• Journal of Microbiology and Biotechnology
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• 제33권2호
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• pp.195-202
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• 2023

Protease is a widely used enzyme particularly in the detergent industry. In this research, we aimed to isolate alkaline protease-producing bacteria for characterization as a laundry detergent additive. The screening of alkaline protease production was investigated on basal medium agar plus 1% skim milk at pH 11, with incubation at 30℃. The highest alkaline protease-producing bacterium was 6BS15-4 strain, identified as Bacillus gibsonii by 16S rRNA gene sequencing. While the optimum pH was 12.0, the strain was stable at pH range 7.0-12.0 when incubated at 45℃ for 60 min. The alkaline protease produced by B. gibsonii 6BS15-4 using dairy effluent was characterized. The optimum temperature was 60℃ and the enzyme was stable at 55℃ when incubated at pH 11.0 for 60 min. Metal ions K⁺, Mg²⁺, Cu²⁺, Na⁺, and Zn²⁺ exhibited a slightly stimulatory effect on enzyme activity. The enzyme retained over 80% of its activity in the presence of Ca²⁺, Ba²⁺, and Mn²⁺. Thiol reagent and ethylenediaminetetraacetic acid did not inhibit the enzyme activity, whereas phenylmethylsulfonyl fluoride significantly inhibited the protease activity. The alkaline protease from B. gibsonii 6BS15-4 demonstrated efficiency in blood stain removal and could therefore be used as a detergent additive, with potential for various other industrial applications.

• 한국축산식품학회지
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• 제44권3호
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• pp.723-737
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• 2024

Yeast protein can be a nutritionally suitable auxiliary protein source in livestock food. The breakdown of proteins and thereby generating high-quality peptide, typically provides nutritional benefits. Enzyme hydrolysis has been effectively uesed to generate peptides; however, studies on the potential applications of different types of enzymes to produce yeast protein hydrolysates remain limited. This study investigated the effects of endo- (alcalase and neutrase) and exotype (flavourzyme and prozyme 2000P) enzyme treatments on yeast protein. Endotype enzymes facilitate a higher hydrolysis efficiency in yeast proteins than exotype enzymes. The highest degree of hydrolysis was observed for the protein treated with neutrase, which was followed by alcalase, prozyme 2000P, and flavourzyme. Furthermore, endotype enzyme treated proteins exhibited higher solubility than their exotype counterparts. Notably, the more uniform particle size distribution was observed in endotype treated yeast protein. Moreover, compared with the original yeast protein, the enzymatic protein hydrolysates possessed a higher content of β-sheets structures, indicating their higher structural stability. Regardless of enzyme type, enzyme treated protein possessed a higher total free amino acid content including essential amino acids. Therefore, this study provides significant insights into the production of protein hydrolysates as an alternative protein material.

• KSBB Journal
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• 제19권2호
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• pp.93-97
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• 2004

