• Journal of Microbiology and Biotechnology
• /
• v.24 no.10
• /
• pp.1427-1437
• /
• 2014

Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in the conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide-degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as the nonionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under the optimized condition, the production of FPase, endoglucanase, ${\beta}$-glucosidase, xylanase, and ${\beta}$-xylosidase was achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in the saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison with commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contained higher relative activities of ${\beta}$-glucosidase and core hemicellulases (xylanase and ${\beta}$-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possesses balanced cellulolytic and xylanolytic activities required for the efficient saccharification of lignocellulosic biomass feedstocks, and supplementation of external ${\beta}$-glucosidase or xylanase was dispensable. The work thus demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for the biomass conversion industry.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.235-238
• /
• 2008

We examined butanol fermentation by Clostridium beijerinckii NCIMB 8052 using various hydrolyzates obtained from rice bran which is one of the most abundant agricultural by-products in Korea and Japan. In order to increase the amount of fermentable sugars in the hydrolyzates of rice bran, various hydrolysis procedures were applied. Total eight different hydrolyzates were prepared using rice bran (RB) and defatted rice bran (DRB) with enzyme or acid treatment and both. Each hydrolyzate was evaluated in terms of total sugar concentration and butanol production after fermentation by C. beijerinckii NCIMB 8052. Acid treatment yielded more sugar than enzyme treatment and combined treatment with enzyme and acid yielded even more sugars as compared to single treatment with enzyme or acid. As a result, the highest sugar concentration (33 g/L) was observed from the hydrolyzate from DRB (100 g/L) with combined treatment using enzyme and acid. Prior to perform fermentation of the hydrolyzates, we examined the effect of P2 solution containing yeast extract, buffer, minerals, and vitamins on production of butanol during the fermentation. Fermentation of the hydrolyzates with or without additionof P2 was performed using C. beijerinckii NCIMB 8052 in a 1 L anaerobic bioreactor. Although the hydrolyzates RB were able to support growth and butanol production, addition of P2 solution into the hydrolyzates significantly improved cell growth and butanol production. Highest butanol production (12.24 g/L) was observed from the hydrolyzate of DRB with acid and enzyme treatment after supplementation of P2 solution.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.5
• /
• pp.482-490
• /
• 2009

We examined butanol fermentation by Clostridium beijerinckii NCIMB 8052 using various hydrolyzates obtained from rice bran, which is one of the most abundant agricultural by-products in Korea and Japan. In order to increase the amount of fermentable sugars in the hydrolyzates of rice bran, various hydrolysis procedures were applied. Eight different hydrolyzates were prepared using rice bran (RB) and defatted rice bran (DRB) with enzyme or acid treatment or both. Each hydrolyzate was evaluated in terms of total sugar concentration and butanol production after fermentation by C. beijerinckii NCIMB 8052. Acid treatment yielded more sugar than enzyme treatment, and combined treatment with enzyme and acid yielded even more sugars as compared with single treatment with enzyme or acid. As a result, the highest sugar concentration (33 g/l) was observed from the hydrolyzate from DRB (100 g/l) with combined treatment using enzyme and acid. Prior to fermentation of the hydrolyzates, we examined the effect of P2 solution containing yeast extract, buffer, minerals, and vitamins on production of butanol during the fermentation. Fermentation of the hydrolyzates with or without addition of P2 was performed using C. beijerinckii NCIMB 8052 in a 1-1 anaerobic bioreactor. Although the RB hydrolyzates were able to support growth and butanol production, addition of P2 solution into the hydrolyzates significantly improved cell growth and butanol production. The highest butanol production (12.24 g/l) was observed from the hydrolyzate of DRB with acid and enzyme treatment after supplementation of P2 solution.

• Microbiology and Biotechnology Letters
• /
• v.10 no.3
• /
• pp.177-184
• /
• 1982

Studies were carried out to investigate the optimal culture conditions for the production of penicillinase using a strain of Streptomyces sp. isolated from soil, YS-40. Among the carbon and nitrogen sources, glucose and L-asparagine increased the peniciilinase production. The addition of M $n^{＋＋}$, $Ca^{＋＋}$ and L $i^{＋}$ increased the enzyme production, but depressed by F $e^{＋＋＋}$, F $e^{＋＋}$, $Mg^{＋＋}$, Z $n^{＋＋}$, A $g^{＋＋}$, $Ba^{＋＋}$ and S $n^{＋＋}$. L-Leucine slightly increased the enzyme production but L-histidine, L-methionine depressed. Among the vitamins riboflavine, i-inositol, hesperidine, niacin-amide, biotin, folic acid, DL-$\alpha$-lipoic acid increased the enzyme formation. The addition of cephradine, cephalexin, ampicillin, cloxacillin more increased the enzyme formation than that of other$\beta$-lactam antibiotics and antibiotics. Optimal pH and temperature on the enzyme formation was pH 7.0 and 28$^{\circ}C$ respectively Amount of the enzyme production reached at maximum with incubation for 3 days on the optimal condition.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.1 no.1
• /
• pp.18-21
• /
• 1996

