初始pH值对细脚拟青霉小试发酵过程及胞内核苷积累的影响

在30L发酵罐中，采用液体深层发酵的方法，考察培养液初始pH7、6.5、6、5.5、5、4.5时对细脚拟青霉菌体生长及胞内核苷类物质积累的影响。结果表明：初始pH6.5时，对菌体生长和胞内核苷的积累最为有利，最大生物量为28.7g/L，最高胞内核苷类物质产量为5.94mg/g；起始pH7、6、5.5、5、4.5时，最大生物量分别在发酵的第9、10、11、11、13天获得，依次为26.4、27.3、23.6、21.2、18.5g/L；最大胞内核苷类物质的产量分别在发酵的第11、11、11、13、13天获得，依次为5.27、5.51、4.89、4.29、4.05mg/g。细脚拟青霉以菌体或者胞内代谢物为发酵目标进行优化控制时，其发酵初始pH值应调节到相应的最佳值。

Effect of Initial pH on Mycelial Growth and Intracellular Nucleoside Production of Paecilomyces tenuipes in a 30 L Fermentor

Effect of initial pH on the mycelial growth and intracellular nucleoside production of Paecilomyces tenuipes was studied in a 30 L fermentor during submerged fermentation. The results showed that the optimal initial pH was 6.5. The maximal biomass reached up to 28.7 g/L and the maximal nucleoside production was up to 5.94 mg/g. The maximal biomasses corresponding to different initial pH values such as 7, 6, 5.5, 5 and 4.5 were 26.4, 27.3, 23.6, 21.2 mg/g and 18.5 mg/g, respectively, which were achieved on the 9th, 10th, 11th, 11th days and 13th days of fermentation and the corresponding maximal nucleoside production was 5.27, 5.51, 4.89, 4.29 mg/g and 4.05 mg/g, respectively, which was observed on the 11th, 11th, 11th, 13th days and 13th days. Therefore, the best mycelial growth intracellular nucleoside production could be achieved by initial pH adjustment.