• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1151-1157
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• 2003

The surfactant Tween 80 was evaluated for its ability to influence cumulative gas production, cellulose digestion, and enzyme activities by mixed ruminal microorganisms grown on barley grain or Orchardgrass hay. The addition of Tween 80 at a level of 0.10% significantly (p<0.05) decreased the cumulative gas production rate from both barley grain or Orchardgrass hay substrates. However, 0.05% Tween 80 did not affect gas production rates compared to the control treatment. The addition of 0.05% Tween 80 to cultures growing on barley grain resulted in a significant increase in cellulase (90.01%), xylanase (90.73%) and amylase (487.25%) activities after 30 h incubation. Cultures utilizing Orchardgrass hay had a significant increase in cellulase (124.43%), xylanase (108.86%) and amylase (271.22%) activities after 72 h incubation. These increases in activities were also observed with cultures supplemented with 0.10% Tween 80 throughout all the incubation times tested. These results indicated that the addition of 0.05% Tween 80 could greatly stimulate the release of some of key enzymes without decreasing cell growth rate in contrast to trends reported with aerobic microorganism. Our data indicates potential uses of the surfactant Tween 80 as a feed additive for ruminant animals.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.220-225
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• 2012

In batch culture for Poly(vinyl alcohol) (PVA)-degrading enzyme (PVAase) production by a mixed culture, higher pH (pH 7.5) was favorable for PVAase production at the prophase of cultivation, but lower pH (pH 7.0) was favorable at the anaphase. This situation was caused by the fact that the optimum pH for different key enzymes [PVA dehydrogenase (PVADH) and oxidized PVA hydrolase (OPH)] production is various. The activity and average specific production rate of PVADH reached the highest values at constant pH 7.5, whereas those of OPH appeared at pH 7.0. A two-stage pH control strategy was therefore developed and compared for its potential in improving PVAase production. By using this strategy, the maximal PVAase activity reached 2.05 U/ml, which increased by 15.2% and 24.2% over the fermentation at constant pH 7.5 and 7.0.

• 한국유기농업학회지
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• 제12권2호
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• pp.231-241
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• 2004

In recent years, many researches are actively undertaken for environmental-friendly animal production according to the increased understanding about food safety because of the outbreak of various diseases such as mad cow disease, Foot and mouth disease and Poultry Influenza virus. However, high quality(higher safety)- animal production may not be successful without increasing of disease resistance of animal and the improvement of feeding environment. To increase the disease resistance is able to be accomplished by stimulating the immune function. The present study was undertaken to investigate the effects of enzyme mixture reinforced with ${\beta}$-glucanase activity which degrade polysaccharide to release ${\beta}$-glucan known as stimulator of immune function on the change of milk production and somatic cell count. After 12weeks of experimental feeding, milk production tended to be increased and somatic cell count was decreased from average $227{\times}10^4$ to $37.1{\times}10^4$. Milk protein and solid-fat content were tended to increase but milk fat showed decreasing tendency by the feeding of enzyme mixture. All together, it has been suggest6d that the improvement of high quality milk production may be possible through the dietary addition of immune modulating enzyme mixture in lactating dairy cows.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.960-967
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• 2011

Tannin acyl hydrolase, also known as tannase, is an enzyme with important applications in the food, feed, pharmaceutical, and chemical industries. However, despite a growing interest in the catalytic properties of tannase, its practical use is very limited owing to high production costs. Several studies have already demonstrated the advantages of solid-state fermentation (SSF) for the production of fungal tannase, yet the optimal conditions for enzyme production strongly depend on the microbial strain utilized. Therefore, the aim of this study was to improve the tannase production by a locally isolated A. niger strain in an SSF system. The SSF was carried out in packed-bed bioreactors using polyurethane foam as an inert support impregnated with defined culture media. The process parameters influencing the enzyme production were identified using a Plackett-Burman design, where the substrate concentration, initial pH, and incubation temperature were determined as the most significant. These parameters were then further optimized using a Box-Behnken design. The maximum tannase production was obtained with a high tannic acid concentration (50 g/l), relatively low incubation temperature ($30^{\circ}C$), and unique low initial pH (4.0). The statistical strategy aided in increasing the enzyme activity nearly 1.97-fold, from 4,030 to 7,955 U/l. Consequently, these findings can lead to the development of a fermentation system that is able to produce large amounts of tannase in economical, compact, and scalable reactors.

