• 한국환경과학회지
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• 제19권9호
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• pp.1161-1167
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• 2010

The effects of addition of non degradable polymers, polystyrene (PS) and poly(methyl methacrylate) (PMMA) on the rate of enzymatic degradation of biodegradable poly(l-lactide) (PLLA) have been studied in term of surface structure. Since a component in multicomponent polymeric system has shown surface enrichment, PS and PMMA which have lower surface energy than PLLA were selected as a minor blend component (5 wt%). Enzymatic degradation was carried out at $37^{\circ}C$ and pH 8.5 in the aqueous solution of Proteinase K. Two blend systems, partially miscible (PS/PLLA) and immiscible (PMMA/PLLA), showed the surface enrichment of 4 and 2 times of PS and PMMA, respectively. From the weight loss profile data, the slow degradation rate of both blend films was observed. This indicates that PS or PMMA domains which exist at surface act as a retardant of enzymatic attack.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.329-332
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• 2001

It has been known that, in enzymatic synthesis of cephalexin, the conversion yield was reduced by high loading of ampicillin acylase. In order to elucidate this phenomena, pH-controlled synthesis of cephalexin was examined using a purified Acetobacter turbidans acylase. When the pH of the reaction mixture was maintained at $6.20{\pm}0.04$, the reduction of the maximal conversion rate was not observed even with high enzyme loading. The kinetic parameters also suggest that pH drop during the enzymatic synthesis of cephalexin was mainly attributed to the rapid hydrolysis of D-${\alpha}$-phenylglycine methyl ester to D-${\alpha}$-phenylglycine, rather than the disappearance of 7-amino-3-deacetoxycephalosporanic acid for cephalexin synthesis. At higher molar ratio of two substrates, [D-${\alpha}$-phenylglycine methyl ester]/[7-amino-3-deacetoxycephalosporanic acid], the conversion rate was also elevated under pH-controlled enzymatic synthesis, which implies that the main reason for the pH drop is due to the production of D-${\alpha}$-phenylglycine methyl easter, the effect of a water-methanol cosolvent system on the ester, the effect of a water-methanol cosolvent system on the conversion profile was also examined. Even the though the conversion rate was increased in 10% methanol solution, a higher than 16% methanol in the reaction mixture caused an inactivation of enzyme.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.154-165
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• 2021

This study aimed to investigate whether the antidiabetic drugs dipeptidyl peptidase 4 (DPP4) inhibitors such as evogliptin and sitagliptin affect the membrane DPP4 (mDPP4) enzymatic activity and immune function of T helper1 (Th1) cells in terms of cytokine expression and cell profiles. The mDPP4 enzymatic activity, cytokine expression, and cell profiles, including cell counts, cell viability, DNA synthesis, and apoptosis, were measured in pokeweed mitogen (PWM)-activated CD4+CD26+ H9 Th1 cells with or without the DPP4 inhibitors, evogliptin and sitagliptin. PWM treatment alone strongly stimulated the expression of mDPP4 and cytokines such as interleukin (IL)-2, IL-10, tumor necrosis factor-alpha, interferon-gamma, IL-13, and granulocyte-macrophage colony stimulating factor in the CD4+CD26+ H9 Th1 cells. Evogliptin or sitagliptin treatment potently inhibited mDPP4 activity in a dose-dependent manner but did not affect either the cytokine profile or cell viability in PWM-activated CD4+CD26+ H9 Th1 cells. These results suggest that, following immune stimulation, Th1 cell signaling pathways for cytokine expression function normally after treatment with evogliptin or sitagliptin, which efficiently inhibit mDPP4 enzymatic activity in Th1 cells.

