• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.199-202
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• 2000

Optimization of submerged culture conditions for the production of exo-biopolymer from Paecilomyces japonica was studied. Maltose, yeast extract and potassium phosphate were the most suitable sources of carbon, nitrogen, and inorganic salt, respectively, for both production of the exo-biopolymer and mycelial growth. The optimal culture conditions in flask culture were pH 5.0, $25^{\circ}C$ and 150 rpm in a meidum containing of 30 g maltose, 6 g yeast extract, 2 g polypeptone, 0.5 g $K_2HPO_4$, 0.2 g $KH_2PO_4$, 0.2 g $MnSo_4\;{\cdot}\;5H_2O$, 0.2 g $MgSO_4\;{\cdot}\;7H_2O$ in 1-L distilled water. Exo-biopolymer production and mycelial growth in the suggested medium were significantly increased in a 2.5-L jar fermentor, where the maximum biopolymer concentration was 8 g/1.

• KSBB Journal
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• v.9 no.2
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• pp.133-139
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• 1994

Oligosaccharide formation and the production of transfructosylase and transglucosylase by Aureobasidium pullulans were studied in sucrose or maltose media, respectively. The initial uptake rates of substrate in sucrose-rich media were faster than that in maltose-rich media, also most parts of oligosaccharides formed and other monosaccharides released were utilized progressively as substrate during the cultivation periods. However, when the initial amount of sucrose was raised to $100g/\ell$, high concentration of monosaccharides were liberated, consequently high-level fructose was accumulated unused during fermentation. The biggest molecule of oligosaccharide synthesized was hexasaccharide in all cultivation media examined, of which the organism could not utilize isomalto-oligosaccharide of DP6 synthesized in a maltose-rich medium. The maximum amount of oligosaccharides produced was $58g/\ell$ when $100g/\ell$ of sucrose and $5g/\ell$ of maltose were used as initial substrate. From the early stage of growth both fructooligosaccharides and isomalto-oligosaccharides were synthesized and progressively utilized as substrates during the fermentation. Based on the experimental results, it was suggested that maltose could induce both transfructosylase and transg1ucosylase, whereas sucrose was unable to slimulate transglucosylase formation.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.34-39
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• 2016

Wild-type yeast strains were isolated from nuruk, a type of microbial starter culture used for fermenting grains to produce alcoholic products, that was collected from different areas in Korea. Strains were identified based on the analysis of 18S rRNA sequences. Fifty strains shared the highest sequence similarity with Saccharomyces cerevisiae and were designated MBYK1-MBYK50. Among these S. cerevisiae isolates, MBYK45 produced $44.0{\pm}0.3g$ of ethanol from 200 g maltose after incubation at $30^{\circ}C$ for 48 h. Maximum ethanol production of $110.80{\pm}0.81g/l$ with productivity of $3.79{\pm}0.14g^{-1}l^{-1}h^{-1}$ was obtained at optimum culture conditions of pH (6.0), maltose (200 g/l), and temperature ($35^{\circ}C$). This study indicates that the MBYK45 strain of S. cerevisiae, isolated from nuruk, might be suitable for traditional liquor production from malts.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.293-298
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• 1986

Sisomicin, which is one of aminoglycoside antibiotics, was produced by Micromonospora inyoensis. The effects of carbon sources on sisomicin production were studied in batch cultures. Starch, dextrin and maltose were good carbon sources for the production of sisomicin. However, when glucose was used, the antibiotic productivity decreased significantly due to a carbon catabolite regulation. The carbon catabolite regulation depends mostly on carbon catabolite repression, but not on carbon catabolite inhibition. On the other hand, the growth-production curves of batch cultures show that sisomicin is produced most actively during the idiophase.

• Journal of Microbiology and Biotechnology
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• v.20 no.5
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• pp.950-957
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• 2010

Serratiopeptidase (SRP), a 50 kDa metalloprotease produced from Serratia marcescens species, is a drug with potent anti-inflammatory property. In this study, a powerful statistical design, evolutionary operation (EVOP), was applied to optimize the media composition for SRP production in shake-flask culture of Serratia marcescens NRRL B-23112. Initially, factors such as inoculum size, initial pH, carbon source, and organic nitrogen source were optimized using one factor at a time. The most significant medium components affecting the production of SRP were identified as maltose, soybean meal, and $K_2HPO_4$. The SRP so produced was not found to be dependent on whey protein, but rather was notably induced by most of the organic nitrogen sources used in the study and free from other concomitant protease contaminant, as revealed by protease inhibition study. In addition, experiments were performed using different sets of EVOP design with each factor varied at three levels. The experimental data were analyzed with a standard set of statistical formula. The EVOP-optimized medium, with maltose 4.5%, soybean meal 6.5%, $K_2HPO_4$ 0.8%, and NaCl 0.5% (w/v), gave a SRP production of 7,333 EU/ml, which was 17-fold higher than the unoptimized media. The application of EVOP resulted in significant enhancement of SRP production.

• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1455-1464
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• 2021

Trehalose is a non-reducing disaccharide in increasing demand for applications in food, nutraceutical, and pharmaceutical industries. Single-step trehalose production by trehalose synthase (TreS) using maltose as a starting material is a promising alternative process for industrial application due to its simplicity and cost advantage. Pseudomonas monteilii TBRC 1196 was identified using the developed screening method as a potent strain for TreS production. The TreS gene from P. monteilii TBRC 1196 was first cloned and expressed in Escherichia coli. Purified recombinant trehalose synthase (PmTreS) had a molecular weight of 76 kDa and showed optimal pH and temperature at 9.0 and 40℃, respectively. The enzyme exhibited >90% residual activity under mesophilic condition under a broad pH range of 7-10 for 6 h. Maximum trehalose yield by PmTreS was 68.1% with low yield of glucose (4%) as a byproduct under optimal conditions, equivalent to productivity of 4.5 g/l/h using enzyme loading of 2 mg/g substrate and high concentration maltose solution (100 g/l) in a lab-scale bioreactor. The enzyme represents a potent biocatalyst for energy-saving trehalose production with potential for inhibiting microbial contamination by alkaline condition.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.59-63
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• 2008

Rapid production of therapeutic proteins such as angiostatin and endostatin angiogenic inhibititors has been highly demanded for cancer treatment. In this regard, recombinant human angiostatin and endostatin were successfully expressed as soluble forms by maltose binding protein (MBP)-mediated fusion expression in Escherichia coli. PCR amplified, angiostatin and endostatin genes from human placenta cDNA library were inserted into an expression vector pMAL-c2e to construct prokaryotic expression vectors, pMAL-c2e/AS and pMAL-c2e/ES, respectively. Recombinant angiostatin and endostatin were efficiently expressed in E. coli origami (DE3) after IPTG induction and protein expression were confirmed by SDS-PAGE analyses. The expressed recombinant proteins were purified near homogenity using an amylose affinty column chromatography. In contrast that previous E. coli expressions were all insoluble, our results first time demonstrated that MBP fused human angiostatin and endostatin were soluble in E. coli.

• The Korean Journal of Food And Nutrition
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• v.8 no.3
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• pp.165-171
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• 1995

Sikhye is a traditional sweet rice drink in Korea by $\beta$-amylase's saccharifing action. Sikhye has great potentiality for commercial beverage because of It's characteristic taste and flavors. But, the chemical compositions and production methods of Sikhye are little known. The total amount of carbohydrate of sixteen Sikhye selected in Korean market was 11~15%. The reducing sugar by the Somogyi-Nelson's method was measured 0.4~2% as maltose, which has little influence on the sweetness of Sikhye. While sucrose content was about 10% by the TLC and Seliwanoff analysis. It means that carbohydrate in Sikhye was almost sucrose. Furthermore the most of Sikhye has brown color and turbidity. To improve the quality of Korean Sikhye, it is necessary to increase the production of maltose and to reduce brown color and turbidity, without adding sucrose.

• The Korean Journal of Food And Nutrition
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• v.9 no.1
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• pp.45-51
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• 1996

Korean traditional Sikhye is made from rice and malt, and It's main product Is maltose. However commercial Sikhye differs from traditional Sikhye because it's main component is sucrose. Sikhye industry faces many problems such as contamination of malt with microorganisms, low amylase activity of malt and technical difficulties. There is no commercial Sikhye which is only using rice and malt by these reasons. To produce the traditional Sikhye free from these problems, it is necessary to restrict the microorganisms of malt and to standardize the amylase activity of malt. In addition, the Introduction of effective control and sanitaric process is required. In Sikhye production. if $\beta$-amylase and isoamylase or pullulanase were added, starch could be saccharified 100% as maltose. Accordingly, this method brings us the low cost of Sikhye.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.482-487
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• 2000

Optimization of submerged culture conditions for the production of exo-biopolymer from Paecilomyces japonica ws studied. Maltose, yeast extract, and potassium phosphate were the most suitable sources of carbon, nitrogen, and inorganic salt, respectively, for both production of the exo-biopolymer and mycelial growth. The optimal culture conditions in a flask culture were pH 5.0, $25^{\circ}C$, and 150 rpm in a medium containing (as in g/l) 30 maltose, 6 yeast extruct, 2 polypeptone, $0.5{\;}K_3HPO_4,{\;}0.2{\;}KH_2PO_4,{\;}0.2{\;}MnSO_4{\cdot}5H_2O,{\;}0.2{\;}MgSO_4{\cdot}7H_2O$. Exo-biopolymer production and mycelial growth in the above suggested medium were significantly increased in a 2.5-1 jar fermentor, where the maximum biopolymer concentration was 8 g/l. The morphological changes of the mycelium in the submerged culture were observed within pH ranges from 4.0 to 9.0; i.e., growth of the filamentous form was optimal at culture pHs of 5.0 and 6.0, whereas pellet was formed at other pHs.