• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.71-77
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• 1998

The strain of Serratia marcescens QM B1466 produces selectively large amount of chitinolytic enzymes (about 1mg/L medium). Enzymatic hydrolysis of chitin to N-acetyl-${\beta}$-D-glucosamine (NAG) was performed with a system consisting of two hydrolases (chitinase and chitobiase) produced by optimization of a microbial host consuming chitin particles. For the development of Large-scale biological process for the production of NAG from chitinaceous waste, the selection and optimization of a microbial host, particle size of crab/shrimp chitin sources and initial induction time using chitin as a sole carbon source on chitinase/chitobiase production and NAG production were examined. Crab-shell chitin(1.5%) treated by dilute acid and , ball-milled with a normal diameter less than 250m gave the highest chitinase activity over a 7 days culture. Crude chitinase/ chitobiase solution obtained in a 10 L fed-batch fermentation showed a maximum activities of 23.6 U/mL and 5.1 U/mL, respectively with a feeding time of 3 hrs, near pH 8.5 at 30$^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.207-214
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• 2012

Laccase- and peroxidase-free tyrosinase has commercial importance in the production of L-3, 4-dihydroxyphenylalanine (L-DOPA), which is mainly used in the treatment of Parkinson's disease. In the present study, isolation of an actinomycetes microbial strain capable of producing only tyrosinase is reported. Among all soil isolates, three individual colonies revealed black color around the colony in the presence of tyrosine. Further screening for laccase and peroxidase activities using syringaldazine denoted that one of the isolates, designated as RSP-T1, is laccase and peroxidase negative and produces only tyrosinase. The microbe was authenticated as Streptomyces antibioticus based on 16S ribotyping. Effective growth of this isolate was noticed with the use of medium (pH 5.5) containing casein acid hydrolysate (10.0 g/l), $K_2HPO_4$ (5.0 g/l), $MgSO_4$ (0.25 g/l), L-tyrosine (1.0 g/l), and agar (15 g/l). The scanning electron micrograph depicted that the microbe is highly branched and filamentous in nature. The enzyme production was positively regulated in the presence of copper sulfate. The impact of different fermentation parameters on tyrosinase production depicted that the maximized enzyme titer values were observed when this isolate was grown at 6.5 pH and at $30^{\circ}C$ temperature under agitated conditions (220 rpm). Among all the studied physiological parameters, agitation played a significant role on tyrosinase production. Upon optimization of the parameters, the yield of tyrosinase was improved more than 100% compared with the initial yield.

• 한국미생물·생명공학회지
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• 제49권1호
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• pp.45-56
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• 2021

Improved amylases were developed from protoplast fusants of two amylase-producing Aspergillus species. Twenty regenerated fusants were screened for amylase production using Remazol Brilliant Blue agar. Crude enzyme extracts produced by solid state fermentation of rice bran were assayed for activity. Three variable factors (temperature, pH and enzyme type) were optimized to increase the amylase activity of the parents and selected fusants using rice bran medium and solid state fermentation. Analysis of this optimization was completed using the Central Composite Design (CCD) of the Response Surface Methodology (RSM). Amylase activity assays conducted at room temperature and 80℃ demonstrated that Aspergillus designates, T5 (920.21 U/ml, 966.67 U/ml), T13 (430 U/ml, 1011.11 U/ml) and T14 (500.63 U/ml, 1012.00 U/ml) all exhibited improved function making them the preferred fusants. Amylases produced from these fusants were observed to be active over the entire pH range evaluated in this study. Fusants T5 and T14 demonstrated optimal activity under acidic and alkaline conditions, respectively. Fusants T13 and T14 produced the most amylase at 72 h while parents TA, TC and fusant T5 produced the most amylase after 96 h of incubation. Response surface methodology examinations revealed that the enzyme from fusant T5 was the optimal enzyme demonstrating the highest activity (1055.17 U/ml) at pH 4 and a temperature of 40℃. This enzyme lost activity with further increases in temperature. Starch hydrolysis using fusant T5 gave the highest yield of glucose (1.6158 g/100 ml). The significant activities of the selected fusants at 28 ± 2℃ and 80℃ and the higher sugar yields from cassava starch hydrolysis over their parental strains indicate that it is possible to improve amylase activity using the protoplast fusion technique.