A continuous production of fructooligosaccharides from sucrose was investigated by fructosyltransferase immobilized on a high porous resin, Diaion HPA25. The optimum pH(5.5) and temperature(55$^{\circ}C$) of the enzyme for activity was unaltered by immobilization, and the immobilized enzyme became less sensitive to the pH change. The optimal operation conditions of the immobilized enzyme column for maximizing the productivity were as follows: 600g/L of sucrose feed concentration, flow rate of superficial space velocity 2.7h-1. When the enzyme column was run at 50$^{\circ}C$, about 8% loss of the initial activity of immobilized enzyme was observed after 30 days of continuous operation, during which high productivity of 1174g/L$.$h was achieved. The kinds of products obtained using the immobilized enzyme were almost the same as those using soluble enzymes or free cells.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.4
• /
• 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.

• Microbiology and Biotechnology Letters
• /
• v.18 no.3
• /
• pp.244-250
• /
• 1990

A bacterium capable of hydrotyzing raw starch was isolated from soil, which was identified as a strain of Bacillue. The effects of culture conditions and medium compositions on the enzyme production were investigated. Among tested carbon sources, soluble starch and wheat starch were most effective for the production of the enzyme, and the level of concentration for the optimal enzyme production was 0.5%. For nitrogen sources, polypeptone was best for the enzyme production, with the level of 0.5%. The enzyme was maximally produced by cultivating the organism at medium of initial pH 6.5, and temperature of $35^{\circ}C$. The enzyme was partially purified by Sepharose CL-6B gel filtration and DEAESephacel ion-exchange chromatography. The optimal pH and temperature for the enzyme reaction were 6.5 and $70^{\circ}C$, respectively. The enzyme most stable at pH 8.0, and temperature up to $60^{\circ}C$. In kinetic studies, the k, values for corn, wheat, rice and potato starch were 1.7, 1.4,2.5 and 1.090, respectively.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1648-1653
• /
• 1999

A strain of potential producer of fibrinolytic enzyme was isolated from shrimp Jeot-Gal, a tiny salted shrimps, and identified as Bacillus sp.. The preliminary experiment showed an enzyme yield of 18 U/mL in medium for screening. The carbon, nitrogen and salts significantly influenced the fibrinolytic enzyme production. An optimized medium containing 2% skim milk, 2% soluble starch and 3% NaCl (pH 7.5) after 72 hrs fermentation time at $37^{\circ}C$ yielded 3-fold increase in enzyme production, 62 U/mL.

• KSBB Journal
• /
• v.14 no.5
• /
• pp.600-605
• /
• 1999

For the production of angiotensin I converting enzyme inhibitory peptides as a material for antihypertensive functional foods from animal blood produced in slaughterhouse, the optimum condition for enzymatic hydrolysis to yield a peptide fraction of the highest activity were investigated with a respect of industrial production. Among several industrially-usable enzymes tested, $Alcalase^？$ produced hydrolysates of the highest activity from total plasma and purified albumin. $IC_50$ values of albumin hydrolysate and its third fraction separated by gel chromatography were 0.5 and 0.02 mg/mL, respectively. The fraction was found to be obtained by a simple ultrafiltration using a membrane of MW cutoff 1,000. The possibility for the industrial production of antihypertensive peptides from animal blood plasma protein was suggested.

• Microbiology and Biotechnology Letters
• /
• v.9 no.2
• /
• pp.91-97
• /
• 1981

A thermophilic soil isolate Bacillus sp. Y-127 was selected for the production of thermostable amylase. The strain was used for the enzyme production and the thermostable amylase was characterized. The optimum cultural conditions for the enzyme production were 6$0^{\circ}C$ at pH 7.0 for 32 hours using a mineral medium containing 2% soluble starch and 0.2% yeast extract. The extra-cellular enzyme was purified about 123-folds with about 6% recovery. The purified enzyme was stable at pH between 4.0 and 7.0, and temperature up to 6$0^{\circ}C$.