본 연구는 환경 문제점으로 대두되고 있는 슬러지의 효과적인 저감을 위한 방법으로서 효소를 이용하여 슬러지상 유기물의 가용화율을 높여서 소화조 내에서 미생물의 소화효율을 높이기 위한 것이다. 효소에 의한 슬러지의 가수분해 효율을 높이기 위하여 소량의 오존 (0.02 g $O_3$/g SS, 0.03 g $O_3$/g SS)으로 슬러지를 처리한 후 다양한 효소로 슬러지의 가수분해를 유도함으로써 슬러지의 SCOD를 높여 유기물의 가용화를 향상 시켰다. 여러 가지 효소 중 (Protease, $\alpha$-amylase, glucosidase, lipase)에서 protease가 가장 높은 슬러지의 가수분해 효율을 나타내었다. 오존과 효소로 전처리를 실시한 경우 오존 처리만 한 슬러지에 비해 SCOD 증가량이 높게 나타났으며, 단일 효소보다는 복합 효소를 사용했을 때 유기물의 가용화에 더 효과적임을 확인할 수 있었다. 또한, 효소 전처리시, 효소의 최적온도 조건 (50-6$0^{\circ}C$)을 맞추어 주었을 경우가 상온에서 효소 전처리를 실시했던 경우에 비해 SCOD값이 1.5-2배 정도 증가하여, 더 높은 가수분해 효율을 보였다. 반면, 소화반응에 있어서는, 효소 전처리를 실시한 슬러지와 효소 전처리를 실시하지 않고 오존전처리만을 실시한 슬러지의 소화반응을 비교해 본 결과, 효소전처리를 실시한 슬러지의 SCOD 및 TCOD의 감소량이 오존처리만 실시한 슬러지에 비해 높게 나타났으며, 단일효소보다도 복합효소에서 높은 SCOD와 TCOD의 감소량을 나타내었다. 따라서, 슬러지를 효소로 전처리하는 것은 슬러지 저감에 효과적으로 작용할 수 있을 것으로 기대되며, 이러한 슬러지의 효소 전처리 방법은 다양한 다른 슬러지 처리방법과 함께 슬러지 처리효율을 향상시키기 위한 방법으로 유용하게 이용될 수 있으리라 기대된다. 건전한 환경관리를 위한 유역관리기술 개발의 방향 등을 정리하도록 한다.O와 DABA에 반응하는 자외선 조사에 따른 $^1O_2$의 생성은 taurine의 영향을 받지 않았다. GSH와 MPG는 HOCl의 변성 작용을 뚜렷하게 억제하였다. 이상의 결과로 부터 hyaluronic acid의 변성을 포함한 조직 구성성분의 산화성 손상에 있어서 taurine의 보호 작용은 산소 유리 라디칼에 대한 제거 작용과 관계없으며 HOCl과 $NH_2Cl$에 대한 제거 작용 그리고 taurine과 HOCl 또는 $NH_2Cl$의 복합체 형성에 기인할 것으로 시사된다. Taurine의 치올 기가 HOCl과 $NH_2Cl$에 의한 변성에 부분적으로 보호 작용을 나타 낼 것으로 추정된다.경(製麴72時間頃)의 활성(活性)은 보리쌀국(麴), 밀가루국(麴), 찹쌀국(麴), 고구마국(麴)의 순이었다.험 결과 오전용 사료는 관행적인 산란계 배합사료에서 Ca공급제를 제외한 것을 급여하고, 오후용 사료는 Ca공급제를 3배 첨가한 T2처리로 15:00~16:00시에 교체급여를 하면 사료섭취량 감소와 사료비 절감면에서 바람직할 것으로 사료되며, 고에너지-고단백질-저Ca의 분말사료와 저에너지-저단백질-고Ca의 펠렛사료를 혼합급여하면 산란계의 사료섭취 량과 사료비를 절감할 수 있었으며, 오전사료와 오후사료 별도급여의 번거로움을 피할 수 있는 사양체계로 기대가 되나 보다 더 많은 연구가 필요하다.ericin) which has an amino acid composition suitable for many used in cosmetics, textile finishing agents, animal feeding, etc. The degumming process using electrolytic water is available to reduce treatment

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1673-1679
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• 2003

Two hundred forty 1-d-old Arbor Acres broiler chicks were used to investigate the effects of Cu (II)-exchanged montmorillonite (CEM) or montmorillonite on the growth performance, intestinal microflora, bacterial enzyme activities and morphology of broilers. The chicks were assigned randomly into three groups with 80 chicks per treatment. The three dietary treatments were basal diet only (control group), basal diet +1 g $kg^{-1}$ montmorillonite, and basal diet +1 g $kg^{-1}$ CEM. The results showed that the addition of CEM to the diet increased significantly the body weight and feed efficiency, but a similarly significant increase was not found in broilers fed the diet containing montmorillonite. Supplementing the CEM in the diet of broilers also decreased the numbers of Clostridium perfringens and Escherichia coli in the small intestine and cecum. The addition of either CEM or montmorillonite to the diet depressed the activities of $\beta$-glucosidase and $\beta$-glucuronidase in the small intestinal and cecal contents. Data of villus height and crypt depth for duodenum, jejunum and ileum indicated that dietary addition of CEM or montmorillonite improved the small intestinal mucosal morphology.

