• 생명과학회지
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• 제20권5호
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• pp.662-669
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• 2010

폐식용유에서 지방분해효소를 생산하는 세균을 분리하였고, PIBWIN 세균동정 방법으로 생리 생화학적 특성을 조사하여 확인한 결과 Pseudomonas sp. OME로 동정하였다. 여러 기질로 지방분해효소 생산을 조사한 결과 올리브유에서 6.1 U/ml의 생산력을 나타내었다. 물리적 인자인 배양시간, 온도. pH 및 올리브유와 효모 추출액의 영양인자에 의한 지방분해효소 생산 조건을 조사 하였다. 효소의 분비는 배양시간. 올리브유 와 효모 추출액의 농도에 강한 영향을 받았으며, RSM을 이용한 최적화는 이들 인자를 가지고 조사하였다. RSM을 이용한 지방분해효소 생산은 배양시간. 올리브유와 효모 추출액의 농도가 48 hr, 0.3 g, 및 0.9 ml에서 최적 생산조건을 나타냈다.

• 농업과학연구
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• 제14권1호
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• pp.144-155
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• 1987

토양(土壤) 및 하수(下水)에서 단백분해활성(蛋白分解活性)이 약하고 응유활성(凝乳活性)이 강한 SA-101 균주(菌株)를 분리(分離), 선정(選定)하여 Mucor sp. 동정(同定)하였다. 사용균주(使用菌株)에 의한 응유효소생산(凝乳酵素生産)은 밀기울 10 g에 0.1M HCl 을 함유한 수도수 8 ml를 가하여 $30^{\circ}C$에서 60시간의 배양(培養)이 가장 좋았다. Lactose 6%, NaCl 0.05%를 첨가(添加)하였을때 효소생산(酵素生産)이 촉진(促進)되었고 밀기울 g당(當) 9,810 단위(單位)의 효소생산(酵素生産)을 보였다. 유안염석(硫安鹽析)과 동결건조(凍結乾燥)등으로 조제한 조효소제품(粗酵素製品)의 MCA/PA비(比)는 Hansen rennet 보다 낮았으나 Meito rennet과 유사하였고 응유활성(凝乳活性)의 최적온도(最適溫度)는 1/100M $CaC1_2$를 함유한 10% 환원탈지유(還元脫脂乳)를 기질로 하였을 때 $60^{\circ}C$ 부근이었다.

• KSBB Journal
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• 제25권5호
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• pp.453-458
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• 2010

본 연구에서는 효소의 재활용성과 안정성을 확보하기 위해 자석으로 분리가 가능한 polyaniline nanofiber를 개발하였다. 개발된 고정화 효소는 상온에서 8일 동안 90% 이상의 활성도를 보유하였으며 온도가 높은 $55^{\circ}C$에서는 60% 이상의 활성도를 보유하여 안정성의 유지현상을 보였다. 개발된 고정화 효소는 자석으로 분리가 가능하였으며 이 효소를 이용하여 curdlan, agarose, cellulose, 및 미역을 분해한 결과 포도당을 생산하였으며 curdlan을 분해시킨 경우에는 분해 속도가 1.2 g/L/h로 나타나 다른 다당류에 비해 3-10배 이상 빠른 속도를 나타내었다. 고정화 효소를 반복하여 사용하는 경우 10번 반복 사용했을 때 75% 이상의 활성도를 유지하는 것으로 측정되었다. 젖은 미역 줄기를 10 g/L를 분해하기 위하여 5 mg의 고정화 효소를 사용한 결과 24시간 만에 1 g/L의 glucose를 생산하였다.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.416-424
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• 1995

Mechanism of the cyclodextrin (CD) production reaction by cyclodextrin glucanotransferase (CGTase) using swollen extrusion starch as substrate was investigated emphasizing the structural features of starch granule. The degree of gelatinization was identified to be the most representative structural characteristic of swollen starch. The most suitable degree of gelatinization of swollen starch for CD production was around 63.52%. The structural transformation of starch granule during enzyme reaction was also followed by measuring the changes of the degree of gelatinization, microcrystallinity, and accessible and inaccessible portion to CGTase action of residual swollen starch. The adsorption phenomenon of CGTase to swollen starch was also examined under various conditions. The inhibition mechanism of CGTase by various CDs was identified to be competitive, most severely by a-CD. The mechanism elucidated will be used for development of a kinetic model describes CD production reaction in heterogeneous enzyme reaction system utilizing swollen extrusion starch.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권4호
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• pp.244-251
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• 2001

Over half of all biologically active peptide and peptide hormones are $\alpha$-amidated at their C-terminus, which is essential for their full biological activities. Amidation is accomplished through the sequential reaction of the two enzymes encoded by the single bifunctional, peptidyl-glycine $\alpha$-amidating monooxygenase (PAM or an $\alpha$-amidating enzyme). PAM catalyze the forma - tion of a peptide amide from peptide precursors that include a C-terminal glycine, and requires copper molecular oxygen and ascorbate. PAM is the only enzyme that produces peptide amides in vivo. However various strategies utilizing PAM, carboxypeptidase-Y enzymes, and chemical syn-thesis have been developed for producing peptide amides in vitro. The growing need and impor-tance of peptide amide drugs has highlighted the necessity for a efficient in vitro amidating sys-tem for industrial application for the production of peptide hormones, like calcitonin and oxytocin. This review presents the current situation regarding amidation with a special emphasis on the in-dustrial production or peptide hormones.

