添加辅酶前体及流加诱导物提高黄嘌呤氧化酶发酵产率

通过对产黄嘌呤氧化酶菌株进行16S rDNA序列分析,构建系统进化树,确定该菌株为球形节杆菌(Arthrobacter globiformis)。添加辅酶前体(核黄素、硫胺素)及诱导物(次黄嘌呤,3.6 g/L),提高了发酵产酶;通过两种方式流加葡萄糖及次黄嘌呤,结果表明,发酵至24 h,一次性补葡萄糖质量浓度4.0 g/L,流加次黄嘌呤质量浓度至3.6 g/L,酶产率可达8 952.7 U/L,比未补料时提高25.7%,平均产率系数达1 041.0 U/g。测定流加发酵过程中铵根离子浓度变化,发现一定质量浓度的铵根离子抑制发酵产黄嘌呤氧化酶。

Enhancing the Production of Xanthine Oxidase by Adding Precursors of Coenzyme and Feeding Inducer

Based on sequence analysis of 16S rDNA and construction of phylogenetic trees, xanthine oxidase-producing strain in this work was identified as Arthrobacter globiformis. Xanthine oxidase(XOD) production was first enhanced by adding precursors of coenzyme(riboflavin and thiamine) and inducer(hypoxanthine, 3.6 g/L). In order to relieve inhibition for XOD production caused by hypoxanthine, two types of feeding protocols were investigated. The result indicated that feeding hypoxanthine to 3.6 g/L and adding 4.0 g/L glucose from 24 h made the XOD production achieved to 8 952.7 U/L, increased by 25.7%. And the average yield coefficient reached to 1041.0 U/g. It was found that high concentrations of ammonia(the end production of purine degradation) inhibited the xanthine oxidase fermentation.