• Applied Biological Chemistry
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• v.34 no.1
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• pp.1-7
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• 1991

Optimum conditions for hydrolysis of sunflower seed by pepsin and for plastein formation by pepsin were determined. The optimum conditions for hydrolysis of sunflower seed were pH 1.5, $45^{\circ}C$, enzyme concentration 2%, substrate concentration 2%, and hydrolysis time 24hr. The optimum conditions for sunflower seed-plastein formation were 50% substrate, pH 4.5, $50^{\circ}C$, 0.25% pepsin and 18hrs reaction time. To verify plastein fromation from concentrated prptic hydrolysate of sunflower seed, thin layer chromatography was performed. The TLC pattern of concentrated peptic hydrolysate of sunflower seed was different from that of its plastein. The TLC pattern of concentrated peptic bydrolysate of sunflower seed and at of its plastein indicated that plastein was different material from the hydrolysate.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.107-117
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• 2005

The objective of this study was to investigate the proper operation conditions of fenton oxidation such as initial pH, $H_2O_2/Fe^{2+}$ ratio, $H_2O_2/Fe^{2+}$ dosage amount, and neutralizing agent for pretreatment of the livestock wastewater. Fenton oxidation reagents were reacted with the livestock wastewater for 2 hours at 120 rpm and the settling was performed for 2 hours using jar-tester apparatus under the different experimental conditions. And then the supernatant was sampled and measured for the residual $H_2O_2$, $COD_{Cr}$, and SS. The results are as follows; optimum initial pH=4, optimum $H_2O_2/Fe^{2+}$ ratio=10:1, optimum $H_2O_2/Fe^{2+}$ dosage amount=5,000/500 mg/L and $Ca(OH)_2$ as proper neutralizing agent. The removal efficiency of $COD_{Cr}$ and SS were 43% and 84% under those optimal fenton oxidation conditions.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.317-321
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• 1997

The effect of ammonium ion concentration on the production of demethyl- chlortetracycline (DMCT) by a DMCT overproducing mutant, Streptomyces aureofaciens 27VR, and the optimal control of pH were studied. The optimum levels of pH control were 6.5-6.6 for 80-120 hr, 6.4- 6.5 for 121-150hr and 6.3-6.4 for 151-190hr. The optimum level of ammonium ion concentration during the pH control was lower than 20 mg%. Under the optimized culture condition, it was possible to produce DMCT with an 18% increase in productivity compared to that of standard culture condition in 190hrs of the fermentor operation.

• YAKHAK HOEJI
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• v.36 no.4
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• pp.390-396
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• 1992

Streptomyces minoensis DMCJ-144 isolated from soil produces the ${\alpha}-amylase$ inhibitor. Optimum culture conditions for ${\alpha}-amylase$ inhibitor production of the strain were determined in this experiment. The optimum composition of the culture medium was studied by supplementing various carbon sources, nitrogen sources, vitamins, and metal salts to the basal medium containing 1% glucose, 0.1% asparagine, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $K_2HPO_4$, 0.005% NaCl. Other culture conditions such as the culture temperature, initial pH of the medium, aeration, and culture time were also investigated. When the strain was cultured in a 100 ml flask containing 20 ml of 2% glucose, 0.5% beef extract, 0.0002% riboflavin, 0.0002% thiamine HCI, 0.01% $ZnCl_2$, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $CuSO_4{\cdot}5H_2O$, 0.005% NaCl, pH 7.2, 180 rpm at $30^{\circ}C$, the maximum production of the ${\alpha}-amylase$ inhibitor was observed after 5 days of the cultivation.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.463-474
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• 2010

In this study, chemical coagulation conditions for treating combined sewer overflow(CSO) occurred during rainy season were evaluated by jar tests with aluminum sulfate[$Al_2(SO_4)_3{\cdot}17H_2O$] and ferric chloride[$FeCl_3{\cdot}6H_2O$]. The raw domestic sewage sampled from the primary sedimentation tank at a local sewage treatment plant was filtered through $150{\mu}m$ sieve before using. Point of zero charge(PZC) for various dose of aluminum sulfate occurred at pH 5.8-6.5, while for ferric chloride occurred at pH 5.3-6.0 in term of streaming current(SC) values. Charge neutralization ability of aluminum sulfate was bigger than that of ferric chloride. Optimum pH and dose of aluminum sulfate and ferric chloride were 6.2, 0.438mM and 5.8, 0.925mM, respectively. Removal efficiencies of TCOD, turbidity, SS and TP were 75, 97, 95, 96% with aluminum sulfate and 74, 96, 98, 99% with ferric chloride at their optimum coagulation conditions. More efficient removal of SS, TP and small particles was possible with ferric chloride at optimum coagulation conditions. Both SC values and COD removal started to increase where soluble phosphorus was completely removed.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.73-80
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• 1998

