Combinatorial Screening for Transgenic Yeasts with High Cellulase Activities in Combination with a Tunable Expression System

PLoS One

Chie Imamura¹  Akinori Ikeuchi¹  Takashi Matsuyama²  Mamoru Yamanishi²  Yoichiro Ito² 

[1] Biotechnology Laboratory, TOYOTA Central Research and Development Laboratories Incorporation, Nagakute, Aichi, Japan;Matsuyama Research Group, TOYOTA Central Research and Development Laboratories Incorporation, Nagakute, Aichi, Japan

关键词: Cellulases;    Yeast;    Ethanol;    Cellulose;    Polymerase chain reaction;    Protein expression;    Genetic screens;    Gene expression;   

DOI  :  10.1371/journal.pone.0144870

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

Combinatorial screening used together with a broad library of gene expression cassettes is expected to produce a powerful tool for the optimization of the simultaneous expression of multiple enzymes. Recently, we proposed a highly tunable protein expression system that utilized multiple genome-integrated target genes to fine-tune enzyme expression in yeast cells. This tunable system included a library of expression cassettes each composed of three gene-expression control elements that in different combinations produced a wide range of protein expression levels. In this study, four gene expression cassettes with graded protein expression levels were applied to the expression of three cellulases: cellobiohydrolase 1, cellobiohydrolase 2, and endoglucanase 2. After combinatorial screening for transgenic yeasts simultaneously secreting these three cellulases, we obtained strains with higher cellulase expressions than a strain harboring three cellulase-expression constructs within one high-performance gene expression cassette. These results show that our method will be of broad use throughout the field of metabolic engineering.

【 授权许可】

CC BY