• 동아시아식생활학회지
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• 제16권6호
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• pp.702-706
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• 2006

The aim of this study was to identify the onuses of abnormal precipitation in buckwheat extracts and to suggest the preventive solutions. Abnormal precipitation was formed by the coagulations of small round droplets, and increased when poor quality or old buckwheat used. It was found that, unlike poor quality buckwheat, extracts made from fresh buckwheat showed almost no saccharifying enzyme activity and a lower number of microorganisms. The addition of branched starch to the extracts restricted the occurrence of abnormal precipitation and microorganisms and imparted stability to the extracts.

• 한국지반공학회논문집
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• 제39권8호
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• pp.7-16
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• 2023

본 연구는 매립지 침출수 내 황산염 농도를 저감하기 위해 친환경 지반개량 공법인 Enzyme Induced Carbonate Precipitation(EICP) 공법을 활용하였다. 황산염의 화학적 침전을 유도하기 위해 충분한 탄산칼슘을 생성함과 동시에 여분의 칼슘 이온을 남길 수 있는 최적의 EICP 혼합비가 계산되었다. 최적 혼합비로 처리된 사질토 시편에서 황산염 침전이 전단 강성도에 미치는 영향을 확인하고자 전단파 속도를 측정하였고 전단파 속도 측정은 EICP 반응 및 황산염 반응 시간동안 수행되었다. 실험 결과, 생성된 침전물에 따른 전단 강성도의 발달을 확인하였고 주사전자현미경(SEM)으로 침전물의 유형 및 패턴을 시각적으로 관찰하였다. 고순도 우레아제의 대체제로서 백태가루를 효소로 사용한 EICP 용액의 경우 고순도 EICP 용액과 동일한 탄산칼슘 생성 효율에서 보다 낮은 황산염 제거 효율을 보였는데 이는 백태가루에 포함된 불순물이 석고의 침전을 방해하기 때문이다.

• 환경위생공학
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• 제5권1호
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• pp.49-64
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• 1990

Glucoamylase from the culture filtrate of Aspergillus nicer was purified by ammonium sulfate precipitation, aceton precipitation, DEAE-cellulose ion exchange chromatography and Sephadex G-50 gel fillration. Glucoamylase was secreted into the medium upon growth on glucose, sucrose or a variety of other hexose sugars or hexose sugar polymers and little or no glucoamylase activity was found when glycerol or xylose was used as the carbon source. The optimum pH and temperature (or the maximum enzyme activity were found to be 5.0 and $50^{\circ}C$, respectively. The enzyme was considerably thermostable, for no loss of activity was observed when the enzyme was preincubated at $60^{\circ}C$ for 30 min. The enzyme activity was inhibited by 20 mM of $Hg^{2+}$, $Fe^{2+}$. The km value for starch was 0.045%.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1031-1035
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• 2007

Prostate specific $antigen-{\alpha}_1-antichymotrypsin$ was detected by a double-enhancement strategy involving the exploitation of both colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation. The AuNPs were synthesized and conjugated with horse-radish peroxidase-PSA polyclonal antibody by physisorption. Using the protein-colloid for SPR-based detection of the PSPJACT complex showed their enhancement as being consistent with other previous studies with regard to AuNPs enhancement, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the signal. The limit of detection was found at as low as 0.027 ng/ml of the PSA/ACT complex (or 300 fM), which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

• 미생물학회지
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• 제26권1호
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• pp.52-59
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• 1988

A partially purified preparation of L-galactonolactone oxidase which catalyzes the last step of L-ascorbic acid biosynthesis was obtained from Saccharomyces cerevisiae ATCc 26787. The purification procedures included Triton X-100 treatment, protamine sulfate precipitation, ammonium sulfate precipitation, DEAE-Sepharose CL-6B ion exchange chromatography, Sephadex G-150 gel filtration chromatography, and Phenyl-Sepharose CL-4B hydrophobic interaction chromatography. The optimum temperature for the enzyme activity was about $34^{\circ}C$ and the optimum pH was 6.8-7.0. The substrate specificity was confined to L-aldonolactones, L-galactono-1,4-lactone and L-gulono-1,4-lactone. An apparent Km value of 0.294mM with L-galactono-1,4-lactone as a substrate was found. By comparing the substrate specificities of this enzyme with those of isofunctional enzymes of higher plants and animals, it becomes evident that the enzyme of S. cerevisiae ATCC 26787 is rather similar to the L-gulonolactone oxidase of animals than the galactonolactone dehydrogenase of higher plants.

