• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.46-52
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• 2002

As a functional additive for intestinal microflora, panose ($6^2-{\alpha}$-D-glucopyranosylmaltose) was synthesized during kimchi fermentation using the glucose transferring reaction of glucansucrase from Leuconostoc mesenteroides. For the glucose transferring reaction, sucrose and maltose were added ($2\%$ each, w/v) to dongchimi-kimchi as the glucosyl donor and acceptor molecule, respectively. After five days of incubation at $10^{\circ}C$, referring to the initial phase for the production of lactic acid in kimchi, over $60\%$ (w/v) of the total sugars were converted into panose and other branched oligosaccharides. Thereafter, the kimchi was stored at $4^{\circ}C$ and the amount of panose remained at a constant level for three weeks, thereby indicating the stability of panose to microbial degradation during the period of kimchi consumption. The use of maltose as the acceptor molecule in the kimchi also facilitated a lower viscosity in the kimchi-juice by preventing the synthesis of a dextran-like polymer which caused an unfavorable taste. Accordingly, the application of this new method of simultaneous biocatalytic synthesis of oligosaccharides during lactate fermentation should facilitate the extensive development of new function-added lactate foods.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.325-330
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• 1991

In order to develop yeast strains which can effectively produce ethanol from cellulosic hydrolyzates, protoplast fusion between Candida sp. KM-09-135 and Saccharomyces cweoisiue SM-07 was carried out and obtained the excellent fusant KMS-23. Fusant KMS-23 showed the optimal growth temperature and ethanol productivity at $37^{\circ}C$, and assimilated xylose, cellobiose, maltose and raffinose as fermentative sugars. Cell size of the fusant was about 1.2 times greater than that of KM-09-135 and 1.5 times SM-07. DNA content of fusant was 1.3 times higher than that of SM-07 and similar with KM-09-135. Fusant KMS-23 produced 2.57% (v/v) ethanol from saccharified wheat bran containing 6.44% (w/v) of reducing sugar, which was 1.3 times higher than parent strains under the same conditions.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.185-192
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• 2009

Chungkookjang fermenting Bacillus subtilis 028-1 strain suppressed the growth of Staphylococcus sp. LS2, Saccharomyces cerevisiae, and Candida albicans. B. subtilis 028-1 strain produced antibiotic effectively in the medium of 2% soybean meal and 1% maltose as a disaccharide, when the shaking was continued 15~18 h and the pH of culture medium was maintained under 6.5. The antibiotic activity was optimized when the initial pH of the culture medium of test strain was adjusted with weak alkali, was remained after 20 min of boiling and for more than 1 month in room temperature, and was weakened slowly by the digestion of chymotrypsin and papain. The molecular weight of the antibiotic was identified between 500 and 1,000 dalton by dialysis, and antibiotic substance was considered as not surfactin but a member of iturin family because of the absence of fibrinolytic activity.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.189-196
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• 1992

A $\alpha$-l, 4-D-glucan maltohydrolase $(\beta$-amylase), secreted by the mesophilic aerobic bacterium Bacillus polymyxa No.26, was purified and characterized. The enzyme production was increased after a logarithmic phase of bacterial growth and paralleled with the onset of bacterial sporulation. By applying anion exchange chromatography and gel filtration the enzyme was purified 16.7-fold and had a specific activity of 285.7 units/mg. Two enzyme activities were eluted on a column of DEAE-Sephadex chromatography, and they were designated as E-I for a major enzyme peak and E-II for a minor peak. Of them, E-I enzyme peak was further purified by using gel chromatography. The molecular mass of this enzyme was determined to be 64, 000 daltons and consisted of a single subunit, showing an isoelectric point of 8.9. The enzyme was able to attack specifically the $\alpha$-l, 4-glycosidic linkages in soluble starch and caused its complete hydrolysis to maltose and $\beta$-limited dextrin. This amylolytic enzyme displayed a temperature optimum at $45^\circ{C}$ and a pH optimum at 7.0. The amino acid composition of the purified enzyme was quite similar to the other bacterial $\beta$-amylases reported. Surprisingly, the purified enzyme from this aerobe only exhibited hydrolytic activity on soluble starch, not on starch granules. The degradation of from starch by $\beta$-amylase was greatly stimulated by pullulanase addition. These results differentiated from other $\beta$-amylases reported. Based on a previous result that showed the enzyme system involves in effective degradation of raw starch granules, this result strongly suggested that the purified enzyme (E-I) can be a synergistic part of starch granule-digestion and E-II plays a crucial role in digestion of starch granules.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.246-250
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• 2001