• 미생물학회지
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• 제16권2호
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• pp.47-61
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• 1978

Strptomyces albus T-12 which ahd been isolated and identified in the laboratory, was selected for the studies on the cultural conditions on the production of D-xylose iosmerase and the enzymological characteristics using the partially purified enzyme. The best results in the enzyme production came from D-xylose medium than wheat bran. The divalent metla ions as $Co^{2+},\;Fe^{2+},\;Zn^{2+}\;and\;Cu^{2+}$ retard or inhibit the cell-growth at the early stages of mycelia propagations, and T-12 strain is especially sensitive to $Co^{2+}$. After 60 hours of shaking cultivation at $30^{\circ}C$ and 200 rpm, a maximum enzyme activitz, 0.49 enzyme units, was obtained. Cell-free enzyme obtained from mycelia heat-treated in the prescence of 0.5mM $Co^{2+}$, showed a 2.4-fold increase in specific than the enzyme from untreated mycelia. The specific activity of the purified enzyme through Sephadex G-150 columm showed 180 fold to the crude enzyme. The effective activators of the enzyme appeared to be $Mg^{2+}\;and\;Co^{2+}$ ions, and it exhibited the maximal enzyme activity showed at pH 7.0 and at tempersture around $80^{\circ}C$ when $Mg^{2+}\;and\;Co^{2+}$ ions were added. The enzyme isomerized D-glucose, D-xylose, D-ribose, L-arabinose, D-mannose, and L-rhamnose in the present of $Mg^{2+}\;and\;Co^{2+}$ ions as an activatiors. $Mg^{2+}\;and\;Co^{2+}$ ions were non-competitively bound at different allosterix sites of enzyme molecule. $Mg^{2+}(5mM)\;or\;Co^{2+}(1.0mM)$ protected against the thermal denaturations of the enzyme activities. The michelis constant(Km) and $V_{max}$ values of the emzyme for D-glucose and D-xylose were 0.52M, $2.12{\mu}moles/ml{\cdot}min.\;and\;0.28M,\;0.65moles/ml{\cdot}min.$, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.1053-1058
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• 2008

A total of 392 twenty eight week-old laying hens was used to study the effects of dietary inclusion of solvent-extracted palm kernel cake (PKC) (0%, 12.5% and 25%) and enzyme (mixture of mannanase, ${\alpha}$-galactosidase and protease) supplementation (0 kg/t, 1 kg/t and 2 kg/t) on the performance of laying hens. The levels of PKC did not significantly influence nitrogen corrected true metabolizable energy (TMEn) of the diets. Enzyme-supplemented PKC had significantly higher AME and TMEn values than PKC diets with no enzyme supplementation. Dietary inclusion of 12.5% and 25% PKC in the diets of laying hens did not adversely affect mean egg production or daily egg mass. However, layers consumed significantly more PKC-based diets and had significantly poorer feed conversion ratios (FCR) than controls. However, the feed intake and FCR of hens provided the 12.5% PKC-based diets with enzyme supplementation at 1 kg/t did not differ from the controls. Dietary inclusion of PKC or enzyme did not affect eggshell quality, but egg yolk colour was significantly paler when layers were fed the 25% PKC diet.

• Journal of Microbiology
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• 제40권1호
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• pp.20-25
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• 2002

An extracellular PHB depolymerase was purified from P. simplicissimum LAR13 cultural medium by Sepharose CL-6B chromatography. When the fungus was grown in a basal salt medium with poly(3-hydroxybutyrate) (PHB) as the sole carbon source, PHB depolymerase production reached maximum at its stationary phase. The mycelial growth rate was higher at 37$^{\circ}C$ than at 30$^{\circ}C$ and even higher than at 25$^{\circ}C$, However, the enzyme production was lower at 37$^{\circ}C$ than 30$^{\circ}C$ or 25$^{\circ}C$. The isolated enzyme is composed of a single polypeptide chain with a molecular mass of about 36 kDa as determined by SDS-PAGE. The optimum conditions for the enzyme activity are pH 5.0 and 45$^{\circ}C$. The enzyme was stable for 30 min at a temperature lower than 50$^{\circ}C$, and stable at pH higher than 2.0 but it was unstable at pH 1.0.1 mM Fe$\^$2+/ reduced the enzyme activity by 56% and the enzyme was inhibited almost completely by 4 mM Fe$\^$2+/ . The enzyme was partially inhibited by phenylmethylsulfonyl fluoride and was very sensitive to diazo-DL-norleucine methyl esters dithiothreitol and mercuric ion. However, N-p - tosyl - L - Iysinechloromethyl ketone, p -hydroxymercuricbenzoate and N- acetylimidazole had no influence upon its activity.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.304-310
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• 1995

