• Journal of Microbiology
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• 제34권4호
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• pp.334-340
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• 1996

The enzyme, cis,cis-muconate lactonizing enzyme has been proposed to play a key role in the $\beta$-ketoadipate pathway of benzoate degradation. A 3.2-kb EcoRI fragment termed as pRSU2, isolated from a Pseudomonas cepacia genomic library was able to complement the catB defective mutant. Several relevant restriction enzyme sites were determined within the cloned fragment. In Pseudomonas putida SUC2 carrying pRSU2, the enzyme activity was relatively higher than those of the induced or partially induced state of wild type P. putida PRS2000. It was probably due to higher expression of P. cepacia catB in P. putida PRS2000. It was probably due to higher expression of P. cepacia catB in P. putida. One possible interpretation of these results is that the catB promoter in P. cepacia is recognized within P. putida, resulting in the almost same expression level.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.69-77
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• 2019

Screening microorganisms that can produce glucan hydrolases for industrial, environmental, and biomedical applications is important. Herein, we describe a novel approach to perform glucan hydrolase screening-based on analysis of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) spectra-which involves degradation of the oligo- and polysaccharides. As a proof-of-concept study, glucan hydrolases that could break down glucans made of several glucose units were used to demonstrate the MALDI-MS-based enzyme assay. First, the enzyme activities of ${\alpha}$-amylase and cellulase on a mixture of glucan oligosaccharides were successfully discriminated, where changes of the MALDI-MS profiles directly reflected the glucan hydrolase activities. Next, we validated that this MALDI-MS-based enzyme assay could be applied to glucan polysaccharides (i.e., pullulan, lichenan, and schizophyllan). Finally, the bacterial glucan hydrolase activities were screened on 96-well plate-based platforms, using cell lysates or samples of secreted enzyme. Our results demonstrated that the MALDI-MS-based enzyme assay system would be useful for investigating bacterial glucoside hydrolases in a high-throughput manner.

• Ocean and Polar Research
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• 제24권1호
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• pp.47-53
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• 2002

To evaluate the effect of reed population on the distribution and activities of microorganisms, vertical distribution of heterotrophic bacteria, degradation rate of cellulose, extracellular aminopeptidase activity (APA) and metabolic diversity based on GN2 Microlog plate were measured at two salt marsh stations in Hogok-ri, Namyang Bay, west coast of Korea. The number of heterotrophic bacteria at station 1 (reed population inhabited area) showed 2 to 6 times higher than that of station 2 (exposed area) with exception in the surface layer. Cellulose degradation rates in station 1 showed more than 50%. month-I and higher than that of station 2 (10.2 to 38.4%. $month^{-1}$). Yet the APA at two stations did not show difference except surface layer and suggested that APA might not be a significant factor in degrading marsh plant debris. Lipid class compounds, cell wall polymers and L-alanine were widely used by microorganisms. The number and activities of bacterial populations especially concerned in plant debris degradation seemed to be stimulated by the reed communities.

• Journal of Microbiology
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• 제43권6호
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• pp.569-571
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• 2005

White-rot fungi have the following enzyme systems for lignin degradation: laccase, lignin peroxidase and manganese peroxidase. There are other types of peroxidases related to lignin degradation, one of which we have cloned a cDNA gene of manganese-repressed peroxidase (MrP) in Trametes versicolor isolated in South Korea. The mrp transcript level has been decreased by $1{\mu}M\;of\;Mn^{2+}$.

• 한국환경과학회지
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• 제13권12호
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• pp.1139-1144
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• 2004

We studied a extraction and degradation of alginate from seaweed-stems using microorganism DS-02. DS-02 has a maximum growth rate at $30^{\circ}C$ and the enzyme has a maximum activity of alginate extraction at $35^{\circ}C.$ The yield of alginate extraction using DS-02 is about $16.0{\%}$ for 3.0 hour and molecular weight of the alginate decreased to about 1/8 of initial value after 24 hour extraction. Alginate extraction method by DS-02, compared with general alkali-extraction method, has an advantage of decreasing the molecular weight of alginate during extraction.

• Preventive Nutrition and Food Science
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• 제7권1호
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• pp.33-36
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• 2002

A catalase from Micrococcus sp. isolated from soil was applied to degrade hydrogen Peroxide in wastewater from a semiconductor industry. The degradation rates of hydrogen peroxide increased with increasing reaction time and catalase concentrations in the reaction mixture. However, in the presence of aluminum chloride or chloride oxide used in detergent compounds, the degradation rate of hydrogen peroxide was not affected. Enzyme stabilizers and antifoam did not affect the degradation rates of hydrogen peroxide.

