• Journal of Microbiology and Biotechnology
• /
• 제18권4호
• /
• pp.695-703
• /
• 2008

A locally isolated thermophile, Geobacillus sp. SAB-40, producing thermostable extracellular amylase constitutively and an induced intracellular ${\beta}$-galactosidase was characterized and identified based on 16S rRNA sequencing. A phylogenetic analysis then revealed its closeness to Geobacillus stearothermophilus. To evaluate the effect of the culture conditions on the coproduction of both enzymes by G stearothermophilus SAB-40, a Plackett-Burman fractional factorial design was applied to determine the impact of twenty variables. Among the tested variables, $CaCI_2$, the incubation time, $MgSO_4{\cdot}7H_2O$, and tryptone were found to be the most significant for encouraging amylase production. Lactose was found to promote ${\beta}$-galactosidase production, whereas starch had a significantly negative effect on lactase production. Based on a statistical analysis, a preoptimized medium attained the maximum production of amylase and ${\beta}$-galactosidase at 23.29 U/ml/ min and 12,958 U/mg biomass, respectively, which was 3-and 2-fold higher than the yield of amylase and lactase obtained with the basal medium, respectively.

• 한국식품영양과학회지
• /
• 제15권4호
• /
• pp.32-39
• /
• 1986

토양에서 분리한 여러가지 곰팡이류 가운데 beta-galactosidase 생성력이 가장 좋은 Aspergillus niger CAD 1을 효소 생산 균주로 선정 하였다. 이 균주의 효소 생산 최적 배양조건은 밀기울에 0.5% 탈지 분유를 첨가한 배지를 $30{\circ}C$에서 72시간 정치배양하는 것이었다. 아세톤으로 침전시킨 조효소(crude enzyme)는 일차로 DEAE-cellulose, 2차로 Sephadex G-100 gel filtration에 의하여 1,387배로 정제되었고 이때의 수율은 6.2%이였다. 정제된 효소의 최적 온도는 $45{\circ}C$ 최적 pH는 4.5이었으며, 기질로서 ONPG와 유당에 대한 Km값은 각각 $3.57{\times}10^3M$과 $83.3{\times}10^3M$, Vmax값은 각각 33.0 unit/mg protein과 15.38unit/mg protein이었다. 활성화 에너지는 9,900cal/mol이었으며 효소활성 및 안정제로 금속이온을 필요로 하지 않았다. 50ml의 탈지유, 4.8%유당 용액, 유청용액에 효소 5ml(182 unit/ml)를 침가하여 $45^{\circ}C$에서 10시간 반응시켰을 때의 유당 분해율은 각각 65%, 70%, 78%를 나타내었다.

• Journal of Microbiology and Biotechnology
• /
• 제24권5호
• /
• pp.675-682
• /
• 2014

Approximately 50% of people in the world experience abdominal flatulence after the intake of foods containing galactosides such as lactose or soybean oligosaccharides. The galactoside hydrolyzing enzymes of ${\alpha}$- and ${\beta}$-galactosidases have been shown to reduce the levels of galactosides in both the food matrix and the human gastrointestinal tract. This study aimed to optimize the production of ${\alpha}$- and ${\beta}$-galactosidases of Bifidobacterium longum subsp. longum RD47 with a basal medium containing whey and corn steep liquor. The activities of both enzymes were determined after culturing at $37^{\circ}C$ at pH 6.0 for 30 h. The optimal production of ${\alpha}$- and ${\beta}$-galactosidases was obtained with soybean oligosaccharides as a carbon source and proteose peptone no. 3 as a nitrogen source. The optimum pH for both ${\alpha}$- and ${\beta}$-galactosidases was 6.0. The optimum temperatures were $35^{\circ}C$ for ${\alpha}$-galactosidase and $37^{\circ}C$ for ${\beta}$-galactosidase. They showed temperature stability up to $37^{\circ}C$. At a 1 mM concentration of metal ions, $CuSO_4$ inhibited the activities of ${\alpha}$- and ${\beta}$-galactosidases by 35% and 50%, respectively. On the basis of the results obtained in this study, B. longum RD47 may be used for the production of ${\alpha}$- and ${\beta}$-galactosidases, which may reduce the levels of flatulence factors.