• BMB Reports
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• 제32권5호
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• pp.486-491
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• 1999

An engineered cDNA from Phanerochaete chrysosporium encoding both the mature and propeptide-sequence regions of lignin peroxidase H2 (Lip H2) was overexpressed in Escherichia coli BL21 (DE3) to evaluate its catalytic characteristics and potential application as a pollution scavenger. All expressed proteins were aggregated in an inactive inclusion body, which might be due to inherent disulfide bonds. Active enzyme was obtained by refolding with glutathione-mediated oxidation in refolding solution containing $Ca^{2+}$, heme, and urea. Propeptide-sequence region was not processed as evidenced by N-terminal sequence analysis. Recombinant Lip H2 (rLip H2) had the same physical properties of the native protein but differed in the $K_{cat}$. Catalytic efficiency ($k_{cat}/K_m$) of rLip H2 was slightly higher than that of the native enzyme. In order to express an active protein, fusion systems with thioredoxin or Dsb A, which have disulfide isomerase activity, were used. The fused proteins expressed by the Dsb A fusion vector were aggregated, whereas half of the thioredoxin fusion proteins were recovered as a soluble form but still catalytically inactive. These results suggest that Lip H2 may not be expressed as an active enzyme in Escherichia coli although the activity can be recovered by in vitro refolding.

• 한국미생물·생명공학회지
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• 제28권1호
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• pp.26-32
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• 2000

Electrostatic forces contribute to the high degree of enzyme transition state complementarity in enzyme catalyzed reaction and such forces are modified by the solvent through its dielectric constant and polar properties. The contributions of electrostatic interaction to the formation of ES complex and the stabilization of transition state of the trypsin catalyzed reaction were probed by kinetic studied with high pressure and solvent dielectric constant. A good correlation has been observed between the increase of catalytic efficiency of trypsin and the decrease of solvent dielectric constant. Activation volume linearly decreased as the dielectric constant of solvent decreased, which means the increase in the reaction rae. Moreover, the decrease of activation volume by lowering the solvent dielectric constant implies a solvent penetration of the active with and a reduction of electrostatic energy for the formation of dipole of the active site oxyanion hole. When the 야electric constant of the solvents was lowered to 4.7 unit, the loss of activation energy and that of free energy of activation were 2.262 KJ/mol and 3.169 KJ/mol, respectively. The results of this study indicate that the high pressure kinetics combined with solvent effects can provide unique information on enzyme reaction mechanisms, and the controlling the solvent dielectric constant can stabilize the transition state of the trypsin-catalyzed reaction.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1161-1168
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• 2009

Ethanol production by the simultaneous saccharification and fermentation (SSF) of low-value rice wine cake (RWC) without cooking was investigated. RWC is the filtered solid waste of fermented rice wine mash and contains 53% raw starch. For the SSF, the RWC slurry was mixed with the raw-starch-digesting enzyme of Rhizopus sp. and yeast, where the yeast strain was selected from 300 strains and identified as Saccharomyces cerevisiae KV25. The highest efficiency (94%) of ethanol production was achieved when the uncooked RWC slurry contained 23.03% starch. The optimal SSF conditions were determined as 1.125 units of the raw-starch-digesting enzyme per gram of RWC, a fermentation temperature of $30^{\circ}C$, slurry pH of 4.5, 36-h-old seeding culture, initial yeast cell number of $2{\times}10^7$ per ml of slurry, 17 mM of urea as the nitrogen additive, 0.25 mM of $Cu^{2+}$ as the metal ion additive, and a fermentation time of 90 h. Under these optimal conditions, the ethanol production resulting from the SSF of the uncooked RWC slurry was improved to 16.8% (v/v) from 15.1% (v/v) of pre-optimization.

