State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China.
Biotechnol Lett. 2010 Apr;32(4):507-12. doi: 10.1007/s10529-009-0182-3. Epub 2009 Dec 16.
Inulinase gene (Kcinu) derived from Kluyveromyces cicerisporus was expressed extracellularly in Kluyveromyces lactis using an episomal vector directed by Kcinu promoter. The influence of hap1 gene disruption on the expression of inulinase was studied. Inulinase activity in the supernatant of the recombinant Klhap1Delta strain was 391 U ml(-1) after cultured 120 h, which was 2.2-fold that of the wild type host. The relative inulinase mRNA level of the Klhap1Delta strain was 11.3-fold that of the wild type strain, and the expression plasmid was more stable in the mutant host. Based on these results, the disruption of hap1 facilitated the high and stable expression of inulinase controlled by Kcinu promoter in K. lactis.
菊粉酶基因（Kcinu）来源于克里维酵母（Kluyveromyces cicerisporus），通过 Kcinu 启动子指导的附加体载体在乳酸克鲁维酵母（Kluyveromyces lactis）中实现了胞外表达。研究了 hap1 基因缺失对菊粉酶表达的影响。重组 Klhap1Delta 菌株培养 120 h 后，上清液中的菊粉酶活性为 391 U ml(-1)，是野生型宿主的 2.2 倍。Klhap1Delta 菌株的相对菊粉酶 mRNA 水平是野生型菌株的 11.3 倍，而且突变宿主中表达质粒更加稳定。基于这些结果，hap1 的缺失有利于 Kcinu 启动子控制的菊粉酶在 K. lactis 中的高效和稳定表达。
