• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.543-550
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• 1992

The production of xylanase and $\beta$-xylosidase was investigated in submerged culture of Aspergillus niger NRC 107. The maximum production occurred when the pH was controlled at 6.0 during the fermentation. Among the various carbon sources investigated, corn-cob xylan (1.5%, w/v) yielded maximal production of the enzymes. The $NaNO_{3}$ was the most favorable nitrogen source for enzyme production and $KH_2P0_4$ concentration at 0.3%(w/v) was found to be optimum. Incorporation of wheat bran to the culture medium improved xylanase production. Addition of L( -) sorbose to the culture medium promoted the secretion of $\beta$-xylosidase. It was possible to increase the production of xylanase (39.43 units/ml) and that of $\beta$-xylosidase (4.2 unitslml) by submerged culturing the A. niger NRC 107 in the modified medium.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1698-1707
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• 2013

Optimization of the dietary formulation is the most effective way to reduce methane. Nineteen feed ingredients (brans, vegetable proteins, and grains) were evaluated for their potential to generate methane and change methanogen diversity using an in vitro ruminal fermentation technique. Feed formulations categorized into high, medium and low production based on methane production of each ingredient were then subjected to in vitro fermentation to determine the real methane production and their effects on digestibility. Methanogen diversity among low, medium and high-methane producing groups was analyzed by PCR-DGGE. The highest methane production was observed in Korean wheat bran, soybean and perilla meals, and wheat and maize of brans, vegetable protein and cereal groups, respectively. On the other hand, corn bran, cotton seed meal and barley led to the lowest production in the same groups. Nine bacteria and 18 methanogen 16s rDNA PCR-DGGE dominant bands were identified with 83% to 99% and 92% to 100% similarity, respectively. Overall, the results of this study showed that methane emissions from ruminants can be mitigated through proper selection of feed ingredients to be used in the formulation of diets.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.188-194
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• 2002

To study the effect of wheat bran and lactic acid producing bacteria (LAB) on the performance of calves, 20 crossbred male cattle calves (day old), distributed into two groups were fed on calf starters containing 50 or 0% maize grain, along with green berseem ad libitum and milk as per body weight. Each group was further divided into two sub groups and one subgroup of each group was supplemented with mixed culture of LAB (Lactobacillus acidophilus L. casei, L. Jugarti). Milk feeding was discontinued after 8 weeks of age. The addition of culture increased (p<0.05) DM intake in calves receiving grainless diet from eighth week to the thirteenth one. There was about 21% higher body weight gain and 14% lower feed : gain ratio in culture supplemented calves. DM digestibility was significantly lower (p<0.05) in calves getting grain without culture. The crude protein NDF and ADF digestibility was higher (p<0.05) in grainless than the grain fed group. No major change on rumen fermentation pattern among different treatments was found. The concentration of total volatile fatty acids (TVFA) and protozoa count was higher (p<0.05) in grain fed group. However, lactic acid concentration was higher and rumen pH was lower due to culture feeding. The incidence as well as severity of diarrhoea was reduced in culture supplemented group. The results indicate that crossbred calves can be reared successfully on grainless diet and berseen fodder. The performance of calves was also improved by LAB supplementation.

• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.153-158
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• 1977

These experiments were conducted to investigate the condition of the production and the heat resistance of the acid protease by Rhizopus japonicus S-62. The results obtained were as follows: 1) The optimum concentrations of sucrose, yeast, ammonium chloride and sodium phosphate monobasic added to the wheat bran medium in the acid protease production were 0.5％, 2.0％, 0.4％, and 0.4％, respectively. 2) KH$_2$PO$_4$ and NaH$_2$PO$_4$ were the most effective as the heat resistant agents. 3) When the enzyme solutions added with KH$_2$PO$_4$ and NaH$_2$PO$_4$ to the concentration of 2％ were heated for 10 min, at 50$^{\circ}C$, their residual activities were 100％, respectively. 4) The heat resistant effects of KH$_2$PO$_4$ and NaH$_2$PO$_4$ were not observed almost above 55$^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.251-259
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• 1990

Asp. usumii IAM 2185 was selected as a strain producing the powerful raw starch digesting glucoamylase. The optimum initial pH, the optimum temperature and the optimum cultural time for the enzyme production on wheat bran medium were pH 6-8,25-$30^{\circ}C$ and 72 hrs, respectively. The addition of ammonium nitrate and albumin on wheat bran medium, respectively, increase slightly the enzyme production. The enzyme was purified by ammonium sulfate fractionation, CM-cellulose and DEAE-cellulose column chromatography. The specific activity of the purified enzyme was 34.3 U/mg protein and the yield of enzyme activity was 10.3%. The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis and its molecular weight was estimated to be 67,000 by SDS polyacrylamide disc gel electrophoresis. The isoelectric point for the purified enzyme was pR 3.7. The optimum temperature and optimum pH were $60^{\circ}C$and pH 3.0 and the purified enzyme was stable in the pH range of 1.0-11.0. The purified enzyme was stable below $50^{\circ}C$ and its thermostability was greatly increased by the addition of $Ca^{2+}$. The purified enzyme showed a high hydrolysis rate on various raw starches such as corn, rice, yam, arrow root, sweet potato and glutinous rice.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.63-67
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• 1995

