• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.155-160
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• 1986

$\alpha$-Amylase gene of B. amyloliquefaciens was cloned to E. coli-yeast shuttle vector YEp-13 and expressed in E. coli. Chromosomal DNA of B. amyloliquefaciens was partially digested with Sau3Al and YEp13 plasmid was cleaved with BamH1. The hybrid plasmid, pHA28, was constructed by shotgun method and transformed to E. coli C600 and HB101. The amount of $\alpha$-amylase produced by transformants of E. coli was about 20% to 30% of that produced by B. amyloli-quefaciens. About 65% of $\alpha$-amylase produced by transformant was secreted into periplasm and the others were located in cytoplasm. $\alpha$-Amylase production was maximal when transformants were cultivated for 15hr to 20hr. As the result of agarose gel electrophoresis, pHA28 plasmid was found to be various in its size. This result suggested that pHA28 plasmid was segregated.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.213-218
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• 1986

Hybrid plasmid pEA24, shuttle vector YRp7 carrying amylase gene of Bacillus amyloliquefaciens, was transformed to yeast Saccharomyces cerevisiae, and the expression of B. amyloliquefaciens amylase gene in yeast was investigated. The frequency of transformation to S. cerevisiae DBY747 with YRp7 was increased by treatment of 40% polyethylene glycol (MW 4, 000), PH 7.0, at 3$0^{\circ}C$, and by regeneration used 2% top agar. The amount of cellular amylase activity produced by S. cerevisiae containing pEA24 was 2% of that secreted from B. amyloliquefaciens, but in case of S. cerevisiae transformant, the amylase secreted was not detected. A comparison of genetic stability of pEA24 and YRp7 plasmids in yeast was carried out by cultivation of transformants in tryptophan-supplement-medium. The pEA24 plasmid was more unstable than YRp7 in S. cerevisiae. The size of pEA24 extracted from S. cerevisiae transformants was found to be identical with that from E. coli transformants by agarose gel electrophoresis.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.209-212
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• 1986

$\alpha$-Amylase gene of Bacillus amyloliquetaciens was cloned on plasmid YEp13, S. cerevisiae-E. coli shuttle vector. Hybrid plasmid pTG17, carrying $\alpha$-amylase gene of B. amyloliquefaciens, was transformed to E. coli and the expression of it in yeast was investigated. This plasmid was unstable in E. coli and produced two minor plasmids, pTG17-1 and PTG17-2, which resulted from the segregation of it. Transformant of S. cerevisiae MC16 with pTG17-1 plasmid was not appeared on SD medium because of the Leu2 gene defection. S. cerevisiae could be transformed by the hybrid plasmid, and $\alpha$-amylase activity of the yeast transformant was detected by somogyi-Nelson method and agar diffusion method.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.464-469
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• 1991

An $\alpha$-amylase producing bacterium, strain 2B, was isolated from soil and identified to genus Bacillus. To enhance $\alpha$-amylase productivity, strain 2B was mutagenized successively with nitrosoguanidine. For an efficient selection of a-amylase hyperproducers, mutants which produced $\alpha$-amylase in the presence of glucose were isolated. The resultant mutant HG4, which was classified as constitutive and catabolite derepressed hyperproducer of a-amylase, produced about 30 folds more $\alpha$-amylase than parental strain in medium containing lactose as carbon source. The strain HG4 grew rapidly and produced enzyme in parallel with cell growth. Moreover, its cell lysis did not occur until time of maximal yield of enzyme, which was considered to be a favorable characteristic for the production and purificiation of enzyme in industrial scale. The enzymatic properties of parental strain 2B and mutant strain HG4 were almost the same. The optimal temperature and pH for enzyme reaction was $70^{\circ}C$ and pH 6.0, respectively, in 'the presence of 0.6mM $Ca^[2+}$ as an effective stabilizer.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.57-67
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• 2007

In currently, stress diseases are increased that present several sign and symptoms. Under stress condition, there are dry mouth, burning mouth syndrome, oral mucosa diseases and halitosis more frequently. Changing of salivary proportion is checked in almost patients with changing of function and structure in salivary gland. This study purpose are what effect stress does on salivary gland, and a-amylase on salivary gland. This study was resulted that 1. Under restraint stress, acinar cells are vacuolization and changing of intercellular spaces are separated, and peripheral tissues of duct are changed 2. Acinar cells were shrunk after 3 hours under restraint stress, intercellular space was separated after 6hours, peripheral tissues of duct started to change after 72 hours, and acinar cells and peripheral tissues of duct were all severely changed after 168hours. 3. In immunohistochemical study, amylase reaction was showed partially and irregularly after 3 hours, was getting little milder after 6 hours. And amylase reaction was gradually increased from the time of 12 hours after experiment up to the time of 48 hours after experiment. But after 168 hours, amylase appearance was diminished. According this result, emotional stress can change of salivary gland structure, and amylase secretion, the important digestive enzyme from salivary gland is changed and it is supposed to make digestive disorder and to make halitosis efficiency. So, we need to study about secretion of amylase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.812-815
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• 2009