In order to produce alkaline protease, psychrotrophic Bacterium which have high enzyme activity, was isolated by using enrichment culture from soil samples and identified as genus Bacillus sp. The optimal pH and temperature for the enzyme activity were pH 6 and $40^{\circ}C$. The temperature range of high enzyme activity was $20{\sim}40^{\circ}C$. The optimal initial pH of culture condition for enzyme was pH 6. The most favorable carbon and nitrogen sources for the production of protease by Bacillus sp. WRD-2 were 3% maltose and 4% yeast extract, respectively.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.178-183
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• 2005

A strain WL-2 was isolated from soil as a producer of the extracellular xylanase, which catalyzes the hydrolysis of oat spelt xylan. The strain WL-2 was identified as Streptomyces sp. on the basis of its 16S rRNA sequence, morphology, cultural and physiological properties. The xylanase of culture filtrate was the most active at $60^{\circ}C$ and pH 6.0, and retained $90{\%}$ of its maximum activity at range of pH $4.5{\~}6.5$. In order to optimize the culture medium for xylanase production, ingredients of G.S.S medium were replaced by several carbohydrates. The carbohydrates such as ${\alpha}-cellulose$, oat spelt xylan and maltose increased dramatically the xylanase productivity of Streptomyces sp. WL-2. The maximum xylanase productivity was reached to 120 U/ml in the modified medium containing $1{\%}\;\alpha-cellulose$ and $1\%}$ maltose.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.22-29
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• 1975

Conditions for submerged culture of Agaricus campestris var. bisporus and the chemical composition of its mycelium were investigated. In shaking culture with TGY basal medium at $27{\sim}30^{\circ}C$, pH tended to increase upon culture period, mycelial growth was the highest on 12th day, with relatively high nitrogen content of 7% and sugar in the medium disappeared almost at the end of culture period. As a nitrogen source, ammonium phosphate (dibasic) gave relatively high mycelial yield and the addition of yeast extract gave rise to better results. As a carbon source, glucose was the best, fructose, maltose, lactose and sucrose gave the same results, and soluble starch was utilized slightly. Mushroom mycelium contained 48% of protein, 8 free amino acids including arginine, histidine, lysine, isoleucine, leucine, phenylalanine, proline, tyrosine and its protein consisted of most essential amino acids, with relatively high contents of lysine and threonine. Therefore, mushroom mycelium deserves to be a high quality protein food.

• KSBB Journal
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• v.15 no.1
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• pp.27-34
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• 2000

A marine bacterium having a high oil-degrading activity was isolated form the oil-polluted southern sea of Korea, and was identified as Pseudomonas aeruginosa and was named Pseudomonas aeruginosa BYK-2. The optimal tmeperatur, culture time, pH and NaCl concentration for biosurfactant production and cell growth showed $25^{\circ}C$, 48h, 7.0 and 0%(w/v), respectively. After cultivation at $25^{\circ}C$, 180 rpm in 250 mL erlenmeyer flask for 7days, 1%(w/v) arabian light crude oil and bunker C oil which are considered to be hardly degradable compounds were degraded 92.1%(w/w) and 76%(w/w) respectively. And then, cell adherence was measured on various carbon sources. The cell adherence indicated over 80% on hydrocarbons(arabian light crude oil, kuwait curde oil, bunker C oil, n-paraffine, n-hexadecane, n-tetradecane) as carbon sources. Lecithin among fatty acids(oleic acid, olive oil, lecithin) showed highest cell adherence of 91.5%. The cell adherence of sugars(arabinose, trehalose, dextrose, galactose, lactose, fructose, maltose, sorbitol, sucrose) observed to be less than 70% except for arabinose, galactose, sorbitol and sucrose.

• 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.

• Molecules and Cells
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• v.25 no.3
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• pp.446-451
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• 2008

We assessed heterologous protein expression in 64 strains obtained from the Escherichia coli Reference (ECOR) collection, a collection representing diverse natural E. coli populations. A plasmid generating a glutathione S-transferase and plant carbonic anhydrase fusion protein (GST-CA) under the control of the tac promoter was introduced into the ECOR strains, and the quantity of the fusion protein was determined by SDS-PAGE. The foreign protein was generated at various levels, from very high (40 strains, high producers) to very low (six strains, low producers). Immunoblotting showed that the high producers expressed approximately 250-500 times more GST-CA protein than the low producers. The results of semi-quantitative RT-PCR showed that the low producers generated mRNA levels comparable to those of the high producers, thereby suggesting that, at least in this case, inefficient translation is a major cause of the low production. We introduced a different plasmid, which expressed a maltose binding protein and plant guanylate kinase fusion protein (MBP-GK) into the six low producers. Interestingly, five of these expressed MBP-GK at very high levels. Thus, we conclude that the production of a particular protein from an expression vector can vary considerably, depending on the host strain. Strains in the ECOR collection could function as useful alternative hosts when a desired level of protein expression is not obtained from commonly used strains, such as E. coli K12 or B derivatives.