• Journal of Microbiology
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• v.43 no.6
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• pp.561-568
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• 2005

A newly-isolated thermophilic strain of the zygomycete fungus Rhizomucor pusillus 13.36 produced highly active dextrinogenic and saccharogenic enzymes. Cassava pulp was a good alternative substrate for amylase production. Dextrinogenic and saccharogenic amylases exhibited optimum activities at a pH of 4.0-4.5 and 5.0 respectively and at a temperature of $75^{\circ}C$. The enzymes were highly thermostable, with no detectable loss of saccharogenic or dextrinogenic activity after 1 hand 6 h at $60^{\circ}C$, respectively. The saccharogenic activity was inhibited by $Ca^{2+}$ while the dextrinogenic was indifferent to this ion. Both activities were inhibited by $Fe^{2+}\;and\;Cu^{2+}$ Hydrolysis of soluble starch by the crude enzyme yielded $66\%$ glucose, $19.5\%$ maltose, $7.7\%$ maltotriose and $6.6\%$ oligosaccharides.

• Korean Journal of Microbiology
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• v.29 no.1
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• pp.56-62
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• 1991

Extremely halophilic bacteria isolated from salterns at Mado, Kyunggido, Korea, were identified and investigated on their salt requirements. The results have shown that six strains were identified to be belonged to the genus Halobacterium and three strains identified as the fenus Halococcus. Among them, the optimal NaCl concentration for growth of Halobacterium sp. EH10 was at 4.2M and no growth occurs below 2.0M NaCl. The strain, EH10, is nonmotile and showed acid production from glucose, fructose and maltose while H. salinarum is motile and does not produce acid from any carbohydrates. On the other hand, the strain EH10 does not utilize readily glucose while a number of sugars are readily utilized for growth with acid production by H. saccharovorum. Thus, the isolate, EH10, was classified into the genus Halobacterium and could be a novel species of the genus by its main morphological and physiological features including G+C content. The optimal temperature for growth of the isolate, EH10, was 50.deg.C. But this strain did not grow when NaCl was replaced with KCl.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.557-562
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• 2002

Physiological characteristics such as specific productivity, morphology of Streptomyces cells Immobilized on celite beads, and operational stability at different dilution rates were investigated in continuous immobilized-cell cultures for the production of kasugamycin. At a dilution rate (D) of 0.05 $h^{-1}$, a relatively high specific productivity was attained and the loss of cell-loaded beads was negligible. At D=0.1 $h^{-1}$, a higher specific productivity and cell concentration could be obtained, resulting in a significantly improved volumetric kasugamycin productivity. However, no stable operation could be maintained due to a significant loss of cell-loaded beads from the reactor that was caused by their fluffy morphology developed in the later stage. At D=0.2 $h^{-1}$, the production of kasugamycin and cell growth were observed to be severely inhibited by the high concentration of residual maltose.

• YAKHAK HOEJI
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• v.33 no.6
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• pp.365-371
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• 1989

Microbiological conversion of sterols to 17-ketosteroids has been recognized as a source for commercial preparation of steroidal drugs. In order to develop bacterial strains and process with Brevibacterium lipolyticum IAM 1398 capable of converting cholesterol to 1,4-Androstadiene-3,17-dione (ADD) at about 27% yield, we studied on strain improvement, fermentation condition and whole cell immobilization. By using UV and/or NTG as mutagens, a mutant to convert cholesterol to ADD with higher yield than 60% was selected. Better production of ADD was manifested in the case of maltose used as a supplemental carbon source, and yeast extract or soytone as a nitrogen source. Addition of tween 80 (0.05%) as a surfactant beneficial for increasing the productivity. The optimal initial pH of the medium was 6.5 and optimal culture temperature was $30^{\circ}C$. Whole cell immobilization by using carrageenan, agar, alginate and acrylamide was carried out and the activity of conversion was tested. In the case of carrageenan and agar, immobilized cells were active for at least two cycles of fermentation.

• Mycobiology
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• v.37 no.2
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• pp.114-120
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• 2009

Streptomyces albidoflavus C247 was isolated from the soil of the Gyeongsan golf course in Korea. Physiological, biochemical and 16S rDNA gene sequence analysis strongly suggested that the isolate belonged to Streptomyces albidoflavus. Preliminary screening revealed that the isolate was active against fungi and bacteria. Self-directing optimization was employed to determine the best combination of parameters such as carbon and nitrogen source, pH and temperature. Nutritional and culture conditions for the production of antibiotics by this organism under shake-flask conditions were also optimized. Maltose (5%) and soytone (5%) were found to be the best carbon and nitrogen sources for the production of antibiotics by S. albidoflavus C247. Additionally, 62.89% mycelial growth inhibition was achieved when the organism was cultured at $30^{\circ}C$ and pH 6.5. Ethyl acetate (EtOAc) was the best extraction solvent for the isolation of the antibiotics, and 100 ${mu}$/ml of EtOAc extract was found to inhibit 60.27% of the mycelial growth of Rhizoctonia solani AG2-2(IV) when the poison plate diffusion method was conducted.