• International Journal of Internet, Broadcasting and Communication
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• 제11권4호
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• pp.1-10
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• 2019

This Dietary cholesterol augments lipid profile and primes production and activation of platelets, leading to development of atherosclerosis which produce several detrimental effects on cardiovascular health. Ethnomedicine and Mediterranean diet are natural sources and cost effective modes against several ailments including cardiovascular diseases while fermented foods have gained interest due to their increased nutrient profile, enhanced bioavailability and efficacy. Garlic has been known to reduce cholesterol and inhibit platelet activation. We examined whether fermented garlic ameliorates effects of hypercholesterolemia and platelet functions in rats. Methodology: Male SD rats were fed with hypercholesterolemia diet and treated with spirulina, fermented and non-fermented preparations of garlic for one month. Platelet aggregation and granule secretion were assessed to evaluate platelet activation. Liver and kidney weights, lipid and enzymatic profile of serum and whole blood analysis was performed. Expressions of SREBP, ACAT-2 and HMG-CoA were assessed using RT-PCR while liver and adipose tissues were analyzed for histological changes. Both fermented and non-fermented garlic inhibited platelet aggregation and granule secretion while fermented garlic showed greater inhibitor tendency. Fermented garlic significantly reduced liver weight and triglycerides concentrations than non-fermented garlic. Similarly, fermented garlic greatly abrogated the detrimental effects of steatosis on liver and adipose tissues. Fermented garlic significantly improved lipid profile and modulated platelet functions, thereby inhibiting atherosclerosis and platelet related cardiovascular disorders.

• 미생물학회지
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• 제42권4호
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• pp.257-264
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• 2006

한국의 임상검체와 자연환경에서 분리된 Cryptococcus neoformans 58주에 대한 혈청형과 세포외효소 생성능에 관한 셍물학적 특성을 조사하였다. 환자로부터 분리된 임상균주 51주 중 48주는 혈청형 A (94.1%) 였으며 2주는 혈청형 B (3.92%),그리고 나머지 1주는 혈청형 D (1.96%)였다. 자연환경에서 분리된 7주는 비둘기 분변에서 분리된 것들이며 모두 혈정형 A였다. 모든 균주는 proteinase와 phnospholipase를 생성하였고, 또한 API-ZYM system을 이용한 19종류의 효소생성능 시험에서는 alkaline phosphatase, esterase (C4), esterase lipase (C8), leucine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase, $\alpha$-glucosidase, 그리고 $\beta$-glucosidase를 생성하였으나, N-acetyl-$\beta$-glucosarninidase는 39주 (67.2%)에서만 생성하였다. 혈청형 B로 동정된 2주와 혈청형 A로 동정된 균주중 1주는$\beta$-glucuronidase를 생성하였다. 본 연구에 사용된 총21종류의 효소 생성능 시험을 기초로 하여 생물형을 구분하였는데, 모두 4가지의 유형을 나타내었고, 또한 임상과 환경균주에서 혈정형과 생물형 특성간의 유의한 상관성를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.654-662
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• 2024

To investigate the effect of the predominant fungal species from Korean traditional meju and doenjang on soybean fermentation, the enzymatic activity and amino acid production of twenty-two fungal strains were assessed through solid- and liquid-state soybean fermentation. Enzymatic activity analyses of solid-state fermented soybeans revealed different enzyme activities involving protease, leucine aminopeptidase (LAP), carboxypeptidase (CaP), glutaminase, γ-glutamyl transferase (GGT), and amylase, depending on the fungal species. These enzymatic activities significantly affected the amino acid profile throughout liquid-state fermentation. Strains belonging to Mucoromycota, including Lichtheimia, Mucor, Rhizomucor, and Rhizopus, produced smaller amounts of total amino acids and umami-producing amino acids, such as glutamic acid and aspartic acid, than strains belonging to Aspergillus subgenus circumdati. The genera Penicillium and Scopulariopsis produced large amounts of total amino acids and glutamic acid, suggesting that these genera play an essential role in producing umami and kokumi tastes in fermented soybean products. Strains belonging to Aspergillus subgenus circumdati, including A. oryzae, showed the highest amino acid content, including glutamic acid, suggesting the potential benefits of A. oryzae as a starter for soybean fermentation. This study showed the potential of traditional meju strains as starters for soybean fermentation. However, further analysis of processes such as the production of G-peptide for kokumi taste and volatile compounds for flavor and safety is needed.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 추계학술대회 심포지움
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• pp.243.3-244
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• 1979