A thermophilic bacterium producing the extracellular cellulase-free xylanase was isolated from soil and has been identified as Bacillus sp. The optimal growth temperature was 50$\circ$C and the optimal pH, 7.0. Under the optimal growth condition, maximal xylanase production was 2.2 units/ml in the flask culture. The enzyme production was induced by xylan and xylose, but was repressed by sucrose or trehalose. The partially purified xylanase was most active at 70$\circ$C. It was found that the enzyme was stable at 65$\circ$C for 10 hours with over 75% of the activity. The enzyme was most active at pH 7.0 and retained 90% of its maximum activity between pH 5.0 and pH 9.0 though Bacillus sp. was not grown on alkaline conditions (>pH 8.0). In addition, the activity of xylanase was over 60% at pH 10.0. At the ambient temperature, the enzyme was stable over a pH range of 5.0 to 9.0 for 10 h, indicating that the enzyme is thermostable and alkalotolerant. The activity of xylanase was completely inhibited by metal ions including Hg$^{2+}$ and Fe$^{2+}$, while EDTA, phenylmethylsulfonyl fluoride (PMSF), $\beta$-mercaptoethanol and SDS didn't affect its activity. The enzyme was also identified to exert no activity on carboxymethylcellulose, laminarin, galactomannan, and soluble starch.

• KSBB Journal
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• 제8권4호
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• pp.307-312
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• 1993

Polystyrene계 음이온 교환수지인 Diaion PA 412에 Aureobasidium pullulans 기원의 fructosyltransferase를 crude enzyme 상태로 고정화하여 fructo-oligosaccharides의 생산을 검토하였다. 고정화 효소의 최적 반응 pH 및 온도는 각각 pH 5.0, $55^{\circ}C$. 이었고 고정화에 의해 열안정성이 크게 증가하였다. 고정화 효소에 의한 fructo-oligosaccharids 생성의 효소 반응 경향은 free cell 및 soluble enzyme과 거의 유사하여 최종 반응산물 중의 당 조성 이 동일하였다. 고정화 효소를 repeated-batch 방법으로 운전하여 fructo-oligosaccharides 생산공정에 적용해 본 결과 $50^{\circ}C$에서 20일까지 안정성을 유지하였다.

• 생명과학회지
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• 제7권1호
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• pp.30-38
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• 1997

내열성 {\alpha}$-amulase를 생산하는 미생물을 분리하기 위하여 각종 분리원으로 시료를 채취하여 55$^{\circ}C$ 이상에서 생육하고 가장 내열성 {\alpha}$-amulase 생산능이 우수한 균주를 분리, 동정한 결과 thermophilic Bacilus 속으로 추정되었다. 균체생육과 효소생산의 최적온도는 60~$65^{\circ}C$였고, 초발 pH8.0에서 가장 높은 효소생산능을 보였다. {\alpha}$-amulase 생산에 가장 양호한 탄소원은 soluble starch, dextrin, prtato starch, corn starch 등의 다당류이었으며 glucose, fructose 등의 단당류에서는 효소생산이 미약하거나 억제를 받았다. {\alpha}$-amulase 생산에 가장 중요한 질소원은 yeast extract이었따. 0.1% $CaCl_2{\cdot}2H_2O$, 0.001%의 Tween-80의 첨가는 {\alpha}$-amulase 생산성을 증가시켰다. 본 공사균이 생산한 조효소액의 특성을 검토해 본 결과, 8$0^{\circ}C$에서 최적 효소활성을 보였으며, 10$0^{\circ}C$에서도 23%의 잔존활성을 나타내었다. 최적 pH는 5.0이었다. $Ca^{2+}$은 효소활성 증진에는 영향을 미치지 않았다. 공시균으로부터 분리한 genomic DNA를 중온성 BAcillus subtilis KCTC 1024에 형질전환시킨 결과, transformant는 wild type에 비하여 약 2배의 효소활성이 증가되었다.