• Journal of the Korean Wood Science and Technology
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• 제35권6호
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• pp.91-99
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• 2007

소나무, 낙엽송, 리기다소나무, 잣나무 등 국내산 침엽수 목분을 기질로 진탕배양했을 때 갈색부후균인 Fomitopsis palustris로부터 분비된 당 분해성 균체 외 효소는 Endoglucanase (EG), $\beta$-glucosidase (BGL) 및 $\beta$-1,4-xylosidase (BXL)와 함께 결정형 셀룰로오스를 분해하는 Cellobiohydrolase (CBH)도 활성을 갖은 것으로 나타났다. 4주간 배양에서 변재는 심재에 비해 큰 효소활성을 나타냈으나, 배양기간을 증가시킴으로써 효소활성이 커지는 것으로 밝혀져 효소에 의한 목질바이오매스 분해의 경우 심변재 혼합처리도 가능할 수 있음이 시사되었다. 그리고, 균체 의 단백질을 SDS-PAGE로 분석한 결과, 대부분의 수종에서 나타나는 효소의 단백질 패턴은 거의 유사한 것으로 나타나 효소를 이용한 목질계 바이오매스 분해의 경구 수종별 혼합처리도 가능함이 시사되었다. F. palustris에 의해 분해된 목분(60 mesh 통과) 셀룰로오스의 결정화도 감소율은 4주 배양에서 약 4.2~20.4%, 8주 배양에서 약 12.9~28.9% 수준으로 나타났다.

• KSBB Journal
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• 제26권4호
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• pp.300-304
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• 2011

Phytases are hydrolytic enzymes that catalyze the sequential hydrolysis of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate) to myo-inositols with lower numbers of phosphate groups. Two types of phytases have been identified which initiate hydrolysis of the phytic acid at either the 3- or 6- position of the inositol ring. In the present investigation, a mathematical model was proposed and computed to estimate maximum enzyme reaction rate constants which fit the experimental data obtained by other authors. Although the data points were scattered to some extent, good agreement was found between the model and the experiment data. It appears that the maximum rate constants of removal of the first, second, and third phosphate groups were not equal. Also there was neither a steady trend upward or downward in the rate constants with the stepwise hydrolysis reactions.

• Journal of the Korean Wood Science and Technology
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• 제40권2호
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• pp.123-132
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• 2012

Pre-pulping extracts were found to contain a dilute amount of xylo-oligosaccharides and acetic acid as the major components, and many minor components including other organic acids, lignin-derived phenolics, and sugar degradation products. Once separated from the pulp, a secondary hydrolysis step was required to hydrolyze oligomeric hemicellulose sugars into monomeric sugars before fermentation. The following study detailed the extent of hemicellulose recovery by pre-pulping using hot water extraction and characterized the hydrolysis of the extract with respect to comparing acid and enzymatic hydrolysis. The secondaryhydrolysis of hot water extracts made at an H-Factor of 800 was tested for a variety of acid and enzyme loading levels using the sulfuric acid and xylanases. The maximum fermentable sugar yield from acid and enzyme hydrolysis of the extract was 18.7 g/${\ell}$ and 17.7 g/${\ell}$ representing 84.6% and 80.1% of the maximum possible yield, respectively.

• BMB Reports
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• 제30권4호
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• pp.258-261
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• 1997

A simple quantitative assay method for ribonuclease activity has been developed. This method is based on the decrease of fluorescence intensity emitted by the ethidium bromide bound to RNA due to the degradation of RNA by ribonuclease. The substrate RNA was reacted with ribonuclease A and the fluorescence intensity was measured after the addition of ethidium bromide. The intensity difference was calculated using a blank reaction mixture containing no RNase. Whole cellular RNA substrate produced a significant error and was not suitable for this assay method possibly because of local microheterogeniety caused by high molecular weight rRNA. but satisfying results were obtained with tRNA substrate. The intensity difference increased linearly by raising enzyme concentration up to $2{\times}10^{-4}$ Kunitz Units of ribonuclease A. More refined and reliable results were obtained by use of initial reaction velocities which were calculated from the plots of intensity difference vs time. A linear relationship between initial velocities and enzyme concentrations was observed up to 0.01 Kunitz Units of enzyme.