• Journal of the Korean Chemical Society
• /
• v.48 no.6
• /
• pp.616-622
• /
• 2004

Liposome powders were prepared by a freeze-drying method for the application to the field of drug carrier. The effect of maltose as a liposome stabilizer was studied on the stability and the drug-loading efficiency of the freeze-dried liposome powders. The particle size of liposomes before and after freeze-drying was determined to evaluate the liposome stability. The drug-loading efficiency was measured by Fluorescence spectrophotometer using calcein as a model drug. When maltose was added after the preparation of the liposomes, the liposomes was stable, compared to the case of maltose addition at the hydration procedure. By the addition of maltose, the liposome was stable for 30 days at $4{\sim}37^{\circ}C$, while the particle size of the liposome without maltose increased with time. The liposome showed relatively high stability when the maltose/lipids molar ratio was 3 and 6.

• Journal of Microbiology and Biotechnology
• /
• v.7 no.3
• /
• pp.204-208
• /
• 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
• /
• v.24 no.4
• /
• pp.404-407
• /
• 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.

• Journal of Sericultural and Entomological Science
• /
• v.41 no.1
• /
• pp.9-13
• /
• 1999

The experiment was carried out to investigate the absorption profile of blood glucose in mice administered to silkworm powder MeOH extract. The mice was injected to oral load of maltose, sucrose and lactose(2 g/kg) and silkworm powder MeOH extract at the same time. After injecting the sample, blood glucose concentration was measured at 0, 30, 60, 120, 180 and 240 minutes. Blood glucose lowering effect of silkworm powder for loading maltose was 69% in postprandial 30 minutes. After the postprandial 60 minutes, the glucose was absorbed slowly. Total amount of blood glucose absorption in mice administered to maltose were 560.7 mg/dl during 240 minutes. That of silkworm powder MeOH extract marked 534.7 mg/dl. Total amount of blood glucose from oral loading sucrose reached to 508.9 mg/dl. That of loading silkworm powder MeOH extract were 468.8. But, silkworm powder was not inhibited lactose absorption. As a above results, silkworm powder inhibits the transient rising of blood glucose after postprandial 30 minuts through inhibition of ${\alpha}$-glucosidases. In case of starvation silkworm powder don't promote the hypoglycemia. In addition, silkworm powder induces the delay absorption of glucose without loss of it.

• BMB Reports
• /
• v.35 no.6
• /
• pp.568-575
• /
• 2002

An $\alpha$-amylase (EC 3.2.1.1) was purified that catalyses the production of a high level of maltose from starch without the attendant production of glucose. The enzyme was produced extracellularly by thermophilic Streptomyces sp. that was isolated from Thailand's soil. Purification was achieved by alcohol precipiation, DEAE-Cellulose, and Gel filtration chromatographies. The purified enzyme exhibited maximum activity at pH 6-7 and $60^{\circ}C$. It had a relative molecular mass of 45 kDa, as determined by SDS-PAGE. The hydrolysis products from starch had $\alpha$-anomeric forms, as determined by $^1H$-NMR. This maltose-forming $\alpha$-amylase completely hydrolyzed the soluble starch to produce a high level of maltose, representing up to 90%. It hydrolyzed maltotetrose and maltotriose to primarily produce maltose (82% and 62%, repectively) without the attendant production of glucose. The high maltose level as a final end-product from starch and maltooligosaccharides, and the unique action pattern of this enzyme, indicate an unusual maltose-forming system. After the addition of the enzyme in the bread-baking process, the bread's volume increased and kept its softness longer than when the bread had no enzyme.

• Korean journal of food and cookery science
• /
• v.31 no.5
• /
• pp.574-580
• /
• 2015

This study investigated the proximate composition, sweetness, color, texture, and sensory properties of baked Gangjung prepared using different coating syrups (maltose syrup, oligosaccharide, rice syrup, and maltitol syrup). The crude protein content was 3.22~3.28% in baked Gangjung prepared with maltose syrup, oligosaccharide, or rice syrup, while that prepared using maltitol syrup had 2.61%. Crude ash was the highest when rice syrup was used (1.08%), and the lowest when maltose syrup or oligosaccharide was used (0.64% and 0.68%, respectively). The sweetness of the baked Gangjung was the highest in the rice syrup group, at $70.07^{\circ}Brix$, and lowest in the maltose syrup group, at $33.5^{\circ}Brix$ (p<0.05). The hardness of the Gangjung prepared with the different coating syrups was the highest for the grain syrup (1.42), followed by the oligosaccharide group at 0.96, maltose syrup (0.40), and maltitol syrup (0.35) (p<0.05). The number of peaks and the indirect measure of crispness also showed the highest values for the rice syrup group (p<0.05), but there was no significant difference among the values in the other groups. Lightness was in the range of 63.26~73.04 depending on the coating syrup, decreasing from the oligosaccharide to the maltitol, rice syrup, and then to the maltose syrup group (p<0.05). The a-value was the highest for the maltose and rice syrup groups at 10.69 and 10.38, respectively (p<0.05), and the b-value showed the same trend. Baked Gangjung showed the highest scores for color, flavor, and overall preference when prepared using maltitol syrup.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.3 no.2
• /
• pp.82-86
• /
• 1998

The maltose binding protein (MBP) fusion protein system is a versatile tool to express and isolate recombinant proteins in E. coli. In this system, MBP fusion proteins are efficiently isolated from whole cell lysate using amylose conjugated agarose beads and then eluted by competition with free maltose. Since MBP is a rather large molecule (∼42 kDa), for further experiments, the MBP part is usually proteolytically cleaved from the fusion protein and subsequently removed by ion-exchange chromatography or rebinding to amylose columns after washing out excess and MBP-bound maltose. In the present study, we have developed an improved method for the removal of cleaved MBP, which is advantageous over conventional methods. In this method, factor Xa cleaved MBP fusion proteins were incubated with Sepharose beads conjugated with MBP specific monoclonal antibodies and then precipitated buy centrifugation, resulting in highly purified proteins in the supernatant.

• Preventive Nutrition and Food Science
• /
• v.20 no.2
• /
• pp.102-109
• /
• 2015

In order to investigate the thermal degradation of glucose and maltose solutions after high temperature and high pressure (HTHP) treatment, the samples were treated at temperatures of 110, 120, 130, 140, and $150^{\circ}C$ for 1, 2, 3, 4, and 5 h in an apparatus for HTHP treatment. Glucose and maltose solutions (20% w/w) were prepared by weighing glucose and maltose and adding distilled water in the desired proportion. Chromaticity, pH, organic acids, 5-hydroxymethylfurfural (HMF), free sugar contents, electron donating ability (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) were evaluated. With increasing heating temperatures and times, the L-, a-, and b-values decreased. The pH and free sugar contents decreased, and organic acids and HMF contents increased with greater temperatures and times. EDA (%) and the AEAC of the heating sugars increased with the increases in temperatures and times.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.235-238
• /
• 2002

Leuconostoc mesenteroides B-512FMCM, 742CB3, 1299C의 dextransucrase들의 glycosyl기 전이 특성을 수용체 반응과 transglycosylation반응을 통해 확인하였다. 수용체 반응의 경우 10% sucrose에 수용체로 4% maltose를 첨가하여 반응시켰고 transglycosylation반응은 다른 크기, 다른 농도 그리고 다른 종류의 가지 결합의 dextran 을 합성하는 효소들을 이용하여 수행하였다. 각각의 효소들은 maltose를 이용한 수용체 반응에서 유사한 종류의 수용체 산물들을 합성한 것에 비해 세 dextransucrase들 (512FMCM, 742CB3, 1299C) 을 일정 비율로 혼합하여 maltose를 이용한 수용체 반응 결과 512FMCM 효소의 활성 비율을 줄이고 742CB3, 1299C 효소의 활성 비율을 증가시켰을 경우에는 ${\alpha}-1{\rightarrow}$3 의 가지결합이 많은 dextran 을 합성하였다. 또한, 세 가지 다른 구조의 dextran(T40, 742CB, B1299)에 100mM maltose을 수용체로 첨가해 각각의 dextransucrase(512FMCM, 742CB3, 1299C)와 transgly cosylation을 수행한 결과 1299C 효소가 세 종류의 dextran(T40, 742CB, B1299) 에 모두 가지 결합이 많은 dextran을 합성함을 확인하였다. 또한 ${\alpha}-1{\rightarrow}$6 결합으로 주로 이루어진 2%, 5% dextran(T10, T40, T7O, T500, T2000)에 dextransucrase(512FMCM, 742CB3, 1299C)를 반응시켜 기존의 dextran 보다 가지 결합이 더 많이 형성된 transglycosylation 산물을 합성하였다. 이때 maltose를 첨가했을 경우 이 수용 체에 의해 많은 ${\alpha}-1{\rightarrow}$6 가지 결합의 dextran 을 합성함을 확인하였다.

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