Screening for microbial enzymes towards bioethanol production and biorefinery applications by quantitative proteomics approach.

Abstract

Biorefinery of lignocellulosic biomass to produce bioethanol is a promising renewable energy source, but low efficiency of industrial enzymes is the current limitation. I applied an iTRAQ - based high throughput quantitative proteomics method by employing Thermobifida fusca as model organism to screen for lignocellulolytic proteins. My aims are to get a better understanding of bacterial lignocellulolytic system as well as to identify the novel lignocellulolytic enzymes, on the belief that these findings are helpful in improving the enzymatic efficiency of current biorefinery approaches. This study identified a significant number of secretory lignocellulolytic enzymes previously reported, which provide clues in constructing an overall picture of T. fusca lignocellulolytic system. Also, my membrane proteome result suggested that T. fusca might employ a survival strategy to exploit more energy sources when encountering lignin-containing starved condition. Notably, six uncharacterized and hypothetical lignocellulolytic-involving proteins were identified. Supplemented with sufficient validating evidences and further characterization studies, these proteins could be useful towards bioethanol production and biorefinery applications.