• Applied Biological Chemistry
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• v.30 no.3
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• pp.250-257
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• 1987

The most active strain for the amylase activity from the native Youngkwang koji, was isolated and identified as Aspergjllus awamori. The optimal conditions for the production of ${\alpha}-amylase$ and glucoamylase were investigated and the properties of these enzymes were also examined. Maximum yields of ${\alpha}-amylase$ and glucoamylase were obtained at $30^{\circ}C$, pH 5.0 for days. The production of these two enzymes were increased with the addition of maltose, urea, $K_2HPO_4$, $MgSO_4{\cdot}7H_2O$, and $CaCl_2{\cdot}2H_2O$. The activities of these enzymes were maximized at $50^{\circ}C$, $pH\;5{\sim}6$. The heat stabilites of ${\alpha}-amylase$ and glucoamylase were maintained at $50^{\circ}C$ for 20min and 40min, respectively. Also, the addtion of $MgSO_4{\cdot}7H_2O$, $K_2HPO_4$, and $CaCl_2{\cdot}2H_2O$ salt increased the heat stabilities of these enzymes.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.545-551
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• 2008

When cultivated aerobically, Aspergillus niger hyphae produced extracellular glucoamylase, which catalyzes the saccharification of unliquified potato starch into glucose, but not when grown under anaerobic conditions. The $K_m\;and\;V_{max}$ of the extracellular glucoamylase were 652.3 mg/l of starch and 253.3 mg/l/min of glucose, respectively. In mixed culture of A. niger and Saccharomyces cerevisiae, oxygen had a negative influence on the alcohol fermentation of yeast, but activated fungal growth. Therefore, oxygen is a critical factor for ethanol production in the mixed culture, and its generation through electrolysis of water in an electrochemical bioreactor needs to be optimized for ethanol production from starch by coculture of fungal hyphae and yeast cells. By applying pulsed electric fields (PEF) into the electrochemical bioreactor, ethanol production from starch improved significantly: Ethanol produced from 50 g/l potato starch by a mixed culture of A. niger and S. cerevisiae was about 5 g/l in a conventional bioreactor, but was 9 g/l in 5 volts of PEF and about 19 g/l in 4 volts of PEF for 5 days.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.1055-1060
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• 2012

In order to produce Hongkuk-ju, the production and characterization of Hongkuk (Monascus red koji) by Monascus anka KCTC 6121 were investigated. The optimum cultural conditions for the production of enzyme (${\alpha}$-amylase and glucoamylase) and pigment (yellow and red) from this strain on solid culture (steamed rice) were examined. The results showed that the production of ${\alpha}$-amylase and glucoamylase reached the highest for 9 days and 8 days, respectively. Since then, the productions decreased slightly. The production of yellow and red pigments reached the highest for 8 days, decreasing slightly soon after. The optimal content of the initial moisture equally presented 30% in the enzyme and pigment production. After that, the enzyme production decreased slowly, whereas pigment production decreased sharply. The optimal temperature of the culture also showed $30^{\circ}C$ in the production of enzyme and pigment. It was found that the initial inoculum size in enzyme and pigment production was 10% and 20%, respectively. Under these optimal conditions, the production of monacolin K and citrinin was 74.35 mg/kg and 5 mg/kg for 12 days, respectively.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.63-70
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• 1997

The extracts from Agastache rugosa O. Kuntze, their chloroform and hexane fractions, and estragole identified from hexane fraction were tested to investigate the effects on the growth and metabolic activities of several true fungi. The fungi used were: Aspergillus oryzae KFCC 890, Aspergillus niger KCCM 11240, Saccharomyces cerevisiae IAM 4597, Saccharomyces ellipsoideus PNU 2215. The growth of S. Cerevisiae by treatment of water extract(1%), hexane fraction (0.05%), and estragole (0.05%) were inhibited 93%, 50%, and 33% respectively, and S. ellipsoideus was also inhibited markedly with delaying the alg phase maximum 12 hrs. The growth of A. oryzae was inhibited by treatment of extracts and fractions. The echanol production by S. cerevisiae was increased more than two times in the highest value around 42 hrs incubation by water extract, but chloroform fraction inhibited its production. The glucoamylase actibities by A. niger were strongly inhibited by hexane and chloroform fractions (0.05%). The invertase activity by S. cerevisiae using estragole (0.05%) reached to 57.5% of control group. S. cerevisiae treated with the estragole was damaged the cell wall and cell membrane, leaked the protoplasm, and observed broken pieces of cell.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.546-552
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• 1992