Peroxidase has been isolated to apparent homogeneity from earthworm, Lumbricus rubellus, using ammonium sulfate fractionation, Sephacryl S-2000 gel filtration, CM-cellulose cation exchange chromatography and native-PAGE elution. Some of its enzymatic characteristics were examined. The optimum pH for gruaiacol oxidation of earthworm peroxidase was determined to be 6.0, and the $K_{m}$ values against guaiacol and $H_2O_2$ were 1.25 mM and 3.4mM, respectively. When various compounds were tested as the possible substrates of the enzyme, o-dianisidine was used as the substrate. However, earthworm peroxidase could not oxidize esculetin and ferulic acid as substrates, suggesting the different characteristics of the enzyme from plant peroxidases. The optimum pH for veratryl alcohol and $H_2O_2$ oxidation was determined to be 2.5 when lignin peroxidation activity was examined. The $K_{m}$ values for veratryl alcohol and $H_2O_2$ were 0.02 mM and 0.13 mM, respectively. Furthermore, the earthworm peroxidase could oxidize phenoxyherbicides such as 2,4-D, 2,4-DP and MCPA as substrates. The optimum pHs for 2,4-D, 2,4-DP and MCPA were determined to be 4.0, 2.0 and 2.0, respectively. The most available substrate was 2,4-DP, followed by MCPA and 2,4-D when their peroxidation activities were compared.

• Journal of Pharmaceutical Investigation
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• v.19 no.1
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• pp.9-14
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• 1989

In order to study the protease from Agaricus bisporus (Lange), the crude protease preparation was separated by fractionation of mushroom extracts with ammonium sulfate. It was found that extracts from Agaricus bisporus (Lange) Sing. contained protease. The optimum pH of the enzyme was 6.0, and the pH range at which the enzyme was stable was 4.0 to 7.0. The optimum temperature at which the enzyme showed the highest proteolytic activity was $50^{\circ}C$, while the enzyme was instantly inactivated at about $60^{\circ}C$. The enzyme activity was inhibited by $Ag^+$, $Hg^{2+}$, $Cu^{2+}$, $Ba^{2+}$, $Fe^{3+}$, $Co^{2+}$, $Ca^{2+}$, $Pb^{2+}$, $Mg^{2+}$ and $Mn^{2+}$. The $K_m$ value was 0.32 mM with Hammarsten casein.

• The Korean Journal of Mycology
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• v.17 no.3
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• pp.145-148
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• 1989

An acid-stable ${\alpha}-amylase$ produced by Aspergillus niger K-25 strain was purified by fractional precipitation with ammonium sulfate, ethacridine and acetone. The final preparation was homogeneous in cellulose acetate electrophoresis. The enzyme retained 91 % of its oringinal activity at pH 3.0, 8.7% at pH 2.4. The optimum pH of the enzyme was around pH 4. The purified-enzyme with optimum temperature of $40^{\circ}C$ was more heat-stable than the commercial product. The enzyme retained 80% of its original activity when heated to $60^{\circ}C$ for 30 minutes while the commercial amylase lost its acitivity completely within 30 minutes at $50^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.15 no.3
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• pp.215-219
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• 2002

Growth characteristics of sourdough lactic acid bacteria was investigated to obtain basic informations for sourdough starter. The optimum temperature and pH on bacterial growth and lactic acid production of Lactobacillus brevis UC-22 in sourdough broth were 35'E and around pH 5.5, respectively. And the optimum concentrations of the carbohydrate sources added to the broths was 2% maltose. The acidity significantly increased during growth by Lactobacillus brevis UC-22 fur 18 hours while pH significantly decreased during growth.

• KSBB Journal
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• v.9 no.2
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• pp.127-132
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• 1994

A new method of fructooligosaccharides production was investigated by an amyloglucosidase using sucrose as a substrate. Optimum reaction conditions were as follows: sucrose concentration, 700g/$\ell$; pH 5.5; temperature, $55^{\circ}C$; enzyme dosage, 48 units per gram sucrose. At the optimized reaction conditions, 41.5% of fructooligosaccharides were produced after 25 hours. A hydrolyzing activity was stronger than transfructosylting activity at low sucrose concentrations, resulting in low production rate of fructooligosaccharides. The optimum pH and temperature in both transfructosylating(pH 5.5, $60^{\circ}C$) and hydrolyzing activity(pH$4.75^{\circ}C$)were significantly different from each other. The amyloglucosidase also utilized fructooligosaccharides as a substrate and glucose seemed to be an inhibitor.