• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.167-171
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• 2000

Analysis of Production of Thermostable Alkaline Protease using Thermoactinomyces sp. E79. Jung, Sang Won, Sung-Sik Park, Yong-Cheol Park" Tae Kwang Oh2, and Jin-Ho Seo*, Department of Food Science and Technology, Seoul National University, Suwon 441-744, Korea, 1lnterdisciplinary program [or Biochemical Engineering & Biotechnology, Seoul National Univer5it}~ Seoul 151 "7421 Koreal 2Microbial Enzyme RU, Korea Research Institute of Bioscience & Biotechnology, Po. Box 1151 Yusong, Taejon 305"6001 Korea - This research was undertaken to analyze fermentation properties of Thermoactinomyces sp. E79 for production of a thermostable alkaline protease, which is able to specifically hydrolyze defatted soybean meal (DSM) to amino acids. TIle optimum pH for cell growth and protease production was pH 6.7, Thermoactinomyces sp. E79 did not grow at pHlO Among carbon sources tested, soluble starch was the best for protease production, while glucose repressed protease production. Tryptone was found to be the best nitrogen source for cell growth and soytone was good tor protease production. Oxygen transfer rate played an important role in producing thermostable alkaline protease. Ma'<..imum values of 6.58 glL of dry cell weight and 43.0 UJmL of protease activity were obtained in a batch fermentation using a 2.5 L jar fermentor at 1.93 X 102 hr-l of volumetric oxygen transfer coeff'jcient (kLa). Addition of 200 mgIL humic acid to the growth medium resulted in 1.64 times higher protease activity and 1.77 times higher cell growth than the case without humic acid addition.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.228-234
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• 1984

A partial hydrolysis of soybean protein isolate was carried out by using pepsin and trypsin. The degree of hydrolysis was evaluated by chemical analysis, viscometric measurements and gel electrophoresis. The functional properties of the hydrolyzates such as flow behavior, emulsion properties and foaming properties were evaluated. A selective hydrolysis of 11S protein fraction by pepsin was observed from the SDS-PAG electrophoresis. The changes in the molecular weight distribution by different conditions of enzyme hydrolysis were evaluated. The changes in the intrinsic viscosity of the protein hydrolylate by reaction time were highly correlated to the contents of TCA soluble protein and 0.03 M $CaCl_2$ soluble nitrogen. The degree of hydrolysis ($DH_{TCA}$, $DH_{Ca}$) were used to evaluate the effect of enzyme treatment on the functional properties of the hydrolyzate. The apparent viscosity and emulsion capacity and stability of the protein solution decreased as DH increased, while the foaming capacity increased linearly with the increasing DH.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.147-155
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• 2016

This study presented a measure for turning by-products, released from land farming sites, into resources. The measure involved adding food by-products such as rice bran and nonfat soybean to the sludge, released from the eel farming sites, inoculating the lactic acid bacteria, Aspergillus oryzae, and Bacillus subtilis by step, fermenting them, and measuring the changed ingredients of the fermented fodder. The water content of the fermented fodder by the step of preparation was the first-step fermented product (14.6%) using the lactic acid bacteria, and the second and third-stage fermented product (33.0% and 34.0% respectively) using Aspergillus oryzae and Bacillus subtilis. The pH level was found to be 5.38 in the first-step fermented product due to the secretion of lactic acid caused by the lactic acid bacteria, and the pH level of the second and third-stage fermented products was 5.66 and 7.26, respectively, showing that the pH level increased. The phytic acid content was 0.126g/100g in the first-step fermented product, 0.004g/100g in the second-stage fermented product, and 0.093g/100g in the third-stage fermented product. The measurement of nitrogen content revealed that the amino nitrogen content was high with 1226.37mg% in the second-stage fermented product, and a little lower with 710.18mg% in the third-stage fermented product. The ammonium nitrogen content increased from 0.988mg/kg in the first-stage fermented product to 1.502mg/kg in the third-stage fermented product. Total nitrogen content increased to 2.78% in the first-stage fermented product, 4.08% in the second-stage fermented product, and 4.85% in the third-stage fermented product. As fermentation continued with the three microbes, the phytic acid decreased, and the protein decomposition rate increased. Also, due to the 3 step fermentation, the low-molecule nitrogen ingredient content increased, suggesting that the fodder was developed to offer high digestion and absorption.

• Korean Journal of Poultry Science
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• v.18 no.1
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• pp.33-42
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• 1991

In order to study effects of the 9round charcoal and organic acid on the egg production, White Leghorn strain(Hyline) layer of 113 week-old were fed control diet during a week of previous feeding and subsquent experimental diets during 12 weeks of experimental feeding . The experimental diets were the basal (control) diet composed of mainly corn-soybean meal, diet (CPB) substituted 0.5％ of ground charcoal with the defatted rice bran of the control, diet (PWV) added 0.1 mM(based on the acetic acid) of wood vinegar in the CPD and diet(PFA) added 0.1 mM (based on the acetic acid) of fermented acetic acid in the CPD. During experimental feeding period, birds (ed control, CPD and PWV diets showed similar feed intake which was shown a decreasing tendency in birds fed PFA diet as the passage of experimental feeding period. Birds fed experimental diets containing ground charcoal were tended to increase egg weight (g/egg) , while which of birds fed CPD was higher(P＜0.05) than that fed control diet. Chicks fed the control, CPD and PWV diets produced 75.9, 75.0 and 75. 9％ of egg, respectively, which were significantly(P＜0.05) higher than those of birds fed PFA. Daily egg mass(g/bird) were reached to 48.6, 49.9 and 49.5g i,1 layer fed the control, CPD and PWV diets, respectively, showing an increasing tendency in layer fed CPD and PWV compared with those of birds fed control, which were significantly (P＜0.05) higher than those of birds fed PFA . Although the effect of experimental diets on the feed efficiency (egg/feed) was not found, which was shown an increasing tendency in layer fed CPD compared with those in control diet. Compared with the incidence of cracked or shelless eggs in birds fed control diet, which were lowered to 37％ in birds fed CPD diet and 70％ in PWV-fed birds and increased to two times in birds fed PFA . The contents of cholesterol in egg was not affected by experimental diets, while birds fed CPD diet increased significantly(P＜0.05) the daily biosynthesis of egg protein and showed a trend to increase the thickness of eggshell and eggshell contents per eggs compared with that of control diet-fed birds. The results indicated that the ground charcoal powder improved the performance of layer.