共表达伴侣蛋白对重组毕赤酵母产米根霉(Rhizopus oryzae)脂肪酶发酵过程的影响

Effect of co-expression of chaperones on Rhizopus oryzae recombinant lipase production in Pichia pastoris

【目的】通过共表达伴侣蛋白Ero1p和PDI获得米根霉(Rhizopus oryzae)脂肪酶在毕赤酵母中的高效表达。【方法】利用毕赤酵母基因重组菌高密度发酵的方法,在7 L发酵罐水平上分析共表达伴侣蛋白菌株(BH128)与非共表达伴侣蛋白菌株(H238)对脂肪酶表达的差异。【结果】在相同条件下,BH128发酵产酶能力高于H238,最高酶活可达到2 338.7 U/mL,最大比生长速率达到0.02 h 1,最大产物比形成速率达到944.5 U/(gDCW.h),最大底物比消耗速率也能达到0.15 gmethanol/(gDCW.h),分别是H238的1.7、0.5、4.1和1.3倍,且发酵周期缩短了20 h。【结论】毕赤酵母基因重组菌BH128通过共表达伴侣蛋白Ero1p和PDI,提高了米根霉脂肪酶的产量,而且缩短了发酵周期,为工业化生产奠定了基础。

[Objective] The aim of this study is to improve the yield of Rhizopus oryzae lipase http：//journals.im.ac.cn/wswxtbcn in Pichia pastoris by co-expression of chaperones.[Methods] By high-density fermentation in 7 L bioreactor,the expression of lipase in strain BH128 co-expressed with two chaperones Ero1p and PDI was compared with that of H238 co-expressed without any chaperone.[Results] The results showed that the highest lipase activity,the specific growth rate,the specific production rate and the specific consumption rate in BH128 reached 2 388.7 U/mL,0.02 h 1,944.5 U/（gDCW.h） and 0.15 gmethanol/（gDCW.h）,which is 1.7,0.5,4.1 and 1.3 fold higher than those in H238,respectively.Moreover,the fermentation period in BH128 was 20 hours shorter than in H238.[Conclusion] The high-level expression of Rhizopus oryzae lipase could be achieved by co-expression of chaperones Ero1p and PDI,which provided the potential application of Rhizopus oryzae lipase in industry.