• 한국식품영양학회지
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• 제18권1호
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• pp.39-47
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• 2005

청국장으로부터 분리한 균을 이용하여 fibrin을 분해 효소활성이 우수한 균주 Bacillus subtilis MG410을 분리한 균주를 이용하여 fibrinolytic enzyme의 생성을 위한 최적 배지 조건을 확립하고자 하였다. 최적 배지 조성은 탄소원 cellobiose 0.5% 첨가시 control보다 균의 성장은 0.5배, 효소 활성은 9배 정도 높은 효과를 보였고, 단당류인 glucose를 첨가시에는 균의 성장은 다소 높았으나 효소활성은 높지 않은 수치를 나타냈다. 질소원으로 soybean meal, soybean peptone을 각각 첨가시 기본배지에서 보다 균의 성장과 효소활성이 높게 나타났고, bacto peptone은 균의 성장은 낮았지만 효소 활성은 높게 나타났다. 그 중 soybean meal을 첨가시에 가장 높은 균의 성장과 효소활성이 나타났다. 질소원 soybean meal 2%를 첨가시 control보다 균의 성장은 6배, 효소 활성은 0.5배 높은 효과를 보였다. 무기질원으로는 Na₂HPO₄·12H₂O을 첨가시 효소생산이 가장 높게 나타났으며, CaCl₂, K₂HPO₄, KH₂PO₄ 첨가시에는 효소 생산에 높은 효과를 보였으나 CuSO₄·5H₂O, CoCl₂·6H₂O 첨가시에는 효소생산 및 균체 생육이 강력히 억제되었다. pH에서는 pH 5가 control보다는 균의 성장은 5배, 효소 활성은 10배 이상 높은 효과를 보였다. 따라서 최적 배지 조성은 탄소원 cellobiose 0.5%, 질소원 soybean meal 2%, 무기질원 Na₂HPO₄·12H₂O 0.02%, pH 5로 조성되었다. 이 조건하에서 배양 37℃, 48시간, 150 rpm에서 효소 생성이 가장 높은 것으로 나타났다.

• 생명과학회지
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• 제14권4호
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• pp.608-613
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• 2004

Pyrimidine nucleoade N-ribosidase (pyrimidine 5'-nucleotide phosphoribo (deoxyribo) hydrolase/ pyrimidine 5'-nucleotide nucleosidase, EC 3.2.2.10)는 CMP와 UMP를 직접 분해하여 cytosine과 uracil를 생성하는 가수분해효소이다. 본 연구에서는 Pseudomonas oleovorans ATCC 8062의 생육과 pyrimidine nu-cleotide N-ribosidase생성에 미치는 탄소원과 질소원의 영향 및 생육인자 등에 대하여 검토했다. 효소생성의 최적배양조건은 2% fumarate, 1.5% peptone, 5% corn steep liquor (CSL)과 1% ammonium chloride의 배지조성(초기 pH 7.0)으로 $28^{\circ}C$, 48시간 진탕 배양이 양호했다. 효소의 활성은 생육이 최대에 도달하는 정지기 후기에 최대에 도달하며, 그 이후부터 급속히 불활성화 되었다. P. oleovorans의 pyrimidine nucleocde N-ribosidase는 UMP에 의하여 유도 생성되지 않으므로 구성효소이며, 내생효소였다.

• Journal of Microbiology and Biotechnology
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• 제20권11호
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• pp.1597-1602
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• 2010

Chitinase is one of the most important mycolytic enzymes with industrial significance. This enzyme is produced by a number of organisms including bacteria. In this study, we describe the optimization of media components with increased production of chitinase for the selected bacteria, Stenotrophomonas maltophilia, isolated from soil. Different components of the defined media responsible for influencing chitinase secretion by the bacterial isolate were screened using Plackett-Burman experimental design and were further optimized by Box-Behnken factorial design of response surface methodology in liquid culture. Maximum chitinase production was predicted in medium containing 4.94 g/l chitin, 5.56 g/l maltose, 0.62 g/l yeast extract, 1.33 g/l $KH_2PO_4$, and 0.65 g/l $MgSO_4{\cdot}7H_2O$ using response surface plots and the point prediction tool of the DESIGN EXPERT 7.1.6 (Stat-Ease, USA) software.