• Journal of Microbiology and Biotechnology
• /
• 제9권2호
• /
• pp.201-205
• /
• 1999

The effects of growth temperature and a carbon source on the expression of $\beta$-galactosidase gene of Lactococcus lactis ssp. lactis ATCC 7962 (L. lactis 7962) were investigated. At $25^{\circ}C$, L. lactis 7962 had a higher $\beta$-galactosidase activity than cells grown at $30^{\circ}C$ or $37^{\circ}C$, although cells grew most quickly at $37^{\circ}C$ The highest $\beta$-galactosidase activity was observed in cells grown in M17 with lactose (l %) followed by cells grown in a galactose (1 %) medium. L. lactis 7962 exhibited the minimum $\beta$-galactosidase activity in glucose media, indicating catabolite repression. When the cellular levels of $\beta$-galactosidase mRNA were examined using slot blot hybridization, no significant differences were observed between cells grown at $25^{\circ}C$ and cells at $30^{\circ}C$ or $37^{\circ}C$ in the same media. This suggests that the quantity of $\beta$-galactosidase mRNA may not be the reason for the higher $\beta$-galactosidase activities of L. lactis 7962 at $25^{\circ}C$ The level of ccpA (Catabolite Control Protein) transcript remained almost constant during the exponential growth phase irrespective of a carbon sourse.

• Journal of Microbiology and Biotechnology
• /
• 제15권4호
• /
• pp.689-693
• /
• 2005

Bacillus sp. JB-99, when grown in a chemically defined medium containing lactose as a carbon source, yielded 3,860 U/ml extracellular $\beta$-mannanase, which was high compared to other examined carbon sources. Among the nitrogen sources, yeast extract enhanced the enzyme activity. The enzyme production was growth-associated. The enzyme was optimally active at $65^{\circ}C$, pH 10, and had a half-life of 190 min at $65^{\circ}C$. N-Bromosuccinamide and $AgNO_3,\;CuSO_4$, and $HgCl_2$ strongly inhibited the enzyme, whereas $Ca^{2+}$ stimulated the enzyme activity. The $\alpha$-galactosidase enzyme production was not found in any of the enzyme assays.

• Journal of Pharmaceutical Investigation
• /
• 제15권3호
• /
• pp.100-112
• /
• 1985

Dissolution characteristics of flurbiprofen solvent deposited on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, lactose and corn starch were studied to evaluate the pharmaceutical aspects of solvent deposition method where drug was solvent deposited on the surface of excipients. In a solvent deposition system, the drug to excipient ratio and kind of excipient affect much on dissolution rates of flurbiprofen. The solvent deposition system formation was confirmed by scanning electron microscope. By increasing the amounts of matrix, it was possible to enhance the dissolution rate of flurbiprofen solvent deposition system. The amount of flurbiprofen dissolved from ${\beta}-cyclodextrin$ deposition system (1:10) at 60 minutes was enhanced 6.5 times in water and 28 times in simulated gastric juice compared with flurbiprofen alone. Flurbiprofen solvent deposited system (1:10) enhanced dissolution rate greater than inclusion complex and dispersion system.

• 한국식품영양학회지
• /
• 제12권1호
• /
• pp.50-54
• /
• 1999

Effect of galactooligosaccharides produced by the $\beta$-galactosidase from Aapwefillua niger CAD 1 on the growth of Bifidobacterium infantis KCTC 3127 Bifidobacterium longum KCTC 3128 and Bifidobacterium bif-idum ATCC 11863 were investigated. Bifidbacterium infantis Bifidobacterium longum and Bifidobacterium bif-idum were in the logarithmic growth phase after 6hr incubation at 37$^{\circ}C$. Bifidobacterium infantis was in the stationary phase after 24hr incubation at 37$^{\circ}C$. The growth rate of B. bifidum containing galactooligo-saccharides and raffinose in MRS broth increased up to 18%, 8% and 7% compared to glucose galac-tose and lactose during 48hr incubation. The growth rate of B. infantis and B. longum contatining galacto-oligosaccharides and raffinose in MRS broth increased up to both 6% and 8% and both 13% and 10% compared to glucose and galactose during 48hr incubation.

