• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.316-317
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• 2011

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1639-1648
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• 2017

Curcumin is a natural polyphenolic compound, widely acclaimed for its antioxidant, anti-inflammatory, antibacterial, and anticancerous properties. However, its use has been limited due to its low-aqueous solubility and poor bioavailability, rapid clearance, and low cellular uptake. In order to assess the effect of glycosylation on the pharmacological properties of curcumin, one-pot multienzyme (OPME) chemoenzymatic glycosylation reactions with UDP-${\alpha}-{\text\tiny{D}}$-glucose or UDP-${\alpha}-{\text\tiny{D}}$-2-deoxyglucose as donor substrate were employed. The result indicated significant conversion of curcumin to its glycosylated derivatives: curcumin 4'-O-${\beta}$-glucoside, curcumin 4',4"-di-O-${\beta}$-glucoside, curcumin 4'-O-${\beta}$-2-deoxyglucoside, and curcumin 4',4"-di-O-${\beta}$-2-deoxyglucoside. The products were characterized by ultra-fast performance liquid chromatography, high-resolution quadruple-time-of-flight electrospray ionization-mass spectrometry, and NMR analyses. All the products showed improved water solubility and comparable antibacterial activities. Additionally, the curcumin 4'-O-${\beta}$-glucoside and curcumin 4'-O-${\beta}$-2-deoxyglucoside showed enhanced anticancer activities compared with the parent aglycone and diglycoside derivatives. This result indicates that glycosylation can be an effective approach for enhancing the pharmaceutical properties of different natural products, such as curcumin.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.1-12
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• 2002

Ecophysiologically diapause represents a syndrome of physiological and biochemical characteristics, all of which ensure survival during a long period of dormancy. Since, silkworm enters diapause as embryo at the early embryonic stage, the duration of egg life depends on the duration of embryonic diapause. The nature of diapause in silkworm, Bombyx mori, is primarily determined by genetic characters and endocrinologicnl mechanisms, mediated by environmental factors such as temperature and photoperiod. Hibernating potency value besides nucleic acid and carbohydrate metabolism, production and utilization of sorbitol are also equally responsible for induction, initiation, determination, maintenance and termination of diapause. Embryonic diapause in Bombyx moir, induced by active secretion of sub-oesophageal ganglion is attributed to hormonal system and metabolic adjustment, which serves to bring about a new physiological state. Metabolic conversion of trehalose to glycogen at induction, glycogen to sorbitol at initiation and sorbitol to glycogen at termination of diapause is correlated and in each metabolic shift a key enzyme becomes active in response to hormonal and environmental stimulation. An attempt has been made in this review article to discuss briefly the nature of embryonic diapause, influence of various factors on diapause nature, hormonal mechanism of diapause besides biochemical composition of egg, nucleic acid and carbohydrate metabolism, production and utilization of sorbitol in relation to induction, determination, maintenance, initiation and termination of diapause in the silkworm, Bombyx mori.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.501-506
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• 2019

New technology-driven biocatalysts are revolutionizing the biochemical industries. With maximum utilization of renewable feedstock, biocatalysts have been the basis for a major breakthrough. Lipases are the most widely established catalysts used for hydrolysis, esterification and transesterification reactions. In this research, a biochemical process that combines extraction of lipase enzyme from germinated wheat seeds and its application to valorize glycerol to acetins by esterification is presented. Acetins are among highly rated, value-added products derived from glycerol. The favorable conditions for the enzymatic conversion of glycerol were observed as glycerol to acetic acid molar ratio (1:5), reaction temperature ($40^{\circ}C$) and the amount of enzyme (20% v/v). 65.93% of glycerol conversion was achieved for duration of 15 h with the use of tert-butanol solvent. This method proposes to explore the viability of a biological route to convert glycerol derived from biodiesel industry to acetins with further streamlining.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.478-485
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• 2022

The certification performance issued through an external business is sold to companies subject to the emission trading system allocation, and the company subject to the allocation can secure the quota by converting the purchased external business certification performance into offset credits. In this methodology, when fossil fuels that used existing oil boilers (by oil type) were replaced with boilers using propane gas with a relatively low carbon content, the amount of carbon dioxide emission reduction by oil type was recognized. As an initial analysis to make up for the insufficient quota of large corporations, the amount of carbon reduction emissions and emission rights trading was calculated.