• Journal of Ecology and Environment
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• 제33권3호
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• pp.223-228
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• 2010

Soil microbes perform crucial roles in the nutrient cycles of forest ecosystems, by effecting the decomposition of organic matter. Enzyme activities have been used to evaluate decomposition rates, as well as microbial activities. The principal objectives of this study were to determine the activities of different soil enzymes, to compare enzyme activities at different elevations, and to elucidate the most important controlling variables for enzyme activities. We conducted a field survey at three sites in Mt. Jumbong on a monthly basis from May, 2004 to September, 2005. Enzyme activities did not change substantially over different seasons. However, the spatial differences were distinct; the lowest elevation site evidenced the lowest levels of enzyme activity. Soils at the lowest elevation were nutrient-depleted soils, and enzyme activities appeared to be affected by precipitation and temperature. However, enzyme activities in fertile soils at high elevations were associated with nutrients and organic matter. The enzyme activities detected in this study differed significantly at the three elevations, and their controlling variables also evidenced different factors.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.863-867
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• 2004

$\alpha$-Galactosidase from A. oryzae DR-5 was induced in the presence of melibiose, raffinose, galactose, and locust bean galactomannan. The enzyme was purified to homogeneity by precipitation with acetone followed by ion-exchange chromatography using DEAE-Sephacel. The purified enzyme showed a single band in both nondenaturing-PAGE and SDS-PAGE. The enzyme was a glycoprotein in nature by activity staining. The molecular weight of the purified enzyme was 93-95 kDa by SDS-PAGE. The enzyme exhibited the optimum pH and temperature at 4.7 and $60^\circ{C}$, respectively. $\alpha$-Galactosidase activity was strongly inhibited by $Ag^{2+}, Hg^{2+}, Cu^{2+}$, and galactose. EDTA, 1,10-phenanthraline, and PMSF did not inhibit the enzyme activity, whereas N-bromosuccinimide completely inhibited enzyme activity. Investigation by TLC showed complete hydrolysis of stachyose and raffinose in soymilk in 3 h at pH 5.0 and $50^\circ{C}$.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.51-55
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• 1997

To utilize the alkaline protease produced by Halomonas sp. ES-10 as an enzyme detergent, the crude enzyme was obtained by methanol precipitation and lyophilization. And it was processed to coated enzyme.The best mixing ratio of components such as coated enzyme, builders, actives, fillers and adjuvants on detergency was examined, and temperature and pH influencing detergency were also tested. Detergency test 0.15% detergent solution was carried out on EMPA test cloth #116 with shaking(90 rpm) for 10 min after 30 min of pretreatment. The detergent which contained coated-enzyme 1%, Zeolite 4A 20%, Tween 80 1. 5%, sodium borate 30%, sodium meta silicate 7.5% and water 40% showed about 90% of washing efficiency at 40$\circ $C and pH 10.0.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.407-413
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• 1996

A novel type of extracellular phospholipase $A_1$ was isolated from Serratia sp. MK1 and purified to homogeneity by ammonium sulfate precipitation, anion exchange and gel filtration chromatography. The purified enzyme was a monomer with a molecular mass of about 43, 000 Da. This enzyme showed the highest lipolytic activity toward phosphatidylserine among the phosphoglycerides tested, and preferentially catalyzed the hydrolysis of the ester bond in phosphatidic acid to lyso-phosphatidic acid. Enzyme activity was completely inhibited by the addition of a chelating agent such as EDTA, and inhibited enzyme activity was fully recovered by the presence of $Ca^{2+}$. This implies that the enzyme requires $Ca^{2+}$ for activity. The enzyme was stable up to $70^{\circ}C$ when incubated for 1 h at pH 8.5, and the optimal pH and temperature were 8.5 and $50^{\circ}C$, respectively.

• 펄프종이기술
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• 제35권3호
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• pp.66-73
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• 2003

Alkaline cellulolytic enzymes are prepared from Coprinus cinereus 2249. Recovery method of enzyme protein from cultured medium and effect factors on enzyme activity of protein were investigated. The results could summarized as follows, \circled1 Amount of enzyme protein from cultured medium was highest in incubation with shaking and addition of skim milk. \circled2 Protein from cultured medium was alkaline enzymatic protein which shows the highest activity at pH 9.0. \circled3 The most effective recovery method of enzyme protein was the precipitation of protein by addition of cultured medium of protein in ethanol. \circled4 The enzyme activity was enhanced by tween-80 and decreased with $Al_2(SO_4)_3$, $H_2O_2$et al, and was little changed with metal ions except $Hg^{++}$.