• 분석과학
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• 제5권4호
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• pp.471-475
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• 1992

유당분해효소를 유지방으로 미세캡슐화시켰으며, 이때의 미세캡슐화 수율을 정량적으로 분석하는 방법을 제시하였다. 본 연구에서 적용한 미세캡슐화 공정과정에 의한 유당분해효소의 불활성화 정도는 초기 효소활성도의 5.2%였으며 이러한 불활성화 정도를 고려하여 유당분해효소의 미세캡슐화 수율을 여러 가지 방법에 의하여 계산하였을 때 각각 92.6% (간접적인 측정방법), 88.6% (열처리에 의한 방법) 및 94.1% (효소처리에 의한 방법)였다.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.144-150
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• 1997

After DNA damage, umuDC is the only SOS operon that must be induced to promote SOS mutagenesis in Escherichia coli. The recombinant plasmid pBC401 and pBC402 were constructed to fuse the lac structural genes with promoter region of umuDC operon to induce the expression of lacZ gene by DNA damage. We transformed the plasmid pBC401 and pBC402 into E. coli MC1061, lacZ deleted strain and determined the activity of $\beta$-galactosidase for various mutagen; UV, mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitroqunoline-1-oxide (NQO), ethyl methanesulfonate (EMS). The $\beta$-galactosidase activities of PBC401 and pBC402 for UV, MMC, and NQO were increased in proportion to expression time until 3 hours thereafter, the activities were constant or slightly decreased. The activities for MNNG and EMS were not so high as for UV, MMC, and NQO. When MNNG and EMS were treated, $\beta$-galactosidase activity of pBC402 was slightly lower than pBC401 but when UV, MMC, and NQO were treated in pBC402, $\beta$-galactosidase activity was slightly higher than in pBC401. Therefore, the pBC402 was better than the pBC401 in terms of sensitivity for frameshift mutagen. We suggest that the plasmid pBC401 and pBC402 are easy to detect mutagens which cause frameshift mutation rather than point mutation.

• 한국식품위생안전성학회지
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• 제2권2호
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• pp.67-73
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• 1987

Kluyveromyces fragilis로부터 $\beta$-galactosidase의 생성조건과 조효소액의 성질 그리고 당 전이 반응에 의한 oligosaccharide 생성을 조사한 결과 다음과 같은 결과를 얻었다. \circled1 Peptone-Yeast extract 배지에 6% lactose를 첨가하였을 때 최대 효소생산을 보였다. \circled2 0.05 M potassium phosphate buffer (pH 7.0)에서 3% toluene를 첨가하여 37$^{\circ}C$ 5시간 배양하였을 때 K. fragilis로부터 효소가 최대로 추출되었다. \circled3 효소의 최적온도는 4$0^{\circ}C$이고 4$0^{\circ}C$ 이상의 열처리에서는 효소가 파괴되었으며, pH6-7에서는 상당히 안정하였다. \circled4 ONPG 기질로 사용하였을 때 Km 값은 2.5mM이었다. \circled5 당 전이 반응의 결과, 7개의 oligosaccharide가 생성되었다. 이상의 실험결과로 볼 때, 본 실험에 사용한 K. fragilis SKD 7001은 Beta-galactosidase의 생산을 위해서 이용 가치가 인정되었으며, 특히, 이 효소의 활성이 중성 pH에서 강하고 안정한 상태를 보이는 것은 시유나 원료우유의 lactose를 중성에서 해야 한다는 점을 고려할 때, 실용적 가치가 있다고 본다. 또, 이 효소의 작용과정에서 생성되는 oligosacchride는 장내 bifidus균의 생육을 촉진시키는 효과가 인정되고 있기 때문에 이용가치를 더욱 높여주는 것으로 생각된다.