The effects of processing conditions on the ${\alpha}$-amylase activity of radish were investigated at various temperatures, pHs and drying conditions. The ${\alpha}$-amylase activity of radish root was 3.1-fold higher than that of radish trunk. As the freeze-dried radish was incubated at various temperatures and pHs, ${\alpha}$-amylase activity was stably maintained at pH range of $4{\sim}7$ and temperature of $25{\sim}40^{\circ}C$. When radish was processed to kakdugi and danmooji, the residual ${\alpha}$-amylase activity was 45.39% and 19.19%, respectively. Consequently, the ${\alpha}$-amylase activity was greatly affected by processing conditions such as heat treatment and pH. It is suggested that radish should be processed at below $60^{\circ}C$ and at neutral to acidic pH condition.

• Journal of Environmental Science International
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• v.16 no.4
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• pp.409-414
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• 2007

Effects of dimethipin on ${\alpha}$-amylase activity of barley seeds were investigated. In the treatments of $1{\mu}M\;and\;10{\mu}M$ dimethipin, the indexes of germination were reduced to 17% and 24 % respectively. After seed germination, dimethipin was added to germinated seedlings and then the seedlings were kept to measure seedling length under illumination for 7 days. In control, the length of seedling was 5.7 cm, but in the treatments of $1{\mu}M$ dimethipin and $10{\mu}M$ dimethipin, seedling lengths were 5.5 cm and 1.2 cm respectively. In the relationship between dimethipin concentrations and ${\alpha}$-amylase activities, there was a linear curve. The more dimethipin was added to the seeds, the more ${\alpha}$-amylase activities were inhibited. In the treatments of $1{\mu}M$ dimethipin and $10{\mu}M$ dimethipin, ${\alpha}$-amylase activities were reduced to 33% and 71% respectively. Dimethipin also inhibited ${\alpha}$-amylase activities increased by gibberellin and the content of soluble protein. Therefore, it could be suggested that dimethipin might inhibit directly the activities of hydrolysis enzymes including ${\alpha}$-amylase or the expression of ${\alpha}$-amylase genes as germination and seedling growth were severely disturbed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.591-595
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• 1990

A promoting effect of ginseng saponin on the growth recovery rate of Saccharomyces rouxii which was treated by heat was confirmed in previous report(22). In order to deduce the promoting effect on the growth recovery of the heat stressed yeast, the effect of ginseng saponin on the activity and the heat stability of the amylase produced by Sacchirromyces rouxii were observed. The amylase showed the highst activity at 0.01％ of saponin. At this concentration, the activity increased about 23％ compared to the control. Furthermore, the ginseng saponin showed a protective effect against thermal inactivation of the amylase produced by Saccharomyces rouxii.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.290-293
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• 2003

To measure an effects of strontium on secretion of ${\alpha}$-amylase and RNase, wheat aleurone layers were isolated after the pre-incubation in a solution with or without 10 mM $SrCl_2$ or $CaCl_2$ for 3 days at $25^{\circ}C$ in the dark under aseptic conditions. The secretion of ${\alpha}$-amylase reached a maximum at 72 h after incubation. $Sr^{2+}$ induced more effectively secretion of ${\alpha}$-amylase than $Ca^{2+}$. The ${\alpha}$-amylase secretions by $Sr^{2+}$ or $Ca^{2+}$ ware about $2 (Ca^{2+})$ to $2.5 (Sr^{2+})$ fold higher than it without divalent ions, When aleurone layers were incubated without divalent ions, however, the ${\alpha}$-amylase was remarkably retained in the tissues. Total ${\alpha}$-amylase synthesis (ie. tissues + media) was slightly lowered by 10mM $SrCl_2$ addition. It seemed that the RNase secretion begins at 18 h after incubation. This meaned that the RNase secretion may process slower than ${\alpha}$-amylasee secretion. $Ca^{2+}$ effect on RNase secretion is stronger than $Sr^{2+}$ unlikely to ${\alpha}$-amylase. The secretion process is likely to be suddenly induced between 72 hand 96 h. These results suggested that the secretion was enhanced after the accumulation in aleurone layers.

• The Korean Journal of Food And Nutrition
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• v.6 no.4
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• pp.294-300
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• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of saccharogenic amylase during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Tikju and Yakju in Korea. The optimum cultural temperature for the production of saccharogenic amylase by this mold was 36$^{\circ}C$, and at this temperature it needed 40 hours of cultivation for maximum production of this enzyme. It was favorable for high production of both organic acid and saccharogenic amylase to shift the cultural temperature form initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. The production of saccharogenic amylase was low when the water content of steamed rice was below 35%, but its production was high at 40~60% of water content. When the quantity of conidial inoculation was too small, the production of saccharogenic amylase was low in initial phase, but it was retrived after 40 hours of cultivation. When koji-thickness was over 3cm, the production of saccharogenic amylase was markedly restricted. The saccharogenic amylase of this koji was stable at pH 2~7, and showed high activity at pH 2~5.