不同渗透压调节剂对Candida krusei生理代谢的影响

比较了氯化钠、氯化钾、甘露醇存在的高渗环境下克鲁氏假丝酵母(Candida kru-sei)的生理代谢。3种渗透压调节剂对C.krusei生理代谢影响有显著差异。与甘露醇相比,氯化钠和氯化钾对细胞生长的影响更为显著,而氯化钾对细胞的毒性则又小于氯化钠。细胞对糖的消耗速率依次为甘露醇>氯化钾>氯化钠。甘油和海藻糖是C.krusei在高渗环境下的主要相容性溶质。氯化钠和氯化钾对甘油合成的促进作用明显高于甘露醇。在0.6mol/L氯化钠、氯化钾、甘露醇存在时,细胞甘油浓度较对照提高了74%、63%、57%;胞内甘油最大含量也分别达到对照的3.1,2.4和1.8倍。高渗环境下胞内海藻糖含量在发酵前期均有所降低,但发酵后期在0.6mol/L氯化钾和甘露醇存在时海藻糖迅速积累,其含量分别达对照的1.6和1.4倍。

Effect of Different Osmotica on the Metabolism of Candida krusei

The metabolism of Candida krusei was compared in different osmotic conditions by using NaCl,KCl and manntiol as osmotica.The significant different metabolism of C.krusei at different osmotic stress was observed.NaCl and KCl affected the cell growth much more than manntiol.Furthermore,NaCl was more toxic than KCl to C.krusei cell.The sugar consumption rate of the cell from high to low was manntiol>KCl>NaCl.Glycerol and trehalose were the most prominent compatible solutes in C.krusei.The glycerol production was enhanced with the osmotica concentration increasing and NaCl,KCl were much effective than manntiol.The glycerol concentration was increased 74%,63%,57% and the intracellular glycerol was 3.1,2.4,1.8 fold to the control respectively when 0.6mol/L NaCl,KCl and mannitol existed.During the early stage of fermentation,the trehalose all decreased compared with the control.However,the trehalose content was higher than the control in the late stage of fermentation when 0.6mol/L KCl and mannitol existed.The trehalose content was 1.6 and 1.4 fold to that of control respectively.