• Journal of Life Science
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• v.11 no.3
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• pp.230-234
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• 2001

The cyclodextrin glucanotransferase(CGTase) gene of Bacillus macerans was expressed in Saccharomyces cerevisiae and the recombinant CGTase was partially purified from the yeast culture supernatant. The optimal pH and temperature of the CGTase were found to be 6.0 and 5$0^{\circ}C$, respectively. The pH and temperature stabilities of the recombinant enzyme were significantly enhanced and the half life at 55$^{\circ}C$ was about 60 hr. When the recombinant CGTase was reacted with 5% soluble starch, the conversion yield of total cyclodextrin (CD) from starch was estimated to be 41% at 48 hr, whereas the wild type enzyme showed the yield of 12%. This improvement of conversion yield and thermal stability of CGTase may be useful for the development of low-cost CD production process.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.329-332
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• 2001

It has been known that, in enzymatic synthesis of cephalexin, the conversion yield was reduced by high loading of ampicillin acylase. In order to elucidate this phenomena, pH-controlled synthesis of cephalexin was examined using a purified Acetobacter turbidans acylase. When the pH of the reaction mixture was maintained at $6.20{\pm}0.04$, the reduction of the maximal conversion rate was not observed even with high enzyme loading. The kinetic parameters also suggest that pH drop during the enzymatic synthesis of cephalexin was mainly attributed to the rapid hydrolysis of D-${\alpha}$-phenylglycine methyl ester to D-${\alpha}$-phenylglycine, rather than the disappearance of 7-amino-3-deacetoxycephalosporanic acid for cephalexin synthesis. At higher molar ratio of two substrates, [D-${\alpha}$-phenylglycine methyl ester]/[7-amino-3-deacetoxycephalosporanic acid], the conversion rate was also elevated under pH-controlled enzymatic synthesis, which implies that the main reason for the pH drop is due to the production of D-${\alpha}$-phenylglycine methyl easter, the effect of a water-methanol cosolvent system on the ester, the effect of a water-methanol cosolvent system on the conversion profile was also examined. Even the though the conversion rate was increased in 10% methanol solution, a higher than 16% methanol in the reaction mixture caused an inactivation of enzyme.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1588-1594
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• 2012

An 8-wk experiment was conducted to evaluate the effect of replacing fish meal (FM) with soy protein isolate (SPI) on the growth, digestive enzyme activity and serum biochemical parameters of juvenile Amur sturgeon (Acipenser schrenckii). SPI was used to replace 0, 25, 50, 62.5, 75, 87.5, 100% of dietary FM and 100% replacement supplemented crystalline amino acid. Healthy sturgeon with an average initial weight of $26.38{\pm}0.24$ g were randomly assigned to 24 aquaria (8 treatments with triplicates each) at an initial stocking density of 11 fish per aquarium and cultured for 8 wks. The results showed that 75.00% or more substitution resulted in a poor weight gain rate, feed conversion ratio and survival rate compared to that of fish fed the control diet (p<0.05), whereas no significant differences were observed between diets of 25.00% to 62.50% substitution. Protease, lipase and amylase activity in foregut, mid-gut and hindgut were significantly (p<0.05) decreased by diets where SPI replacement levels were 62.50% or more. Levels of serum total protein (TP) and globulin decreased significantly from 21.03, 10.34 to 14.05, 5.63 g/L with the increasing dietary SPI (p<0.05), but alkaline phosphatase activity significantly increased (p<0.05). In addition, supplemental crystalline amino acid in the FM absence diet did not improve growth performance, intestine digestive enzyme activities and serum biochemical parameters. In conclusion, the results from this study showed adverse effects of inclusion of SPI in diets on growth performance, feed utilization and serum biochemical parameters in juvenile Amur sturgeon. Based on WGR and replacement ratio presented in this report, a 57.64% replacement level was recommended.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.364-369
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• 2013

Oxidative dehydrogenation of n-butane over mesoporous Cr catalysts were studied. Catalysts were prepared by Cr impregnated method over Ti or Zr dispersed mesoporous support such as SBA-15, ${\gamma}$-alumina and characterized by XRD, SEM, TEM, FT-IR UV-Vis and ICP-AES. The effect of high surface area was not noticed appreciably in terms of conversion, but for Cr catalysts with Ti and Zr-incorporated on SBA-15 and ${\gamma}$-alumina. showed high selectivity of trans-2-butene.

• Journal of Microbiology and Biotechnology
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• v.22 no.7
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• pp.967-974
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• 2012

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium-N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.