 키토산에 대한 반응성은 T, reesei 유래 cellulase가 T. viride 유래 cellulase 보다 강하였으며 이들의 적정 키토산 분해조건은 pH 5.0이었고 적정 온도는 T. viride 유래 celluclast는 $45^{\circ}C$, T. reesei 유래 cellulase 및 Celluclast는 $55^{\circ}C$로 나타났다. 또한 dose reponse시험에서 이들 효소 모두 enz./chitosan비=0.1이 적절하였으며 T. reesei 유래 효소 및 Celluclast는 키토산 농도가 3%일 때 최대의 활성을 나타내었다. 한편, 상업용 효소인 Celluclast를 이용한 키토산 올리고당의 생산 가능성을 시험하기 위하여 3% 키토산 용액(310cp)에 Celluclast를 1% 첨가하고 $pH\;5.0,\;55^{\circ}C$에서 시간별로 반응시켰을 때, 점도는 초기30분경에 5.51cp로 98% 이상 감소하였으며 50% ethanol 가용물의 수율은 분해 15시간에 70%로 최대를 보였다. 총환원당의 함량은 분해시간이 경과함에 따라 증가하였고 반응 2시간부터 13.5% 내외의 수준을 유지하였다. 올리고당의 조성은 15시간 분해물에서 균일한 분포와 높은 함량을 보였으며 항종 양활성을 나타내는 것으로 알려진 6량체 키토산 올리고당의 생성량은 기존의 산 분해방법의 약 4배에 해당되는 8.0%로 나타났다. 따라서 T. viride 및 T. ressei 유래의 cellulase는 99% 이상의 탈아세틸화도를 가지는 키토산에 대하여 분해활성을 나타내고 특히 T. reesei유래의 상업용효소는 지금까지 효소가격이 너무 높아 활용되지 못한 chitosanase를 대신하여 키토산 올리고당을 경제성 높게 생산하는 데 이용될 수 있을 것으로 기대되었다.