Construction of a combinatorial protein library displayed on yeast cell surface and its application to molecular breeding

A combinatorial protein library was constructed which could be displayed on the cell surface of Saccharomyces cerevisiae by a multi-copy cassette vector. An improved method of DNA random priming was used to generate a large pool of random DNA fragments for increasing the variety. As one of the application, an organic solvent-tolerant yeast strain was obtained by screening of this library with n-nonane. Many organic solvents are highly toxic for living organisms because they accumulate in and disrupt cell membranes. Until now, there are few reports on eukaryotic organisms that can adapt to and survive these antimicrobial agents. The acquisition of nnonane-tolerance was proved to be due to the existence of transformed plasmids. The displaying of combinatorial libraries on yeast cell surface might open a novel door for molecular breeding of yeast.