Ethanol-tolerant strain, S. eerevisiae BUI a26 ($alc^r thr^-$) and gJucoamylase-producing strain, S diastatieus AI5a6 (STA+ hom-) were prepared by means of genetic manipulation, Protoplast fusion was carried out to introduce STA gene from AI5a6 strain to BUla26 strain, Protoplast formation was shown at 0,8 M sorbitol and 200 Jig/ml to 400 Jig/ml zymolyase treatment for 2 hours incubation, Fusion frequency was $ 3.25 {\times} 10^{-3}$ to the regenerated protoplast number using PEG 6000 for 90 min incubation. The excellent fusants with genotype of STA- $alc^r thr^-$ hom+/STA+ ($alc^s thr^+$ hom- (2n), F7 and FIO, were selected by ethanol-tolerant, ethanol fermentation, and glucoamylase production tests, Glucoamylase production of AI5a6 showed 2,7 units, but 4.2 or 8.4 units for F7 or FIO fusant at $30^{\circ}C$, Ethanol fermentation from 32% glucose by BUla26 was 14,0%(v/v) in fermentaion medium for 5 days incubation, but 14.5% or 15,0% for F7 or FIO strain, respectively. Ethanol fermentation from 5% starch was 2,0% by F7, or 1.8% by FIO strain in fermentation medium for 5 days fermentation.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.98-104
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• 1998

As an efffort ot construct LAB (latice acid bacteria), capable of utilizing starch as fermentation substrate without the aid of externally supplied enzymes, plasmid vectors containing the amyL($\alpha$-amylase/pullulansase gene) from Clostridium thermophydrosulfuricum, and glucoamylase cDNA from Asperigillus shirousamii were constructed and introduced itno E. coli and L. lactis. For expression in procaryotes , 1.9kb glucoamylase cDNA encoding the mature form of enzyme was PCR amplified and translationaly fused to a PCR amplified 260 bp fragment containing the promotor and secretion signals of amyl in the same reading frame. The production of $\alpha$-amylase, Apu, and glucoamlase in E. coli and L. lactis was confirmed by enzyme assay and zymography . Enzymeswere detected in both cellpellets and supernatants, indicating theworking of scretion signals in heterologous hosts. The efficiencies of secretion were varibale depending on the gene and host. The highest $\alpha$- amylase acitivity observed was 1.1 units and most activiity was detected from thecell pellets. The degree of gene expression in both hosts and the effect on the growth of hosts were examined.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.609-614
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• 2010

In the present study, bioethanol was produced using batch style reactor from food wastes which has organic characteristics. Pretreatment was required to reduce its particle size and produce fermentable sugar. Two different enzymes such as carbohydrase and gulcoamylase were tested for saccharification of food waste. The efficiency of carbohydrase saccharification (0.63 g/g-TS) has shown higher than glucoamylase saccharification(0.42 g/g-TS). Saccharomyces cerevisiae produced bioethanol via separate hydrolysis & fermentation (SHF) method and simultaneous saccharification fermentation (SSF) method. The production amount of bioethanol was 0.27 g/$L{\cdot}hr$ for SHF and 0.44 g/$L{\cdot}hr$ for SSF.

• 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.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.54-54
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• 2001

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.858-862
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• 2008

The Simultaneous Saccharification and Fermentation(SSF) of ethanol production from potato starch studied with respect to growth pH, temperature, substrate concentration. The glucoamylase and Saccharomyceses cerevisiae have a capacity to carry out a single stage SSF process for ethanol production. The characteristics, termed as starch hydrolysis, accumulation of glucose, ethanol production and biomass formation, were affected with variation in pH, temperature and starch concentration. The maximum ethanol concentration of 12.9g/l was obtained using a starch concentration 30g/l, which represent an ethanol yield of 86%. The optimum conditions for the maximum ethanol yield were found to be a temperature of 38, pH of 4.0 and fermentation time of 18hr. Thus by using the control composite design, it is possible to determine the accurate values of the fermentation parameters where maximum production of ethanol occurs.