• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.106-113
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• 1994

A novel method for production of concentrated purity maltose using swollen extruded corn starch was investigated. Degree of gelatinization of extruded starch suitable for maltose formation was found to be around 70%. The optimal amiunt of enzyme was 400 unit fungal $\alpha $-amylase per g of starch, and the reaction time was 12 hours. At extruded starch concentration of 300 g/l(w/v), maltose concentration and content were reached up to 220 g/l(w/v) and 77%(w/w), respectively. The maltose forming reaction was also successfully proceeded at high starch concentration of 700 g/l(w/v), however, the conversion yield and content were decreased. By the addition of extruded starch by fed-batch wise, the maltose concentration, purity, and conversion yield could be improved up to 465 g/l(w/v), 70%(w/w), and 0.63, respectively. The investigated maltose production process seems to have many potential advantages over the conventional process utilizing liquefied starch, and the feasibility for industrial application needs to be evaluated.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.13-16
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• 2001

Maltose and soluble starch were used as secondary sources of carbon for glucoamylase production by Aspergillus awamori in solid state fermentation. During batch cultivation, maltose above 2.5%(w/w) repressed glucoamylase production, but, by adding either 2.5% (w/w) maltose or 1.25% (w/w) soluble starch to fed-batch cultivations, glucoamylase activity was increased by 15% and 170% over standard medium, respectively. The data showed that maltose is a weak inducer of glucoamylase production in solid stat fermentation.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.404-407
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• 1996

The effects of carbon sources on vancomycin production were investigated using Nocardia orientalis CSVC 3300. Among carbon sources tested, glucose, maltose and fructose were effective for the production of vancomycin. Glucose was favored for growth, but decrease the production of vancomycin at the concentration above 7.5%. In comparison, maltose did not decrease the production of vancomycin up to the concentration of 20%. When the mixture of glucose and maltose was used in the ratio 1:3 to 1:4, the highest production of vancomycin was achieved. When glucose concentration was set at 3.0%, catabolite repression could not be observed up to total sugar concentration of 16.0%. Fermentation was carried out using commercial hydrolyzed starch composed of glucose, maltose, maltotriose and maltotetraose, The initial glucose concentration was set at 3.0% and subsequent oligosaccharide consumption was monitored by checking their supernatant with HPLC. During initial cultivation for 38 hour, glucose was the sole carbon source leading to rapid growth. After cell growth stopped, the maltose and glucose concentrations increased due to degradation of maltotriose and maltotetraose, but glucose level was maintained at around 3.0%. After 70 hour fermentation, maltose slowly converted to glucose, and vancomycin production continued during the period.

• KSBB Journal
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• v.9 no.4
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• pp.428-435
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• 1994

Cell growth and production of ${\alpha}$-amylase, acetic acid and lactic acid were investigated in Bacillus amyloliquefaciens(ATCC 23350) flask culture with various carbon sources. Maximum dry cell density increased with increase in initial maltose concentration. Maximum dry cell density was the highest(1.4g/$\ell$) at 10g/$\ell$ of initial glucose concentration. With 10g/$\ell$ of initial glucose concentration, maximum specific cell growth rate was obtained. Among the various carbon sources maximum ${\alpha}$-amylase production was obtained with 149 unit/ml at 20g/$\ell$ of initial maltose concentration. With 5g/$\ell$ of initial maltose concentration, maximum ${\alpha}$-amylase production rate was obtained. By increasing carbon source concentration, acetic acid formation decreased. Acetic acid formation was higher in glucose than in maltose. By increasing carbon source concentration, lactic acid formation increased. Lactic acid formation was higher in maltose than in glucose.

• Journal of Microbiology and Biotechnology
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• v.7 no.3
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• pp.204-208
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• 1997

Aureobasidium puliulans possesses the capacity for simultaneous formation of fructosyltransferase and glucosyltransferase in various sugar media including sucrose, maltose, glucose and fructose. Among them, sucrose (300 g/1) was the most suitable carbon source for fructosyltransferase production, while fructose (100 g/1) gave the maximal production of glucosyltransferase. There existed a critical concentration for the optimal formation of enzymes in sucrose, glucose and fructose media. By contrast, no effect of maltose concentrations up to 300 g/1 was observed. The specific activity of the glucosyltransferase on maltose medium was highest during the early period of fetmentation, after which a sharp decrease occurred, whereas fructosyltransferase activity on sucrose medium maintained a nearly constant rate for a given culture period. Concomitant production of fructosyltransferase and glucosyltransferase was investigated with different combinations of lower concentrations of sucrose and maltose. Maltose supplementation in sucrose media and sucrose addition to maltose media enhanced the activity ratios of fructosyltransferase to glucosyltransferase as compared to that of non-supplemented media. Several polymers and surfactants were added in an attempt to enhance enzyme production, and supplementation of polyoxyethylene-sorbitan monolaurate (Tween 20) promoted fructosyltransferase production by 20%.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.283-289
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• 1994

The production of maltose utilizing swollen extrusion starch seems to have many technical advantages, such as, high reaction rate and high yield, production of high purity concentrated maltose, and low energy consumption, over the conventional method utilizing liquefied starch. The characteristics of maltose formation in heterogeneous enzyme reaction system comtaining swollen extrusion starch was investigated using fungal $\alpha $-amylase. The influence of extrusion conditions on structure of extruded starch, such as, degree of gelatinization, water absorption index, and water solubility index was analyzed. The relationship between the structural features and maltose forming reaction was investigated, and the result was analyzed in terms of surface reaction of insoluble extruded swollen starch. The characteristics of maltose formation from swollen sxtrusion starch was compared using endo-type fungal $\alpha $-amylase and exo-type $\beta $anylase, and the structural trasformation of extruded starch was also observed to clarify the reaction mechanism.

• KSBB Journal
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• v.9 no.2
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• pp.122-126
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• 1994

A new method for the production of isomalto-oligosaccharides from maltose was investigated using intact cells of Aureobasidium pullulaans which had been known to produce fructo-oligosaccharides. The cells showed transglucosylation activity producing isomalto-oligosaccharides at high concentrations of maltose, while they showed a hydrolytic activity at low concentrations of substrate when cultivated at $25^{\circ}C$. The optimum reaction conditions for the isomalto-oligosaccharide production were as follows: substrate concentration, 500g/l maltose; pH, 4.5; temperature, $65^{\circ}C$; cell dosage, 10 unit per gram substrate. Under optimized conditions, the maximum yield of isomalto-oligosaccharides achieved was around 48% (w/w). At the early period of reaction, panose was selectively produced from maltose, and thereafter isomaltotriose was synthesized by utilizing panose as a substrate when maltose consumption was discontinued.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.273-278
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• 1996

The research was undertaken to characterize the reaction mode of transglucosidase (TG) from Aspergillus niger for the production of isomaltooligosaccharides such as isomaltose, panose and isomaltotriose. TG hydrolyzed maltose to glucose units and produced panose and glucose by transglucosylation. TG hydrolyzed panose to maltose and glucose when panose was used as an initial substrate. The reaction patterns of products when isomaltose, isomaltotriose or isomaltotetraose were used as substrates were different from the case when maltose was used as a substrate. Maltotriose and maltose showed the same formation pattern of products. TG also produced isomaltooligosaccharides from maltooligosaccharides. The production of panote by TG from maltose was mathematically described by Michaelis-Menten kinetics. The kinetic constants, $V_{max}$ (the maximum velocity) and $K_m$ (Michaelis constant), were estimated by Lineweaver-Burk plot to be 400 M/min and 21.4 mM, respectively.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1054-1063
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• 2022

Trehalose is a non-conventional sugar with potent applications in the food, healthcare and biopharma industries. In this study, trehalose was synthesized from maltose using whole-cell Pseudomonas monteilii TBRC 1196 producing trehalose synthase (TreS) as the biocatalyst. The reaction condition was optimized using 1% Triton X-100 permeabilized cells. According to our central composite design (CCD) experiment, the optimal process was achieved at 35℃ and pH 8.0 for 24 h, resulting in the maximum trehalose yield of 51.60 g/g after 12 h using an initial cell loading of 94 g/l. Scale-up production in a lab-scale bioreactor led to the final trehalose concentration of 51.91 g/l with a yield of 51.60 g/g and productivity of 4.37 g/l/h together with 8.24 g/l glucose as a byproduct. A one-pot process integrating trehalose production and byproduct bioremoval showed 53.35% trehalose yield from 107.4 g/l after 15 h by permeabilized P. moteilii cells. The residual maltose and glucose were subsequently removed by Saccharomyces cerevisiae TBRC 12153, resulting in trehalose recovery of 99.23% with 24.85 g/l ethanol obtained as a co-product. The present work provides an integrated alternative process for trehalose production from maltose syrup in bio-industry.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.826-831
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• 2012

Acarbose, a pseudo-oligosaccharide, is widely used clinically in therapies for non-insulin-dependent diabetes. In the present study, S-adenosylmethionine (SAM) was added to selected media in order to investigate its effect on acarbose fermentation by Actinoplanes utahensis ZJB-08196. Acarbose titer was seen to increase markedly when concentrations of SAM were added over a period of time. The effects of glucose and maltose on the production of acarbose were investigated in both batch and fed-batch fermentation. Optimal acarbose production was observed at relatively low glucose levels and high maltose levels. Based on these results, a further fed-batch experiment was designed so as to enhance the production of acarbose. Fed-batch fermentation was carried out at an initial glucose level of 10 g/l and an initial maltose level of 60 g/l. Then, 12 h post inoculation, 100 ${\mu}mol/l$ SAM was added. In addition, 8 g/l of glucose was added every 24 h, and 20 g/l of maltose was added at 96 h. By way of this novel feeding strategy, the maximum titer of acarbose achieved was 6,113 mg/l at 192 h. To our knowledge, the production level of acarbose achieved in this study is the highest ever reported.