• KSBB Journal
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• v.13 no.4
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• pp.343-351
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• 1998

About 75 strains which utilize cholesterol as sole carbon and energy source were isolated from 10 samples of Kimchi and 18 samples of fermented fish food (2 Ojingo-jeots, salt-fermented squid ; 5 Changran-jeots, salt-fermented pollack tripe ; 5 Myungran-jeots, salt-fermented Alaska pollack roe ; 3 Gajami-sikhae-jeots, fermented flat fish ; 2 Gul-jeots, salt-fermented oyster ; a Juneo-jeots, salt-fermented shad). Among them tested, the 3T6-5Mj strain isolated from Changran-jeot showed the highest activity on cholesterol degradation. The optimal composition of medium for the producing cholesterol degradation enzyme by 3T6-5Mj strain was 1.0 g/L NH4NO3, 1.0 g/L K2HPO4, 0.1 g/L MgSO4.7H2O, 1.0 g/L FeSO4.7H2O, 1 g/L NaCl, 5 g/L Trypton, 1 g/L Cholesterol, and 5 g/L Maltose at 30$^{\circ}C$, pH 7.5, and the enzyme production reached a maximum level at 140 hours of cultivation.

• Food Science and Preservation
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• v.6 no.1
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• pp.87-91
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• 1999

In an attempt to test experimental condition of preparing grape powder, grapes having less commercial value was used and tried. With drying method, spray and freeze drying were satisfactory to produce power. Moisture content and odor retention were better by the latter method. Three grape strains stored for 40 days contained more odors than those stored for 5 days. Maltose 90% plus dextrin 10% was suitable for drying support. To increase odror sense, citric acid and vitamin C can be added up to 0.1 and 0.2%, respectively. Considering these conditions, grape complex powder prapared from grape powder 20% comprising drying support, glucose 79.7%, citric acid 0.1%, vitamin C 0.2% with freeze drying was the best by overall evaluation including sensory test. When campbell and neomuscut were mixed by 15:5 or 10:10, sensory evaluation was also ameliorated.

• Korean Journal of Food Science and Technology
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• v.10 no.4
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• pp.423-430
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• 1978

Since 1950 there has been a dramatic progress in rationalization of the production of sweet potato and potato starch in Japan. This enabled dextrose industry by enzymatic process to develop rapidly due to the success of enzymatic liquefaction and saccharification. Isomerization of glucose to fructose has been studied, and the immobilization of isomerases prompted its products on industrial scale in 1970. Another advance is the development of effective methods of producing high purity maltose. A malto-hexaose forming amylase was discovered in 1971 and attempts are being made for its pharmaceutical utilization. Saccharification of cellulose by cellulase has been studied. Conversion of starch to other polysaccharides is another example for the numerous Japanese activities.

• The Korean Journal of Food And Nutrition
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• v.12 no.2
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• pp.170-176
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• 1999

Optimum preparation conditions of Korean traditional sweet rice drink 'malt-Sikye' were 1hour of rice soaking time 30min of malt extraction time 60$^{\circ}C$ of malt extraction tem-perature 60$^{\circ}C$ of saccharification temperature 1hour of agitation interval 5hour of saccharification time 5.5 of pH 4% of malt concentration and 20% of rice content. The malt-Sikhy contained to 17.1% of total sugar 11.2% of reducing sugar o.34mg/ml of protein and 4.7${\mu}$mol/ml of amino acid. The most abundant sugar found in malt-Sikhye was maltose. The commercial amylolytic enzymes were not effec-tive in preparation malt-Sikye.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.513-518
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• 1996

In order to investigate the characteristics of alcohol fermentation by Saccharomyces cerevisiae, compositions and free sugar content of dried riped pumpkin powder were determined. The proximate compositions of ripe pumpkin powder were as follows: moisture 11.98%, total sugar 62.18%(dried weight basis 70.64%), protein 13.38%, lipid 0.85%, fiber 7.07% and ash 4.54%. The compositions of free sugar in well ripe pumpkin were: glucese 85.36mg/g, fructose 40.68mg/g, sucrose 68.25mg/g, lactose 18.60mg/g and maltose 3.82mg/g. The optimum conditions for alcohol fermentation by S. cerevisiae were as follows; incubation temperature of 3$0^{\circ}C$, initial pH of 6.0, ripe pumpkin powder concentration of 10% and cells inoculation of 1.3$\times$$10^{6}$ cells/ml liquid medium. Ethanol production under the optimum conditions was 5.95g/100g in liquid medium containing 10% ripe pumpkin powder after 4 days incubation.