Functional characterization of an endoglucanase from Tribolium castaneum in Saccharomyces cerevisiae

Development of high-throughput functional assays for the screening of novel cellulases from insects is crucial to the identification of novel enzymes with applications for biofuel production. Our goal was to develop a functional assay to identify and characterize insect cellulases by expressing them in S. cerevisae cultures. We cloned the full-length cDNA encoding TcEG1, an endoglucanase from T. castaneum, in an expression vector containing the glyceraldehyde-3 phosphate dehydrogenase (GPD) promoter. This construct, p426-GPD-TcEG1, was then transformed into a strain of S. cerevisiae (TRY 127). Transformed clones were tested for cellulolytic activity on selective media plates containing Carboxymethyl Cellulose (CMC), as a glucose source. Recombinant yeast clones that were shown to produce TcEG1 allowed us to characterize its activity and level of expression. We propose to use this method for high throughput functional screening of novel cellulases from insect transcriptomes.