Metagenomic cosmid libraries suitable for functional screening in proteobacteria

Abstract

Functional metagenomics, based on screening/selection of clones from metagenomic libraries, has the potential to make major contributions to our understanding of gene function and the development of biotechnology solutions. However, there are challenges and limitations that must be overcome if that potential is to be realized. These include cloning bias in library construction, host-dependence of gene expression, and library vector host range restrictions. In this chapter, we discuss some of our efforts to improve the quality and availability of metagenomic libraries through the production of a series of metagenomic cosmid libraries from diverse Canadian soils. Although these libraries are suitable for screening in a range of bacteria, they are currently limited to the Proteobacteria. To better capture genes from throughout the diversity of microbial life, it will be desirable to construct and make available metagenomic libraries that are able to support phenotypic screening in correspondingly suitable taxonomic backgrounds. Ongoing work is directed at achieving this important goal.