Designer cellulosomes are synthetic multi-enzyme complexes that can degrade cellulosic biomass efficiently and economically. The goal of second generation biofuel production is to efficiently convert agricultural waste, algae and other cellulosic biomass into sugar monomers.Cellulosic biomass pretreated (e.g. with acid) under ideal conditions, still requires very high enzyme doses to provide efficient bioconversion. The cost of enzymes and pretreatment is a major hurdle in the production of low-cost cellulosic biofuel, competitive with that of fossil fuels or ethanol produced from corn or sugarcane. The complex structure of cellulosic materials is built to resist bacterial hydrolytic enzymes. The cooperation of many types of carbohydrate-active enzymes is required for effective degradation. By designing synthetic cellulosomes, researchers at The Weizmann Institute enhance synergy between carbohydrate-active enzymes to achieve remarkable degradation rates. