• 한국미생물·생명공학회지
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• 제20권4호
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• pp.395-400
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• 1992

토양으로부터 cholesterol oxidase 생산성이 있는 균주를 분리하고, 이들 분리된 균주들로 부터 여러 단계의 균주 선발 실험을 통하여 cholesterol oxidase 생산성이 가장 우수한 미생물을 선별하여 HSL613이 라고 명명하였다. 이 HSL613은 $37^{\circ}C$에서 보다 $30^{\circ}C$에서 배양했을 때 더 높은 효소생산성을 나타내었고 배양시간이 경과함에 따라 pH가 높아지면서 효소생산이 증가하여, 144시간 배양하였을 때 pH는 8.5로 높아졌고 효소생산량도 가장 높았다. 균체량은 120 시간 배양하였을 때 가장 많았다. 본 실험에서 HSL613의 효소생산조건을 검토한 결과 최적 배지조성은 2.0% glucose, 2.0% yeast extract, 0.2% $K_2HP0_4$, 0.1% NaCl. 0.005% $CaCl_22H_2O, 0.001% $FeSO_47H_20$ 로 판명되었으며, $30^{\circ}C$에서 144시간 (6일때) 배양하였을 때 효소생성이 가장 많았고 (10.3U/ml), 종균의 접종량은 1.0%(v/v)일때가 가장 효소생성이 잘 되었다.

• Journal of Microbiology
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• 제42권2호
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• pp.152-155
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• 2004

Pseudomonas sp. K82 has been reported to be an aniline-assimilating soil bacterium. However, this strain can use not only aniline as a sole carbon and energy source, but can also utilize benzoate, p-hydroxybenzoate, and aniline analogues. The strain accomplishes this metabolic diversity by using dif-ferent aerobic pathways. Pseudomonas sp. K82, when cultured in p-hydroxybenzoate, showed extradiol cleavage activity of protocatechuate. In accordance with those findings, our study attempted the puri-fication of protocatechuate 4,5-dioxygenase (PCD 4,5). However the purified PCD 4,5 was found to be very unstable during purification. After Q-sepharose chromatography was performed, the crude enzyme activity was augmented by a factor of approximately 4.7. From the Q-sepharose fraction which exhibited PCD 4,5 activity, two subunits of PCD4,5 (${\alpha}$ subunit and ${\beta}$ subunit) were identified using the N-terminal amino acid sequences of 15 amino acid residues. These subunits were found to have more than 90％ sequence homology with PmdA and PmdB of Comamonas testosteroni. The molecular weight of the native enzyme was estimated to be approximately 54 kDa, suggesting that PCD4,5 exists as a het-erodimer (${\alpha}$$_1$${\beta}$$_1$). PCD 4,5 exhibits stringent substrate specificity for protocatechuate and its optimal activity occurs at pH 9 and 15 $^{\circ}C$. PCR amplification of these two subunits of PCD4,5 revealed that the ${\alpha}$ subunit and ${\beta}$ subunit occurred in tandem. Our results suggest that Pseudomonas sp. K82 induced PCD 4,5 for the purpose of p-hydroxybenzoate degradation.

• 대한임상검사과학회지
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• 제38권2호
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• pp.87-93
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• 2006

This study was done to know a kind and change (transition) of enzymes produceed by Streptomyces halstedii ssp. scabies SA1-27 and Streptomyces violaceusinger C1-6 which showed good lignolytic activity and a good decolorization ratio of remazol brilliant blue R(RBBR) dye. These strains were isolated from soil and identified by the author. The basal medium containg 0.2% glucose was used to measure enzyme activity, Lignin peroxidase 1 (Lip 1) was measured by the methods of Choi, and Bourbonnais and Paice. Lignin peroxidase 2 (Lip 2) was measured by the methods of Ishida et al and Ramachandra et al using 2.4-dichlorophenol(2.4 DCP), manganese peroxidase(Mnp), veratryl alcohol oxidase (VAO), and laccase. They were measured by each of the methods of Choi and Paszczynski et al, and Bourbonnais and Paice, and De Jong et al. In the results, the kind of enzymes produced by Streptomyces halstedii ssp. scabies SA1-27 were Lip 1, Lip 2, VAO, and laccase, and their activities indicated the highest value as each 4.95 nmol/mg protein, $8.45({\times}100^{-3})unit$, 10.25 nmol/mg protein, 9.20 nmol/mg protein on the sixth day of the culture and decreased gradually over time. The kind of enzymes produced by Streptomyces violaceusinger C1-6 were Lip 1, Lip 2, Mnp, VAO, and laccase, and their activities indicated the highest value as each 4.90 nmol/mg protein, $13.85({\times}100^{-3})unit$, 3.10 nmol/mg protein, 11.30 nmol/mg protein, 4.45 nmol/mg protein on the sixth day of the culture and decreased gradually over time. Consequently, the author knew the fact that there were few differences in the kind and quantity of enzymes produced by the two Streptomyces strains, but all enzyme activities indicated the highest value on the sixth day of the culture and decreased gradually over time.

• Geomechanics and Engineering
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• 제17권5호
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• pp.421-427
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• 2019

Coastal erosion is becoming a significant problem in Greece, Bangladesh, and globally. For the prevention and minimization of damage from coastal erosion, combinations of various structures have been used conventionally. However, most of these methods are expensive. Therefore, creating artificial beachrock using local ureolytic bacteria and the MICP (Microbially Induced Carbonate Precipitation) method can be an alternative for coastal erosion protection, as it is a sustainable and eco-friendly biological ground improvement technique. Most research on MICP has been confined to land ureolytic bacteria and limited attention has been paid to coastal ureolytic bacteria for the measurement of urease activity. Subsequently, their various environmental effects have not been investigated. Therefore, for the successful application of MICP to coastal erosion protection, the type of bacteria, bacterial cell concentration, reaction temperature, cell culture duration, carbonate precipitation trend, pH of the media that controls the activity of the urease enzyme, etc., are evaluated. In this study, the effects of temperature, pH, and culture duration, as well as the trend in carbonate precipitation of coastal ureolytic bacteria isolated from two coastal regions in Greece and Bangladesh, were evaluated. The results showed that urease activity of coastal ureolytic bacteria species relies on some environmental parameters that are very important for successful sand solidification. In future, we aim to apply these findings towards the creation of artificial beachrock in combination with a geotextile tube for coastal erosion protection in Mediterranean countries, Bangladesh, and globally, for bio-mediated soil improvement.

• 펄프종이기술
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• 제35권1호
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• pp.34-40
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• 2003

This study was carried out to select the useful bacteria which secret extracellula enzymes for enzymatic deinking agent of old newspaper. CMCase, FPase and xylanase activities of the bacteria liquid culture were measured at optimal growth conditions. Clear zone test was checked on the solid culture. The results of this study were as follow: Eight strains of 28 bacteria isolated from a paper mill soil ground were shown strong CMCase and xylanase activity with the clear zone test. The optimal pH and temperature for culture growth were 6~8 and 26~$34^{\circ}C$, respectively and optimal culture period were less than 60 hours. Based on CMCase, FPase and xylanase activity, strain No. 18, 21, 22 and 28 which were relatively higher than the other strains, were selected for further enzymatic deinking research.

• 한국미생물·생명공학회지
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• 제21권2호
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• pp.119-124
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• 1993

An alkalophilic microorganism for overproduction of cyclodextrin glucanotransferase (CGTase) was newly isolated from hot-water spring soil, and identified as Bacillus firmus var. alkalophilus H609. The strain maintained stability during preservation and cultivation for the enzyme production, and produced significant amount of CGTase corresponding to the volumetric activity of 75 units/mL at 37C, initial pH of 11.2, and after 40 hours. The strain excreted several different proteins showing CGTase activity that catalyzed the formation of mainly beta-and Gamma-type cyclodextrin (ratio of 7:1) from soluble starch without accumulation of alpha-type. Other enzymatic properties were also investigated.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.397-401
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• 1996

