SBIR Phase I: Engineering Hydrolytic Enzymes for Enhanced Sugar Recovery From Biomass

This Small Business Innovation Research Phase I project aims to apply Protabit?s state-of-the-art computational protein design (CPD) platform to engineer a more thermostable and cost-effective set of lignocellulosic enzymes for converting biomass to simple sugars. CPD is an innovative technology that yields enzymes with novel or enhanced properties that cannot be found using traditional protein engineering methods, and Protabit is actively developing the most advanced, commercial-grade CPD platform available. In Phase I, Protabit and the Mayo Lab at the California Institute of Technology will stabilize two important commercial cellulases, H. jecorina Cel5A and Cel7A. The objectives of Phase I are: (a) to apply CPD to design libraries of thermostable Cel5A and Cel7A variants, and to use high-throughput screening to identify variants with optimal cellulolytic activity at elevated temperatures; (b) to measure the degree to which the most active thermostable variants reduce enzyme loading and hydrolysis time on pretreated corn stover, and to estimate the corresponding cost savings; and (c) to characterize the most active thermostable variants for other commercially important properties such as pH profile and expression yield. In Phase II, Protabit and Caltech will similarly engineer other key lignocellulosic enzymes and optimize this core set for activity on corn stover, switchgrass, and other biomass feedstocks. The broader impacts/commercial potential of this research are: (a) to reduce the costs of converting biomass into glucose and other simple sugars, which are a principal raw material input in the rapidly growing renewable fuels and chemicals industries, and (b) to demonstrate Protabit's versatile protein engineering platform technology on a specific problem of commercial significance in industrial biotechnology. By facilitating the bio-based production of advanced drop-in biofuels, ethanol, and precursors for synthetic rubber, plastics, and other petroleum-derived materials, this research can help reduce U.S. dependence on foreign oil and spur domestic manufacturing, investment, and job creation. In addition, sourcing sugars from cellulose, the most abundant polymer on the planet, can curb the food-versus-fuel debate by reducing demand for edible corn as a biofuels feedstock; it also encourages the farming of dedicated feedstock crops capable of growing on marginal lands unsuitable for food production. Furthermore, CPD-based protein stabilization methods enable new products and technologies in myriad areas, including industrial enzymes, protein materials, novel antibody-like scaffolds, and therapeutics with improved shelf-life or biological half-life. With this project, Protabit and Caltech will help the U.S. take a major step toward economic, energy, and environmental security.