Abstract: In order to seek the promoters efficiently expressing heterologous protein,the transcription functions of different promoters were evaluated using Enhanced Green Fluorescent Protein gene（egfp）as a reporter gene in Kluyveromyces lactis. Seven different promoters from K. lactis,Saccharomyces cerevisiae and Spathaspora passalidarum were cloned by PCR,fused to egfp respectively by overlap extension PCR and cloned into the reformed vector pKLAC1*. The recombinant expression plasmids were linearized by Bst XI and electro-transformed into K. lactis GG799. Further,the single-copy integrated recombinants regulated by different promoters were screened by PCR with specific primers,and the functions of different promoters were compared after qualitative and quantitative analysis of EGFP. The results of fluorescence microscopy showed that the expression of EGFP was regulated by the pKladh4 and pKlmal22 from K. lactis,pScgal7 and pScgpd1 from S. cerevisiae,as well as pSpmal1,pSpmal6 and pSpgal1 from S. passalidarum. The quantitative results of fluorospectrophotometer revealed that the fluorescence intensity of EGFP regulated by pKladh4,pScgal7 and pScgpd1 was 2.82,2.92 and 4.74,respectively;moreover,under the condition of the corresponding induction,the expression of EGFP was improved 13%,57% and 22%,respectively. These promoters were much stronger than pKllac4（2.13）that was the most widely used currently. Conclusively,this work probed the functions of promoters from different organisms in K. lactis,and the pKladh4,pScgal7 and pScgpd1 presented efficient initial transcription. It is the first time to report the application of pScgpd1 in K. lactis.

Key words: Kluyveromyces lactis, promoter, EGFP, single-copy integration, fluorescence intensity