• The Korean Journal of Mycology
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• v.20 no.1
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• pp.77-82
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• 1992

Researches were carried out to find the optimal conditions of carbon sources, nitrogen sources and pH for the maximum production of sporophore of Lentinus edodes. Dextrin, aspartic acid and pH 4.0 were the best conditions for yield of sporophore by using replacement culture technique. The production of sporophore was stimulated by addition of 0.8% triacylglycerol in NS medium. Coffee waste was chosen for the best substrate among the poplar, oak, white aspen saw dust and coffee waste. Increased growth of mycelim and yield of sporophore was obsewed by adding tannin up to 0.1% as substrate.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.171-178
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• 1991

The two-stage enzyme reactor, packed with cyclodextrin glucanotransferase (CGTase) immobilized on Amberite IRA 900, coupled with ultrafiltration membrane was investigated for continuous production of cyclodextrin (CD). 5% (w/v) of soluble starch was partially cyclized, in the 0.1 l first-stage immobilized enzyme reactor, up to CD conversion yield of 10% (w/w) at retention time of 0.56hr and 1.5 units of immobilized CGTase/1g of carrier. In the second stage main immobilized enzyme reactor capacity of 1.5 l, the maximum CD conversion yield of 39% (w/v) was achieved at retention time of 2.8hr and 0.47 unit of CGTase/1 g of carrier. Unreacted residual dextrin was fractionated with ultrafiltration membrane, and then, recycled into the second-stage main bioreactor to increase the CD conversion yield. The most suitable membrane size and the volume concentration ratio (concentrate: filterate) for recycling of unreacted residual dextrin were found to be 5K dalton and 4:6, respectively. CD conversion yield was increased about 3~4% upon co-immobilization of pulluanase along with CGTase. Spent Amberite IRA 900 can be reutilized consecutively more than 3 times for immobilization of CGTase after regeneration.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.930-937
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• 2005

The Plackett-Burman design and the response surface method (RSM) with a central composite design (CCD) were employed to develop a culture medium for ansamitocin P-3 production using Actinosynnema pretiosum ATCC 31565. Among the 11 nutrients tested using the Plackett-Burman design, two carbon sources, sucrose and dextrin, and two nitrogen sources, polypeptone and yeast extract, were selected. Optimization of the concentrations of the selected nutrients was then performed using RSM with CCD. After two rounds of RSM, the optimum concentrations ($\%w/v$) of sucrose, dextrin, polypeptone, and yeast extract were identified as 4.5, 4.5, 0.16, and 0.89, respectively. The maximum ansamitocin P-3 titer was 45.2 mg/l with the optimized medium, which was about 6 times higher than that (7.315 mg/l) obtained with an $R_{2}YE$ medium before optimization.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.109-114
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• 1997

The Oomycete Saprolegnia ferax produces an extracellular $\beta$-amylase, Maximum enzyme yield was attained after 7 days of growth in YNB starch medium (pH 6.5) at 25$\circ$C. The amylase was pu- rified 24-fold by ultrafitration, HPLC DEAE column and HPLC gel filtration. The purfied enzyme was a monomeric glycoprotein with a molecular weight of about 44,000 dalton. The pH and temperature optima were 6.5 and 50$\circ$C, respectively. The enzyme was fairly stable up to 50$\circ$C and at acidic pH region (pH 4.0-7.0). The apparent Km and Vmax values of the enzyme against soluble starch were 0.77 mg/ml and 2,174 $\mu$moles/mg protein, respectively. Amino acid analysis indicated that the enzyme was enriched in alanine, glycine, leucine and acidic amino acid. Starch hydrolysis with the enzyme released maltose but not glucose, whereas maltotriose, Schardinger dextrin ($\alpha$-cyclodextrin) and pullulan were not hydrolysed by the enzyme. The enzyme was inhibited by Schardinger dextrin, p-chloromercuribenzoate(PCMB), CU$^{2+}$' and Hg$^{2+}$. Inhibition of the enzyme by PCMB could be reversed by the addition of cysteine and mercaptoethanol.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.309-313
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• 1997

Bench scale Sikhyes were produced from rice and glutinous rice and limit dextrins in rice Sikhye and glutinous rice Sikhye were purified by ethanol precipitation and Biogel P-2 gel chromatography and FPLC on Superose 12 column and analyzed. The purified limit dextrin in rice Sikhye and glutinous rice Sikhye showed bot signal of $\alpha$-1,4- and $\alpha$-1,6-glucosidic linkage with its estimation ratio of 4.5:1 and 5.9:1, respectively, by 1H-NMR analysis. Limit dextrins were hydrolyzed by pullulanase. The enzyme hydrolysis products contained maltose, maltotriose, maltotetraose, maltopentaose and matohexaose. These results suggest that limit dextrins were composed of these maltoolgosaccharide series with $\alpha$-1,6-glucosidic bond.

