利用玉米芯酸解液生产假单胞菌胞外多糖的研究

Production of Extracellular Polysaccharide from Hydrolysis of Corncob by Pseudomonas sp.

假单胞菌 (Pseudomonassp .)可利用玉米芯酸解液生长和产胞外多糖 ,其产品性能受玉米芯水解方法、发酵条件等的影响。在 12 1℃直接用稀酸水解玉米芯 3 0min ,产糖率高 ;用水预处理玉米芯后 ,再酸解 ,其水解液发酵所得多糖产量虽略低 ,但生物量稍高 ,且产品外观色泽均一。MnSO4 、FeSO4 和CaCl2 可明显提高发酵液的粘度。力学性能测试表明多糖粗制品在高浓度时为非牛顿流体 ;在pH值 2～ 12范围内粘度稳定 ;5 0℃加热 3 0min粘度不受影响。多糖制品无细胞毒性。在优化条件下发酵液最高粘度达 3 80 0mPa·s。

Pseudomonas sp.could grow in hydrolysis of corncob and produce a extracellular polysaccharide. The quality of the product was affected by hydrolysis methods of corncob and fermentation conditions. A higher yield of extracellular polysaccharide could be obtained by hydrolyzing corncob in a dilute acid for 30 minutes at 121?℃.The polysaccharide product from fermentation of hydrolysis was homogeneous color when the corncob was treated with water bath and then was acidolyzed. MnSO 4,FeSO 4 and CaCl 2 could improve the viscosity of fermentation liquid significantly. Rheology test showed that the raw product of concentrated polysaccharide had a pseudoplastic natare,which had a stable viscosity at pH 2～12 and its viscosity did not change when it was heated at 50?℃for 30 minutes. It also did not have cellular toxicity. The highest viscosity could each 3?800?mPa·s when the fermentation was performed under optimizing conditions.