• KSBB Journal
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• 제9권4호
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• pp.400-405
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• 1994

호말칼리성이며 고온성인 Bacillus sp. TA-11로 부터 $\beta$galactosidase를 대량생산할 목적으로 배지 조성, 배지의 초기 pH 빛 배양온도와 각종 배양방법 등이 효소생산에 미치는 영향을 검토하였다. ${\beta}$-galactosidase의 최척생산조건은 1.5% lactose, 0.6% y yeast extract, 0.15% $K_2HP0_4$ 초기 pH 9.5, 배양 온도 $50^{\circ}C$이였고 플라스크배양에서는 48시간에 약 4 4350U/ml, 회분배양에서는 36시간에 4200 4400U/ml의 효소가 생산되였다. 또한 유가배양에서 는 120시간에 5200U/ml, 연속배양에셔는 34시간에 4000U/ml의 효소가 생산되었으며 효소의 비활성은 연속배양시 약 3077U/mg으로 제일 좋았다.

• 한국식품저장유통학회지
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• 제2권1호
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• pp.173-183
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• 1995

This paper was carried out to investigate changes in chromatograms of polysacctatides and soluble pectins on Sephadex G-50 and non-cellulosic neutral sugars of polysaccharides isolated from cell wall of persimmon fruits treated with polygalacturonase and $\beta$-galactosidase in vitro. The chromatogram pattern of soluble pectins extracted from cell wall treated with $\beta$-galactosidase on Sephacryl S-500 column were similar to those of untreatment, but contents of soluble pectins treated with $\beta$-galactosidase were different from those of untreatment. The patterns of chromatograms In soluble pectins extracted from cell wall treated with polygalacturonase were more complex and lower molecular polymer than those of other cell wall-degrading enzyme treatments. Non-cellulosic neutral sugar of polysaccharides in fraction I of soluble material treated with polygalacturonase was rhamnose, those in fraction II were similar to those in fraction III and contents of arabinose, xylose and glucose were higher than contents of other non-cellulosic neutral sugars. Non-cellulosic neutral sugars of polysaccharides in fraction I in soluble material by $\beta$-galactosidase treatment were rhamnose, arabinose, galactose and mannose. Content of glucose of polysaccharides in fraction II was higher than that in fraction I . Non-cellulosic neutral sugars treated with mixed enzyme were rhamnose, fucose, arabinose, xylose, mannose, galactose and glucose. Compositions of non-cellulosic neutral sugars of polysaccharides in fraction I were similar to those in fraction II and III.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 춘계학술대회
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• pp.113.2-114
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• 1979

$\beta-Galactosidase$ is an enzyme which catalizes hydrolysis of lactose, a natural substrate, to glucose and galctose and transferring some monosac-charide units to active acceptors as sugar or alcohol. The occurence of $\beta-Galactosidase$ is known in various microorganisms, animals and higher plants and has been studied by many investigatigators. Especially, a great deal of articles for the enzyme of E. coli have been presented in genetic control mechanism and induction-repression effects of proteins, On the other hand, in the dairly products industry, it is important to hydrolyes lactosd which is the principal sugar of milk and milk products. During the last few years, the interest in enzymatic hydrolysis of milk lactose has teen increased, because of the lactose intolerence in large groups of the population. Microbial $\beta-Galactosidases$ are considered potentially most suitable for processing milk to hydrolyse lactose and, in recent years, the immobilized enzyme from yeast has been examined. Howev, most of the microbial $\beta-Gal$ actosidase are intracellular enzymes, except a few fungal $\beta-Gala-$ ctosidases, and extracellular $\beta-Galactosidase$ which may be favorable to industrial applieation is not so well investigated. On this studies, a mold producing a potent extracellular $\beta-Galactosidase$ was isolated from soil and identified as an imperfect fungus, Beauveria bassians. In this strain, both extracellular and intracellular $\beta-Galactosidases$ were produced simultaneously and a great increase of the extracellular production was acheved by improving the cultural conditions. The extracellular enzyme was purified more than 1, 000 times by procedures including Phosphocellulose and Sephadex G-200 chromatographies. Several characteristics of the enzymewas clarified with this preparation. The enzyme has a main subunit of molecular weight of 80, 000 which makes an active aggregate. And at neutral pH range, it has optimum pH for activity and stability. The Km value was determined to be 0.45$\times$10$^{-3}$ M for $o-Nitrophenyl-\beta-Galactoside.$ In any event, it is interesting to sttudy the $\beta-Galactosidase$ of B. bassiana for the mechanism of secretion and conformational structure of enzyme.