• Korean journal of applied entomology
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• v.11 no.1
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• pp.5-9
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• 1972

The experiment was conducted to investigate the physiological characteristics on 16 Isolates of bacterial wilt pathogen, pseudomonas solanacearum E.F. Smith, those obtained from infected stems of tomatoes, hot-Peppers and eggplants. PSA and Sucrose medium favoured by the most of the isolates, and various degree of gelatin liquefaction occurred by each of nine isolates those alble to liquefy gelatin among 16 isolates tested. The most of the isolates except one, did not reduce methylen blue. All isolates did not utilize lactose, saccharose, and starch, although all isolates utilize the galactose. The utilization of dextrin, esculin, glucose, mannitol, raffinose and salicin was depended on each isolate.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.183-188
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• 1992

A soil bacterium which produces raw starch-digesting $\beta$-amylase in culture medium, has been screened from soils. One strain, isolated and identified as Bacillus polymyxa No. 26, was selected as a $\beta$-amylase producing bacterium. Morphological and biological characteristics of the strain were found to be similar to those of a strain belonging to B. polymyxa. The electron microscopic observations of the bacterial vegetative cells and sporulated cells were extensively done to know the corelation between the enzyme synthesis and sporulation. When the bacterium was cultured on the appropriate media (3% dextrin, 0.3% beef extract, 0.5% polypeptone, 1% yeast extract and 0.3% NaCl at pH 7.0 for 4 days) raw starch-digestible $\beta$-amylase was produced extracellularly. This strain produced 130 units of $\beta$-amylase per ml in a culture medium containing 3% dextrin at $30^\circ{C}$. This value is compared to those of other $\beta$-amylase-producing strains. The optimum pH and temperature for crude enzymes were pH 6.5 to 7.0 and $50^\circ{C}$, respectively. The enzymes were stable between pH 5.5 and 9.0 for 30 min at $45^\circ{C}$.

• The Korean Journal of Food And Nutrition
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• v.11 no.2
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• pp.143-149
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• 1998

Sugars in Korean beer(3 brands) and Japanese beer(21 brands) were studied by HPLC and TLC. Total sugar of beer were estimated to 1.71∼3.93%(average 3.15%). Ethanol 4.5% class beers were estimated to 3.24% for Korean brands and 2.5% for Japanese brands. Ethanol 5% and 5.5% class beer were estimated to contain 3.2% for Japanese brands, respectively. Maltooligosaccharide series from glucose to maltodecaose were detected in the test of TLC and HPLC. No fermentable maltooligosaccarides and limit dextrin were estimated to 2.32%. But sugars in Korean Sikhye, rice drink saccharifide by malt, were not detected maltooligosaccharide series form maltotetraose to maltoheptaose.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1338-1346
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• 2006

Ansamitocin P-3 is a potent antitumor agent produced by A. pretiosum. A deletion mutant of A. pretiosum was constructed by deleting the asm2 gene, a putative transcriptional repressor. The deletion mutant showed a 9-fold enhanced ansamitocin P-3 productivity. The response surface method with central composite design was employed to further optimize the culture medium composition for ansamitocin P-3 production by the deletion mutant. The concentrations of four medium ingredients, dextrin, maltose, cotton seed flour, and yeast extract, which have been reported as major components for ansamitocin production, were optimized through a series of flask culture experiments. The optimum concentrations of the selected factors were found to be dextrin 6.0%; maltose 3.0%; cotton seed flour 0.53%; and yeast extract 0.45%. The maximum titer of ansamitocin P-3 was 78.3 mg/l with the optimized composition, about 15-folds higher than the unoptimized titer of 5.0 mg/l obtained with YMG medium.

• Microbiology and Biotechnology Letters
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• v.5 no.1
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• pp.5-12
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• 1977

As a basic study for the application of the spore-tearing lactic acid bacteria to foods, the effects of the sporulating conditions on the growth and sporogenesis were studied were observed. The results obtained are as follow. 1. All carbohydrates added to sporulation media except dextrin decreased the sporulation rate and the thermal resistance of spores. Dextrin stimulated the growth, however, there in no effect on the thermal resistance. 2. As nitrogen source, the protein hydrolysates such as peptone, casamino acid were effective to obtain were spores of the increased thermal resistance. 3. Ca$\^$＋＋/, Mn$\^$＋＋/ of the metal ions added to casamino acid containing medium validly increased the total growth, sporulation rate and thermal resistance. Its optimum concentration was 40 ppm each. 4. Biotin of vitamines had an effect on the total growth, sporulation and thermal resistance of spores. Its optimum concentration was 30${\gamma}$/ml. 5. The resistant spores required the adequate maturation period, more than 36 hours, sufficient aeration. and optimum temperature, 37∼45$^{\circ}C$.