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A continuous production of fructooligosaccharides from sucrose was investigated by fructosyltransferase immobilized on a high porous resin, Diaion HPA 25. The optimum pH (5.5) and temperature (55°C) of the enzyme for activity was unaltered by immobilization, and the immobilized enzyme became less sensitive to the pH change. The optimal operation conditions of the immobilized enzyme column for maximizing the productivity were as follows: 600 g/L of sucrose feed concentration, flow rate of superficial space velocity 2.7 h?1. When the enzyme column was run at 50°C, about 8% loss of the initial activity of immobilized enzyme was observed after 30 days of continuous operation, during which high productivity of 1174 g/L·h was achieved. The kinds of products obtained using the immobilized enzyme were almost the same as those using soluble enzymes or free cells. 相似文献
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Theoretical calculation of the sugar concentrations during enzymatic production of fructooligosaccharides 总被引:1,自引:0,他引:1
Summary In a batch production of fructooligosaccharides from sucrose, the concentrations of residual sucrose, glucose and fructooligosaccharides at a given reaction time(t) and initial sucrose concentration(S0) were theoretically calculated by the following correlation equations: Glucose(t) = 0.0653 S0 × ln(t); Fructooligosaccharides(t) = 0.1636 S0 × ln(t); Sucrose(t)=S0 - Glucose(t) + FOS(t). 相似文献
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Won S. Woo 《Phytochemistry》1974,13(12):2887-2889
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Stoichiometries, equilibrium constants and optical extinction coefficients of calcium-antipyrylazo III (An) complexing are determined with the analytical method described in article I of this series. Spcctrophotometric Ca titrations of An at the wavelengths 595 and 710 nm indicate overall dissociation equilibrium constants for the complexes CaAn, CaAn2 and Ca2An to be 4.5 × 10?4 M, 1.1 × 10?8 M2 and 1.5× 10?6 M2, respectively, extrapolated to zero ionic strength. Ca titrations of solutions containing An plus acetylcholine receptor protein give clear evidence that An binds to the protein to a large extent in the presence of Ca2+; furthermore, addition of acetylcholine results in release of protein-bound Ca and An. This is the first reported indication that antipyrylazo III binds to biological material and questions the usefulness of this dye as a Ca indicator in biological systems. 相似文献
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Won Jae Choi 《Applied microbiology and biotechnology》2009,84(2):239-247
Enantiopure epoxides are high value-added synthons for the production of pharmaceuticals, agrochemicals, as well as versatile
fine chemicals and have broad scope of market demand for their applications. A major challenge in conventional organic synthesis
is to generate such compounds in high enantiopurity with reasonable yield. Among possible chemical and biological technologies
for enantiopure epoxide preparation, enzymatic kinetic resolution has been paid much attention with respect to its high enantioselectivity.
Epoxide hydrolase (EH) has shown promising characteristics for the preparation of enantiopure epoxides and vicinal diols during
enantioselective hydrolysis of racemic epoxides. EH is readily available from microbial resources thus it is being employed
for biohydrolysis of a variety of epoxides. Recent technical progress in EH-catalyzed enantioselective hydrolysis is summarized
in terms of exploration of novel EH, its functional improvement, high throughput assay, and preparative scale resolution process. 相似文献
7.
Seunghun Lee Won Yeong Park Hoonchul Chang Bumju Kim Won Hyuk Jang Seonghan Kim Younghoon Shin Myoung Joon Kim Kyung Hwa Lee Eui Hyun Kim Euiheon Chung Ki Hean Kim 《Journal of biophotonics》2020,13(1)
Delineation of brain tumor margins during surgery is critical to maximize tumor removal while preserving normal brain tissue to obtain optimal clinical outcomes. Although various imaging methods have been developed, they have limitations to be used in clinical practice. We developed a high‐speed cellular imaging method by using clinically compatible moxifloxacin and confocal microscopy for sensitive brain tumor detection and delineation. Moxifloxacin is a Food and Drug Administration (FDA) approved antibiotic and was used as a cell labeling agent through topical administration. Its strong fluorescence at short visible excitation wavelengths allowed video‐rate cellular imaging. Moxifloxacin‐based confocal microscopy (MBCM) was characterized in normal mouse brain specimens and visualized their cytoarchitecture clearly. Then, MBCM was applied to both brain tumor murine models and two malignant human brain tumors of glioblastoma and metastatic cancer. MBCM detected tumors in all the specimens by visualizing dense and irregular cell distributions, and tumor margins were easily delineated based on the cytoarchitecture. An image analysis method was developed for automated detection and delineation. MBCM demonstrated sensitive delineation of brain tumors through cytoarchitecture visualization and would have potentials for human applications, such as a surgery‐guiding method for tumor removal. 相似文献
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