Broiler processing waste(offal) was homogenized and treated with the combination of acids. The offal was autolyzed(ensiled) at $25^{\circ}C$ for 72 hrs and analyzed for pH and fatty acid profile. The proximate composition and microbial content change of the autolyzed offal by mixing with wheat bran and ovendrying were evaluated. The initial pH value of the homogenized offal, 6.52 came down to 2.75 within 5 min after acidification and increased silightly to $3.06{\sim}2.92$ during autolysis. The proximate composition and fatty acid profile of the autolyzed offal were not substantially different from the unautoylzed offal. However, the log CFU(colony forming units)/g of total plate counts and fungal counts decreased from 7.45 and 7.11 to 3.39 and 2.03 after autolysis, respectively.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.207-212
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• 2010

A bacterium producing the extracellular mannanase was isolated from Korean soybean paste. The isolate WL-8 has been identified as Bacillus subtilis on the basis on its 16S rRNA sequence, morphology and biochemical properties. The mannanase productivity of strain WL-8 was increased in LB broth by addition of wheat bran. The maximum mannanase productivity was reached to approximately 20 U/ml in LB medium supplemented with 6% wheat bran. A gene encoding the mannanase of WL-8 was cloned into Escherichia coli and its nucleotide sequence was subsequently determined. The mannanase gene consisted of 1,086 nucleotides encoding a polypeptide of 362 amino acid residues. The deduced amino acid sequence was highly homologous with those of several mannanases from B. subtilis belonging to GH family 26. Reaction temperature and pH profiles were investigated using the culture filtrate and cell-free extract of the recombinant E. coli carrying a WL-8 mannanase gene, respectively. Optimal conditions for the two fractions occurred at pH 5.5 and $60^{\circ}C$. The cell-free extract showed higher mannanase activity than the culture filtrate at above $60^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.339-346
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• 2014

A bacterial strain was isolated from homemade doenjang (Korean fermented soybean paste) as a producer of the extracellular ${\beta}$-galactosidase, capable of hydrolyzing lactose to liberate galactose and glucose residues. The isolate YB-1414 has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. The production of ${\beta}$-galactosidase by B. licheniformis YB-1414 reached maximum levels of 6.2 U/ml in culture medium containing wheat bran (1%) and yeast extract (2.5%) as carbon and nitrogen sources, respectively. Particularly, the insoluble fraction was more effective for ${\beta}$-galactosidase production than the soluble extract of wheat bran. The enzyme exhibited maximum activity for hydrolysis of para-nitrophenyl-${\beta}$-D-galactopyranoside (pNP-${\beta}Gal$) under reaction conditions of pH 6.0 and $55-60^{\circ}C$. Its hydrolyzing activity for pNP-${\beta}Gal$ was drastically decreased by the addition of low concentrations of galactose, but only slightly decreased by glucose, with 85% of maximal activity in the presence of 400 mM glucose.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.144-155
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• 1987

A potent fungus producing milk clotting enzyme with fairly weak proteolytic activity was isolated from various soil and sewage, which the selected strain, SA-101, was identified as Mucor sp. with microbiological characteristics. Its milk clotting enzyme production was maximized when grown on 10g of wheat bran media added to 8ml of tap water containing 0.1M HCl for 60hrs at $30^{\circ}C$. This enzyme production was stimulated by addition of 6% lactose, 0.05% NaCl and reached a maximal level of 9810 unit/g wheat bran. The crude enzyme product could be produced effectively by salting out with ammonium sulfate fractionation and lyophilization. The ratio of milk clotting activity to proteolytic activity of crude enzyme product was lower than Hansen rennet, but resembled to Meito rennet. The optimal temperature of milk clotting activity of crude enzyme product was abound $60^{\circ}C$ on a substrate of 10% reconstituted skim milk containing 1/100M $CaCl_2$.

• Korean Journal of Food Science and Technology
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• v.3 no.2
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• pp.89-93
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• 1971

Microorganisms producing milk-clotting enzyme were isolated from 1,506 strains which were collected from soil on the various places of Korea, and from strains which were already identified. Dothiorella ribis was taken as a good strain producing milk-clotting enzyme. When it is cultured on wheat bran, the optimum experimental conditions for the production of milk-clotting enzyme were consequently obtained as follows: 1) $30{\sim}35^{\circ}C$ of temperature and 4.0 of pH. 2) $60{\sim]80%$ of cultivating water to the weight of wheat bran. 3) addition of $(NH_4)_2SO_4$ as a nitrogen source, $NaCl\;and\;KH_2PO_4$ as an inorganic salt, and 3% of sucrose as a carbon source. 4) four days for a period of cultivation.