• KSBB Journal
• /
• 제23권6호
• /
• pp.474-478
• /
• 2008

효율적인 UDP-glucose regeneration system을 구축하기 위해서 재순환 시스템에 관여하는 4가지 효소 (UDP-glucose pyrophosphorylase, UDP-Kinase gene, UDP-galactose 4-epimerase, and $\beta$-1, 4-galactasyltrasnsferase)들을 E. coli AD202에서 발현 시켜 Disaccharide 합성 정도를 보았다. Disaccharide는 0.5 mM IPTG 농도에서 가장 높은 농도를 나타내었다. 대조구와 비교한 결과 LacNAc 농도는 1.34 mM로 10배 정도 정가하였고, lactose 농도는 0.39 mM로 대조구보다 2.6배 증가하였다. 총 disaccharide 농도는 1.73 mM 이며, 대조구 보다 6.5배 높은 생산성을 보였다. 본 논문은 결과는 metabolic flux regeneration으로 disaccharides 합성을 증가시킬 수 있다는 것을 보여주었다.

• 한국식품과학회지
• /
• 제12권2호
• /
• pp.88-96
• /
• 1980

아미노-카르보닐 반응에 대한 반응 조건을 검토하고 반응성에 미치는 아미노산(酸)의 영항에 대하여 검토한 결과 다음과 같은 결과를 얻었다. 1. 아미노-카르보닐 반응은 알칼리성이 강할수록 melanoidin 생성량은 크게 증대되었으며, 아미노산의 등전점 이상에서 반응 속도는 더욱 증가되는 것으로 나타났다. 2. 당(糖)과 아미노산(酸)의 몰 분비(分比)가 1:1일 때까지 melanoidin 생성량은 직선적으로 증가되었으며, 당과 아미노산(酸)은 1:1로 결합함을 알 수 있었다. 3. 아미노-카르보닐 반응은 시간과 반응 온도에 높은 의존성을 보였으며, 동(同) 몰의 glucose-glycine 계(系)에서의 활성화 에너지는 37.5Kcal/mole이었다. 4. 사용된 아미노산(酸) 중(中)에서 glycine, lysine 및 $\beta$-alanine이 당과의 반응성이 현저하게 높았으며, 산성(酸性)아미노산(酸)의 반응성은 아주 낮았다. 따라서 산성(酸性) 아미노산(酸)의 측쇄(測鎖)의 카르복실기(基)는 아미노기(基)의 반응성에 가장 저해(沮害) 결과(結果)를 나타내었다. 5. 사용된 당류(糖類)의 반응성은 다음의 순서로 나타났다. Xylose>arabibose>fructose>glucose>maltose>lactose.

• Preventive Nutrition and Food Science
• /
• 제5권3호
• /
• pp.153-159
• /
• 2000

A 4.4 kb DNA fragment encompassing lacA (galactoside acetyltransferase) and lacZ($\beta$-galactosidase) genes from Lactococus lactis ssp. lactis ATCC 7962 (L. lactis 7962) was introduced ito a Lac strain, Lactococcus lactis ssp. lactis MG1363 (L. lactis MG1363) by using a lactococcal expression vector, pMG36e and expression level of lacZ was examined. Growth rates and $\beta$-galactosidase ($\beta$-gal) activities of MG1363 cells carrying recombinant plasmid, pMLZ3, on M17 broth containing different carbon sources (1%, w/v) were examined. Contrary to the expectations, MG1363 [pMLZ3] grown on lactose showed the lowest enzyme activity (17 units) and cells grown on galactose had the highest $\beta$-gal activity (41 units). Cells grown on glucose had intermediate activity (33 units). These activities are about one tenth of the values observed in L. lactis 7962 where lacZ is present as a single-copy gene in the chromosome. When the cellular concentrations of lacZ transcript were examined using slot blot hybridization, it was found that MG1363[pMLZ3] produced sufficient amounts of transcript. These results indicate that either proteolytic degradation of $\beta$-gal or other regulatory mechanism prevent the translation or accumulation of $\beta$-gal in L. lactis MG1363 cells. In regard to regulation, the presence of the ccpA gene in L. lactis MG1363 was confirmed by Southern blot.