• Journal of Ginseng Research
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• 제34권1호
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• pp.68-75
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• 2010

This study sought to optimize the extraction and enzymatic treatment conditions of Panax ginseng leaves, stems, and roots for the production of fermented ginseng. The optimization enhanced the extraction of total saccharide, a nutrient and growth-activating factor for Lactobacillus bacteria. The hydrolysis of ginseng leaves, stems, and roots was tested with eight enzymes (Pentopan, Promozyme, Celluclast, Ultraflo, Pectinex, Ceremix, Viscozyme, and Tunicase). The enzymatic hydrolysis conditions were statistically optimized by the experimental design. Optimal particle size of ginseng raw material was <0.15 mm, and optimal hydrolysis occurred at a pH of 5.0-5.5, a reaction temperature of 55-$60^{\circ}C$, a Ceremix concentration of 1%, and a reaction time of 2 hr. Ceremix produced the highest dry matter yield and total saccharide extraction. Ginseng leaves were found to be the most suitable raw material for the production of fermented ginseng because they have higher carbohydrate and crude saponin contents than ginseng roots.

• 한국축산식품학회지
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• 제30권2호
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• pp.286-290
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• 2010

본 연구를 통해 난백 단백질인 ovotransferrin 및 가수분해물의 항고혈압 효과를 얻을 수 있는 ACE 저해효과가 최초로 확인되었다. Ovotransferrin과 산 분해 및 효소 가수분해물의 ACE 저해효과 순서는 trypsin>pepsin>산 분해순인 것으로 나타났다. 따라서, trypsin에 의해 가수분해되어 생산된 가수분해물이 가장 큰 ACE 저해효과(60.2%)를 나타내는 것으로 확인되었으며, 이 결과를 토대로 trypsin에 의한 가수분해물의 최적화 연구를 수행하였다. ACE 저해효과를 효소 반응시간에 따른 생산을 검토한 결과, 7시간 일 때 64%로 가장 높게 나타났으며, 7시간을 반응시간으로 최적화 실험을 계속 진행하였다. 기질과 효소의 비, pH, 반응온도를 변수로 사용하여 중심합성계획에 의해 총 16개의 조건으로 하여 최적화 하였다. 회귀식의 전체 $R^2$는 0.9908이었고, 0.01% 유의수준을 나타내었다. 중심합성계획에 따른 maximum response는 기질 농도 26.32%, pH 6.32, $51.29^{\circ}C$에서 ACE 저해효과 70.67%로 예측되어졌으며, 실제 실험으로 검증한 결과도 이와 유사하게 69.1%로 확인됨으로써, 본 실험을 통해 ACE 저해활성을 나타내는 가수분해물의 생산이 최적화되었다.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.362-368
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• 2001

The effects of water soluble materials in paper mill sludge on cellulase and $\beta$-glucosidase activities were studied while the optimization of enzyme system for hydrolysis of the paper mill sludge for production of glucose was made. Water soluble materials in the paper mill sludge showed stimulatory effect on carboxymethyl cellulose (CMC) activity, inhibitory effect on filter paper (FP) activity, and no effect on avicelase and $\beta$-glucosidase activities. CMC and ${\beta}$-glucosidase activities at 5 and 10, 5 or 10 and 10, and 10 and 10 U/ml were optimal for hydrolysis of 5, 10, and 20% of the paper mill sludge, respectively.

• Applied Biological Chemistry
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• 제38권6호
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• pp.502-506
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• 1995

토양으로부터 갈락토스 전이활성이 우수한 ${\beta}-galactosidase$를 생산하는 미생물을 분리하고 부분동정하여 Bacillus sp. A1으로 명명하였다. 선발된 균주가 생산하는 효소는 40%(W/W) 유당용액에서 초기유당의 70%가 전환되었을 때 90%의 높은 전이율을 보였다. 효소의 생합성은 유당에 의하여 유도되었고 포도당에 의하여 저해받았다. 효소생산을 위한 탄소원으로는 유당이, 유기질소원으로는 효소분해 대두단백질이 적합하였다. 탄소원과 유기질소원을 최적화하므로써 배양된 균주의 효소활성은 최소배지에서 배양된 효소활성과 비교하여 약 3배 이상($0.5\;U/m{\ell}-broth$에서 $1.8\;U/m{\ell}-broth$로) 증가하였다.