A bacterial strain CFCl, which produced an extracellular cycloinulooligosaccharide fructanotransferase(CFTase), was isolated from soil. The isolated strain was identified as a strain of Bacillus sp. The synthesis of CFTase by the bacterium was found to be induced by inulin which was added to the culture medium as a carbon source. The highest activity of CFTase was observed at pH 7.5 and $37^{\circ}C$ in the medium containing 4% inulin and 0.5% peptone as a carbon source and a nitrogen source, respectively. Under the optimal conditions, the enzyme activity in the culture supernatant reached the highest level of 85 munits/ml after 96 h cultivation.

• 미생물학회지
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• 제32권4호
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• pp.297-300
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• 1994

토양에서 분리한 방선균에서 제한효소 활성을 조사하여 그 가운데 Streptomyces diastatochromogenes로부터 제한효소 활성을 확인하였다. 이 균주의 제한효소 SdiI을 균체 15g으로부터 streptomycin sulfate침전, ammonium sulfate 침전, hydroxylapatite colume chromatography, Sephacryl S-200 HR column chromatography, hydroxylapatite column chromatography의 단계를 거쳐 분리하였고, SDS-polyacrylamide gel-electrophoresis에 의하면 소단위체 분자량은 약 35,000Da으로 추정되었다.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.96-104
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• 2019

Beauveria bassiana, one of the most common entomopathogenic fungi, has been isolated, pre defined and characterized in-house from soil of tea cultivation area. Experiments have been performed to verify the presence of chitinase as intracellular metabolite and its release as extracellular product rendering the spores with biopesticide activity. Although there are many responsible enzymes for the pest killer action of B. bassiana, binding property of chitinase depending on presence as well as absence of serine supplemented in the media has been studied with respect to the production and kinetics. A programmed investigation conclusively indicates that the isolated spore (hyphae) of B. bassiana has been metabolically enriched with the enzyme chitinase in presence of an externally added amino acid serine with its inhibitory kinetics.

• 한국식품과학회지
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• 제35권6호
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• pp.1143-1149
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• 2003

본 연구는 Streptococcus mutans를 특이적으로 용균하는 효소를 탐색하고 효소생산 균주의 동정을 수행하였다. 토양으로부터 5,000여주의 알칼리 내성 판주를 선별하였으며 그중 용균활성이 있는 22주를 선별하였으며 가장 용균활성이 높은 균주 1주를 선별하여 Strain No. 4830이라 명명한 후 효소의 생산 조건 및 효소의 특성을 확인한 결과 pH 5에서부터 pH 11에서 안정하였으며 pH 7.0 이상에서 Streptococcus mutans에 대하여 용균활성이 나타났다. 또한 $30^{\circ}C$ 이상에서 효소의 활성을 확인할 수 있었으며 $50^{\circ}C$에서 최대효소활성을 확인하였다. 효소의 열안정성은 $40^{\circ}C$ 이하에서는 안정한 것으로 확인되었다. 균주의 특성을 검토한 결과 균체의 지방산 조성은 중성 조건에서 생장하는 Bacillus계열과는 달리 16-C계열의 지방산함량이 상당히 높은 것을 확인하였으며 Obligate alkalophilic의 특성으로 알려진 branched 15-C 지방산인 $iso-C_{15:0}$와 $anteiso-C_{15:0}$의 함량이 매우 높은 것을 확인할 수 있었다. 또한 생화학적 특성으로 Bacillus 계열로 추정이 가능하였으며 다양한 종류의 당류에 대하여 acid를 형성하지 않은 것으로 확인되어 Strain No. 4830은 Obligate alkalophilic의 특성을 나타내었다. 또한 15% NaCl의 농도에서도 생장하는 것으로 보여 염에 대하여 내성을 갖는 것으로 나타났다. 16S rRNA 분석결과 Bacillus alcalophilus 균주와 94%의 유사성을 나타내었으나 생화학적 및 이화학적인 특성 등에서 Bacillus alcalophilus와 다른 균주로 동정되었다.