Low molecular weight endo-glucanase fraction of cellulase from Trichoderma reesei was purified using Sephadex G-100 and concanavalin A-Sepha-rose 4B affinity chromatography. Its biochemical characteristics including pH profile, temperature profile and kinetic behavior were studied. The optimum conditions for enzymatic reaction were pH 6.0 and $5^{\circ}C.$ The activation energy for CMC (carboxymethylcellulose) was 10,800 cal/mole. Its adsorption to amorhous and crystalline cellulose was observed. Adsorption to amorphous cellulose was more rapid and greater than that of crystalline cellulose. Reconstitution study was performed. Significance of low molecular weight endo-glucanase on cellulose hydrolysis will be further discussed.

• 한국수산과학회지
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• 제55권6호
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• pp.808-816
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• 2022

This study was conducted with a view toward enhancing the industrial utilization of a male sailfin sandfish Arctoscopus japonicus based on its application in the preparation of Sik-hae, a Korean traditional fermented fishery product prepared using hard-boiled rice and enzymatic malt sprouts. As an alternative to rice and malt sprouts, we evaluated the utility of rice Koji for Sik-hae fermentation by investigating the physicochemical changes that occur during fermentation. The sailfin sand fish Sik-hae fermented with 10% or 20% rice Koji was found to show similar fermentation characteristics to the control fermentation with 20% hard-boiled rice and 4% malt sprouts, with respect to acid production, texture profile, and the softening of bones during the entire fermentation period. In particular, compared with the control, the addition of 10% rice Koji reduced the dehydration of Sik-hae and increased the content of free amino acids, which contributed to preventing a marked reduction in pH during fermentation. Accordingly, 10% rice Koji is proposed as a viable alternative enzymatic agent for the preparation of Sik-hae, which can contribute enhancing the desired properties of this traditional food product.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6295-6298
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• 2012

Oxidant/antioxidant balance has been suggested as an important factor for initiation and progression of cancer. The objective of this study was to determine changes in the levels of malondialdehyde (MDA), nitric oxide (NO), total cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, total antioxidant capacity (TAC), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities in serum samples of breast cancer patients (n=30) and healthy subjects (n=100). MDA and NO levels were found to be increased in breast cancer patients compared to the healthy subject group (p<0.05). Total cholesterol and triglycerides were elevated; and HDL-cholesterol level was found to be decreased in the cancer patients as compared to the healthy subjects (p<0.05). Compared to the healthy group, both serum TAC levels (p<0.001) and activity of SOD and GSH-Px (p=0.05) were found to be decreased in the breast cancer patients as compared to the healthy controls. Considering the data presented in this study, we suggest that free radicals induce lipid eroxidation and peroxidation of unsaturated fatty acid with decreased activity of enzymatic antioxidants in breast cancer.

• 한국미생물·생명공학회지
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• 제23권5호
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• pp.559-564
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• 1995

Twenty microbial strains producing the acylase were isolated from soil by using Micrococcus luteus ATCC 9341 as an indicator strain, using either D-($\alpha $)-phenylglycine methylester and 7-aminocephalosporanic acid (7-ACA) or glutaric acid dimethylester and 7-ACA as substrates. Among the isolates, only one strain was turned out to be the 7-ACA producer from either cephalosporin C or glutaryl 7-ACA as the substrates by using the overlay of 7-ACA sensitive strain (SS5). 7-ACA produced from cephalosporin C by an isolate (APS20) was detected by high performance liquid chromatography. The isolated strain (APS20) was identified to Bacillus macerans on the basis of cellular fatty acid profile by gas chromatography. Bacillus macerans APS20 had no $\beta $-lacta-mase activity on cephalosporin C, and that is very important for the enzymatic production process of 7-ACA. However, this strain was resistant up to 100 $\mu $g/ml of cephalosporin C.