蝉拟青霉多糖反馈抑制的初步研究

在摇瓶中考察了蝉拟青霉发酵菌丝体生长、多糖合成的动态过程,探讨了蝉拟青霉多糖自身反馈抑制作用。在培养144 h后,生物量达到最大值31.07 g/L;培养168 h后,蝉拟青霉多糖达到最高浓度3.24 g/L,大致与生物量变化的趋势呈正相关。在摇瓶培养基中添加同源多糖,以浓度梯度实验法考察培养基中的同源多糖浓度对蝉拟青霉菌丝体及多糖产量的影响。结果表明:当培养基中添加的同源多糖浓度大于0.6 g/L时,蝉拟青霉菌丝体及多糖的产生明显受到抑制,随着培养液中同源多糖浓度的增加,反馈抑制作用逐渐增强,当浓度达到2.2 g/L时,蝉拟青霉菌丝体的生长和多糖的产生完全被抑制。

A Preliminary Study on Feedback Inhibition of Polysaccharide in Paecilomyces cicadae

The feedback inhibition of polysaccharide in Paecilomyces cicadae was studied by investigating the dynamic process of Paecilomyces cicadae fermentation mycelium growth and polysaccharide synthesis in shake-flask culture.The biomass of P.cicadae reaches the maximum value(31.07 g/L) after 144 h culture,and the concentration of polysaccharide reaches the maximum value(3.24 g/L) after 168h culture and the polysaccharide concentration increases with increase of the biomass.The results show that the mycelium growth and polysaccharide synthesis of P.cicadae is apparently inhibited when over 0.6 g/L of homologous polysaccharide is added in liquid medium,the feedback inhibition effect increases with the increase of homologous polysaccharide concentration and the mycelium growth and polysaccharide synthesis of P.cicadae is completely inhibited when the concentration of homologous polysaccharide is higher than 2.2 g/L.