【摘要】 γ聚谷氨酸是一种生物可降解的高分子材料,可应用于多种领域,因此受到普遍重视。报道了以11株枯草芽孢杆菌菌株为培养菌株,用3种谷氨酸钠含量不同的培养基进行筛选获得1株γ聚谷氨酸高产菌株;再以该菌株为研究对象进行碳源、氮源、谷氨酸钠浓度、初始pH、接种量、通气量等发酵条件的优化实验,结果表明最佳发酵条件为:250ml三角烧瓶装液40ml,接种体积分数5%,麦芽糖50g/L,酵母膏10g/L,谷氨酸钠30g/L,NaCl10g/L,KH2PO45g/L,MgSO4·7H2O0.5g/L,初始pH6.0,发酵60h,此时γ聚谷氨酸产量最高,达到30.26g/L,比国外报道的20g/L的产量有显著提高。纯化后产物经红外光谱及核磁共振检测,鉴定为γ聚谷氨酸。更多还原

【Abstract】 Poly-γ-glutamic-acid is a biodigested high molecular material which can be used in many ways. A high-productive poly-γ-glutamic-acid strain from 11 Bacillus strains was screened by culturing in three different mediums. In order to enhance the production of this strain, we optimized the fermentation conditions, such as carbon source, nitrogen source, concentration of sodium glutamate, initial pH, inoculation size. The result showed that the optimal medium is maltose 50 g/l, yeast 10g/l, sodium glutamate 30g/l, NaCl 10g/l,KH2PO4 5g/l,MgSO4·7H2O 0.5g/l (initial pH 6.0) .The strain was cultivated in a 250ml flask containing 40ml such medium, with the inoculate quantity of 5%, for 60h. Then the production of poly-γ-glutamic-acid reached 30.26g/l. The productivity of poly-γ-glutamic-acid is obviously improved than 20g/l reported by overseas. To confirm the product is poly-γ-glutamic-acid, Fourier Transform Infrared Spectroscopy and H1- and C 13- NMR were used to test purified product, the results were consistent with the standard sample.更多还原