• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.99-107
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• 1993

Two strains (No. 26 and 143) of bacteria which secrete both pectinase and raw-starch-digesting amylase simultaneously, were isolated from various domestic soil samples. The two bacteria were identified as Pasteurella ureae judging by their morphological and physiological characteristics. The optimal culture conditions for the production of raw-starch-digesting enzyme by the Pasteurella ureae 26 were using $NH_4NO_3$ as the nitrogen source at $37^{\circ}C$ with the pH of 7.5, and 15 of C/N ratio. Since the enzyme was produced only when raw or soluble starch was used as a carbon source, but not when glucose or other sugars was used, the enzyme was considered to be an inducible enzyme by starch. Thin layer chromatography of the hydrolyzed product of starch by the raw-starch-digesting enzyme of the strain No. 26 showed that glucose, maltose and other oligosaccharides were present in the hydrolyzates, and therefore the enzyme seemed to be ${\alpha}-amylase$. The enzyme had adsorbability onto raw com starch in the pH range of 3 to 9.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.509.1-509
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• 1986

Recent advances in recombinant DNA techniques have provided a tool for breeding of microorganisms of hyper production. Enzyme production by cloned microorganism has some advantages. They are ⅰ) Enzymes can be produced by a microorganism easily cultured ⅱ) Hyper production. ⅲ) In some cases, such as thermophilic enzyme gene is cloned in a mesophilic bacteria, the enzyme purification procedure can be simplified. One example, production of thermophilic ${\beta}$-galactosidase in B. subtilis will be presented. Bacillus stearothermophilus IAM 11001 produced three ${\beta}$-galactosidases, ${\beta}$-galactosidase I, II and III (${\beta}$-gal-I, II and III). By connecting restriction fragments of the chromosomal DNA to plasmid vector, followed by transformation of Escherichia coli, two ${\beta}$-galactosidase genes (bgaA and bgaB) located close to each other on the chromosome were cloned.

• Journal of Microbiology and Biotechnology
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• v.21 no.5
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• pp.470-476
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• 2011

A potent fungus for amylase production, Chrysosporium asperatum, was isolated from among 30 different cultures obtained from wood samples collected in the Junagadh forest, India. All of the isolated cultures were screened for their ability to produce amylase by submerged fermentation. Among the selected cultures, C. asperatum (Class Euascomycetes; Onygenales; Onygenaceae) gave maximum amylase production. In all of the different media tested, potato starch was found to be a good substrate for production of amylase enzyme at $30^{\circ}C$ and pH 5.0. Production of enzyme reached the maximum when a combination of starch and 2% xylose, and organic nitrogen (1% yeast extract) and ammonium sulfate were used as carbon and nitrogen sources, respectively. There was no significant effect of metal ions on enzyme activity. The enzyme was relatively stable at $30^{\circ}C$ for 20 min, and no inhibitory effect of $Ca^{+2}$ ions on amylase production was observed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.976-980
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• 2003

A strain of potential producer of fibrinolytic enzyme was isolated from Korean fermented food. The isolated bacterium was identified and named as Bacillus brevis KJ-23. The optimal condition of the medium for the production of fibrinolytic enzyme from Bacillus brevis KJ-23 was nutrient broth with 0.5% D-ribose, 0.5% malt extract and 0.3% $K_2$HPO$_4$. The optimum pH, temperature and fermentation time for the enzyme production were pH 7.0, 3$0^{\circ}C$ and 24 hr, respectively.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1084-1091
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• 2013

In this paper, two statistical methods were applied to optimize medium components to improve the production of the milk-clotting enzyme by Bacillus amyloliquefaciens D4. First, wheat bran juice, skim milk powder, and $Na_2HPO_4$ were shown to have significant effects on D4 enzyme production using the Plackett-Burman experimental design. Subsequently, an optimal medium was obtained using the Box-Behnken method, which consisted of 3.31 g/l of skim milk powder, 5.0 g/l of sucrose, 0.1 g/l of $FeSO_4{\cdot}7H_2O$, 0.1 g/l of $MgSO_4{\cdot}7H_2O$, 0.1 g/l of $MnSO_4{\cdot}2H_2O$, 0.1 g/l of $ZnSO_4{\cdot}7H_2O$, 1.52 g/l of $Na_2HPO_4$, and 172.45 g/l of wheat bran juice. With this optimal medium, the milk-clotting enzyme production was remarkably enhanced. The milk-clotting enzyme activity reached 3,326.7 SU/ml after incubation of 48 h, which was 1.76-fold higher than that of the basic medium, showing that the Plackett-Burman design and Box-Behnken response surface method are effective to optimize medium components, and B. amyloliquefaciens D4 possessed a high rennet-producing capacity in the optimal medium.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.15-21
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• 1983