• Journal of Nutrition and Health
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• 제31권4호
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• pp.687-696
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• 1998

This study was performed to investigate effects of hesperidin and naringin on linpid peroxide formation and antioxidative enzyme activities in rats. Thiobarbituric acid reactive substance (TBARS) concentrations were measured in plasma and liver. Catalase, superoxide dismutase, and glutathione peroxidase activities were measured in erythrocyte and liver. Forty-nine male Sprague-Dauley rats weighing 275.3$\pm$3.3g were blocked into seven groups according to body weight and were raised fro four weeks on diets containing 0.25, 0.50 or 1.00%(w/w) hesperidin or naringin . Food intake, weight gain , food efficiency ratio, and weights of liver, kidney, spleen ,and epididymal fat pad were not significantly different among groups. In 0.50 and 1.00% naringin groups , plasma TBARS concentrations were significantly decreased with a dose response patter. In 0.25, 0.50 and 1.00% hesperidin groups, liver TBARS concentrations were significantly decreased without a dose dependent patter. Antiosidative enzyme activities in erythrocyte and liver were not significantly affected by type and amountof dietary bioflavonoid, but in the 1.00% hesperidin group, catalase, superoxide dismutase, and glutahione perosidase activities in linver showed a tendency to increase. In conclusion, naringin inhibited lipid peroxide formation with a dose response pattern in plasma without changing the activities of antioxidative enzymes. Hesperidin adminstration, regardless of the level in the diet, inhibited lipid peroxide formation in liver.

• Asian-Australasian Journal of Animal Sciences
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• 제15권4호
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• pp.596-601
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• 2002

The present study was designed to examine the effect of ozone treatment in microencapsulated ${\beta}$-galactosidase on inactivation of the enzyme and sterilization of microorganism. The efficiency was the highest as 78.4% when the ratio of polyglycerol monostearate (PGMS) was 15:1. Activities of lactase remaining outside the capsule were affected by ozone treatment. With the increase of ozone concentration and duration of ozone treatment, the activity reduced significantly. In sensory aspect, with 2% microcapsule addition, no significant difference in sweetness was found compared with a market milk during 12 d storage. Above result indicated that the additional washing process of lactase was not necessary to inactivate the residual enzyme. In a subsequent study, the vegetative cells of microorganisms were completely killed with 10 ppm for 10 min treatment by ozone. The present study provides evidence that ozone treatment can be used as an inactivation and a sterilization process. In addition, these results suggest that acceptable milk products containing lactase microcapsules made by PGMS can be prepared with ozone treatment.

• Asian-Australasian Journal of Animal Sciences
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• 제26권4호
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• pp.552-557
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• 2013

Partially purified ${\alpha}$-galactosidase from Bacillus sp. LX-1 was non-covalently immobilized on a reversibly soluble-insoluble polymer, Eudragit L-100, and an immobilization efficiency of 0.93 was obtained. The optimum pH of the free and immobilized enzyme was 6.5 to 7.0 and 7.0, respectively, while there was no change in optimum temperature between the free and immobilized ${\alpha}$-galactosidase. The immobilized ${\alpha}$-galactosidase was reutilized six times without significant loss in activity. The immobilized enzyme showed good storage stability at $37^{\circ}C$, retaining about 50% of its initial activity even after 18 d at this temperature, while the free enzyme was completely inactivated. The immobilization of ${\alpha}$-galactosidase from Bacillus sp. LX-1 on Eudragit L-100 may be a promising strategy for removal of ${\alpha}$-galacto-oligosaccharides such as raffinose and stachyose from soybean meal and other legume in feed industry.