ABSTRACT
Objective To construct a prokaryotic expression vector in BL21 to secretorily expressα-Cyclodextrin Glycosyltransferase(α-CGTase). Methods α-CGT gene was amplified from Bacillus macerens genome by PCR.pET26b and α-CGT gene were connected after digested with Nco I, Xho I respectivly, and then transformed into Escherichia coli BL21 strain.α-CGTase was expressed in fermentation culture medium and AA-2G was prepared by using α-CGTase, VC and starch.Results α-CGTase was expressed secretorily and the enzyme activity was up to 120 U/mL.AA-2G was prepared by the biotransformation of VC and starch using α-CGTase which proved to be correct by HPLC.Conclusion AA-2G was prepared by using self-madeα-CGTase, after optimized the preparation conditions the yield of AA-2G was 17.46 g/L, and the conversion rate reached 58.2%(mg/mg).
ABSTRACT
Objective To develop a gel permeation chromatography method for determination of content and molecular weight ( Mw ) of Mussel Polysaccharide.Methods Using GPC method, the sample was separated with TSK-gel GMPWXL(7.8 mm ×300 mm) chromatography column which was set at 35℃.The mobile phase was 0.05 mol/mL NaNO3(including 0.05%Na2N3) and the flow rate was 0.6 mL/min.The detector was RID-20AT. Results The average molecular weight of the polysaccharide of Mytilus coruscus was 1 261 411 and the average content was 88.6%by using of the calibration curves of dextrans.The average molecular weight of the polysaccharide of Mytilus edulis was 1 244 062 and the average content was 87.4%. Conclusion The method established in this paper is simple and rapid, accurate and reproducible, which can be used for the quality control of Mussel Polysaccharide.