This experiment was carried out to optimize the condition for the enzyme production by selected strain in the basal medium, to purify the enzyme and to characterize the purified enzyme. The results obtained were as follows. 1. The optimal conditions for the $\beta$-galactosidase production were initial pH 7.0 and temperature $65^{\circ}C$. 2. Enzyme was induced by the addition of lactose and galactose, and it was intracellular enzyme. 3. The purified enzyme was obtained with the increased level of activity approximately 28.5 folds as compared with crude enzyme and the yield of 15.2% by means of DEAE-Cellulose column chromatography, Sephadex G-150 gel filtration 4. $\beta$-galactosidase from final step of purification showed a sing1e protein band on polyacrylamide gel disc electrophoresis. 5. The optimal temperature and pH of the purified enzyme were $65^{\circ}C$, pH 6.5 for the hydrolysis of lactose.

• BMB Reports
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• v.35 no.6
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• pp.568-575
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• 2002

An $\alpha$-amylase (EC 3.2.1.1) was purified that catalyses the production of a high level of maltose from starch without the attendant production of glucose. The enzyme was produced extracellularly by thermophilic Streptomyces sp. that was isolated from Thailand's soil. Purification was achieved by alcohol precipiation, DEAE-Cellulose, and Gel filtration chromatographies. The purified enzyme exhibited maximum activity at pH 6-7 and $60^{\circ}C$. It had a relative molecular mass of 45 kDa, as determined by SDS-PAGE. The hydrolysis products from starch had $\alpha$-anomeric forms, as determined by $^1H$-NMR. This maltose-forming $\alpha$-amylase completely hydrolyzed the soluble starch to produce a high level of maltose, representing up to 90%. It hydrolyzed maltotetrose and maltotriose to primarily produce maltose (82% and 62%, repectively) without the attendant production of glucose. The high maltose level as a final end-product from starch and maltooligosaccharides, and the unique action pattern of this enzyme, indicate an unusual maltose-forming system. After the addition of the enzyme in the bread-baking process, the bread's volume increased and kept its softness longer than when the bread had no enzyme.

• Journal of Life Science
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• v.8 no.3
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• pp.333-338
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• 1998

Productivity of alkaline proteinase from Yarrowia lipolytica 504D was investigated. For the production fo the enzyme, hemoglobin was the best nitogen source, however, casein and skim milk were also good. All carbon sources inhibited strongly the producitivity of the enzyme. Yeast extract increased the productivity of the enzyme to 220%, but almost mineral salts except monovalant ions decreased it. Based on these results, optimal medium was composed of 1.2% casein, 0.2% glucose, 0.16% yeast extract, and 0.1% ammonium sulfate. the best condition for the production of the enzyme was observed at pH 9 and $20^{\circ}C$ for 42 hours.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.187-194
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• 2000

An actinomycetes strain, T-2, which produces transglutaminase (EC 2.3.2.13), was isolated from soil and identified as belonging to the Actinomadura sp., based on taxonomc studies. The conditions for the transglutaminase production and its enzymatic properties were investigated. The optimum components for the transglutaminase production were 2% glucose, 1% polypeptone and soytone, and 0.1% MnCl2. The optimum pH and temperature of the enzyme reaction were pH 8.0 and $45^{\circ}C$, respectively. The enzyme was stable within the pH range of 5.0-9.0 and $30^{\circ}C-45^{\circ}C$. The novel enzyme required no calcium ions for its activity. This enzyme polymerized various proteins such as casien, soy protein, hemoglobin, egg white, gelatin, and soybean milk.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1010-1016
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• 1999

Protease related mold was isolated and selected as a starter culture for commercial production of meju. Isolated microorganism was identified as Syncephalastrum racemosum PDA 132 2. To obtain basic data about protease for production of soybean peptides and application of the strain in meju fermentation, we extrated and purified protease and charateristics of the enzyme were investigated. The optimum condition for the production of enzyme was pH 4.0, 30oC, 5 days. The protease was purified 19.7 folds by gel filtration and ion exchange chromatography and specific activity was 12.4unit/mg. The purified enzyme was 34kDa in size, thiol protease(100% inhibited by PCMB), and was acidic protease(stable between pH 2.0~5.0). Vmax of the enzyme was 2.14 g/min which was lower(1/50) than that of by Asp. wentti and B. subtilis.