• 한국미생물·생명공학회지
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• 제27권5호
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• pp.370-377
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• 1999

Thermo-tolerant bacterium producing the xylanase was isolated from soil and identified as Bacillus pumilus. This strain, named Bacillus pumilus TX703, was able to grow ad produce xylanase at the culture temperature of 5$0^{\circ}C$. The maximum xylanase production was obtained when 1%(w/v) birchwood xylan and 1% (w/v) soytone were used as carbon source and nitrogen source, respectively. The biosynthesis of xylanase was under the catabolite repression induced by glucose in the culture medium, and it was completely inhibited in the presence of 0.2% (w/v) glucose. The maximum activity of xylanase was observed from pH8.0 to 9.0 and from 50 to 6$0^{\circ}C$ and the enzyme was highly heat-stable, whose activity remained was over 50% at 8$0^{\circ}C$, and was quite stable from pH5.0 to 10.0.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.187-196
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• 1995

In order to produce fuctional chitooligosaccharides, a strain excreting mainly endo-type chitinase suitable for chitooligosaccharides production was newly screened and identified as Aspergillus fumigatus JC-19. The chitinase excretion was repressed in nutrient rich medium but stimulated by colloidal chitin indicating that the chitinase is inducible type enzyme. Maximum secretion of the enzyme was observed at pH 7.0 and 37$\circ$C . The growth and chitinase production patterns of Aspergillus fumigatus JC-19 showed that the cell growth reached maximum after 4-5 days with final chitinase concentration of 0.46 unit per ml. Excreted chitinase was purified by ammonium sulfate precipitation, colloidal chitin adsorption, anion exchange chromatography, and gel filtration, respectively, and measured M.W of 50 KDa. The enzyme reaction carried out both by crude and purified chitinase showed that the purified chitinase accumulated more chitooligosaccharides of 1-6 degree of polymerization than that of crude chitinase.

• 생명과학회지
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• 제9권1호
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• pp.22-28
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• 1999

A bacterium producing exo-inulinase was isolated from soil and identified Pseudomonas sp. and named as Pseudomonas sp. NO5. The optimal culture conditions for the efficient production of exo-inulinase from Pseudomonas sp. NO5 were obtained by cultivating with the medium 1$\%$ sucrose, 0.5$\%$ yeast extract, 0.5$\%$ $(NH_4)_2$$HPO_4$, 0.05$\%$ $MgSO_4$ㆍ$7H_2$0, 0.001$\%$ and $FeSO_4$ㆍ$7H_2$0 at $37^{\circ}C$ in initial pH 7.0 for 20 hours. The enzyme was induced maximally in the presence of sucrose or inulin at early stationary phase about 20 hour after cultivation.

• Mycobiology
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• 제36권3호
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• pp.167-172
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• 2008

Beef luncheon meat is one of the most popular meals in several countries in the world including Egypt. Thirty one fungal species and 3 species varieties were recovered from 30 samples of beef luncheon meat collected from different supermarkets in Qena. Alternaria, Aspergillus, Emericella, Mucor, Mycosphaerella, Penicillium and Rhizopus were the most common genera on the two types of media. From the above genera, the most prevalent species were Alternaria alternate, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Emericella nidulans, Mucor racemosus, Mycosphaerella tassiana, Penicillium chrysogenum and Rhizopus stolonifer. Screening of fungi for their abilities to produce lipase enzyme showed that, ten isolates represented 32.26% of total isolates appeared high lipase production, while sixteen isolates (51.61%) were moderate and 5 isolates (16.13%) were low producers. Aspergillus niger, Fusarium oxysporum and Nectria haematococca produced the highest amount of lipase enzyme, so these fungi were used in further studies. The incorporation of five food preservatives (Disodium phosphate, sodium benzoate, citric acid, potassium sorbate and sodium citrate) individually in the culture medium of lipase production exhibited an inhibitive effect on the mycelial growth and enzyme production by Aspergillus niger, Fusarium oxysporum and Nectria haematococca.

• 미생물학회지
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• 제14권2호
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• pp.49-49
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• 1976

Enzyme activities, such as glucoamylase dextrinogenic amylase, cellulase, acid protase and neutral protease, of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their enzyme activities are surveyed from taxonomical, ecological and physiological viewpoint. Effect of carbon sources and phytohormones on the amylalse production of Rhizopus are also measured. Among the 735 strains of Phizopus isolated, strain number 587 exhibiting most prominent dextrinogenic amylase and netral protease activity is selected as the best strain, and the strain number 673, 108, 329, 165 and 728 are seleted for their predominant cellulase, acid protease, glucoamylase, dextrinogenic amylase and neutral protease activities, respectively. R.acidus and R.nigricans which exhibited relatively higher callulalse activity, showed lower activities for both amylase. R.tritici exhibited higher protease activity. The relations between activities and various substrates of wild strains are not outstnading difference, although the strains isolated from inland region exhibited more or less higher amylase and cellulase activities, than those of coast region, generally. Lactose and dextrin are most effective carbon sources for glucoamylase and dextrinogenic amylase production of the Rhizopus niveus, respectively. Although all phytohormones tested are effective for production of amylase by the Rhizopus strains, except nicotinamide for glucoamylase production, biotin and ascorbate are most effective for dextrinogenic amylase and glucoamylase production, respectively.