• 한국미생물·생명공학회지
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• 제9권4호
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• pp.213-218
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• 1981

순수분리정제된 $\beta$-galactosidase의 분자량은 Sephadex G-200 gel filtration법에서 130,000이며 SDS-polyacrylamide gel electrophoresis에서 130,000외에 70,000이 확인되어 이 효소는 70,000인 2개의 subunit로 구성되어 있다고 판단되었다. 효소의 안정pH는 4.5~7.0이며 효소활성의 최적 pH는 4.7 최적온도는 5$0^{\circ}C$였다. 효소활성 및 안정제로 1가, 2가 금속ion을 필요로 하지않았으며 C $u^{++}$ 1mM에서 59%, galactose 100mM에서 48% 저해되었다. 5% lactose용액, 시유 및 10% skim milk 용액에 이 정제된 $\beta$-galactosidase 10units/$m\ell$를 사용하여 5$0^{\circ}C$에서 4시간 동안 반응시켰을 때 lactose가 각각 69.5%. 88.7% 및 72.6%가 glucose와galactose로 전환된 결과를 얻었다.

• Journal of Microbiology and Biotechnology
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• 제4권3호
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• pp.200-203
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• 1994

Spodoptera frugiperda IPLB-SF-21-AE cells were cultivated in a spin-filter bioreactor with continuous perfusion for the recombinant $\beta$-galactosidase production. At the perfusion rate of 0.06 $hr^{-1}$, the maximum cell density of insect cells in this bioreactor system reached 3.5$\times$$l0^6$ viable cells/ml using the Grace media containing 5% FBS and 0.3% Pluronic F-68. The recombinant $\beta$-galactosidase production of 8, 100 units per reactor volume was also achieved at this perfusion rate.

• KSBB Journal
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• 제15권1호
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• pp.84-87
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• 2000

포항 선형 가속기로부터 얻은 ultrasoft X-선이 대장균의 돌연변이 유도와 plasmid DNA 변이에 주는 영향을 알아보았다. 빔을 조사함에 따라 supercoil 형태의 plasmid DNA가 relaxed 형태로 변하고, 그후 선형으로 변해 감을 확인하였다. 빔을 조사한 plasmid DNA를 E. coli에 형질전환하여 $\beta$-galactosidase의 돌연변이 균을 분리하였고, 빔을 직접 조한 E. coli균으로부터도 $\beta$-galactosidase의 돌연변이 균을 얻었다. 변이된 plasmid DNA와 변이 대장균들의 plasmid DNA의 염기 부분을 변화를 확인하였으며 이 빔에 의해 주로 변이가 일어나는 부분이 있음을 알았다.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 제34차 추계 국제 학술대회
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• pp.384-387
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• 2004

겨울철 토양에서 ${\beta}-Galactosidase$를 생산하는 균주를 분리하였으며 동정한 결과 그람 음성 간균이고 Pantoea spp. 로 확인되었다. Pantoea spp. 균주의 세포 추출물로부터 DEAE-Sephacel chromatography와 affinity chromatography를 이용하여 ${\beta}-Galactosidase$를 분리하였다. Pantoea spp. 의 ${\beta}-Galactosidase$의 반응 최적 온도는 $45^{\circ}C$이이고 최적 pH는 $5.5{\sim}7.5$이고 열안정성을 조사한 결과 $45^{\circ}C$이상의 온도에서 불활성 되는 것으로 나타났고 E. coli에서 분리된 효소보다 저온에서의 활력이 좋았지만 상업적인 효소인 Kluyveromyces lactis (Validase) 보다는 낮았다.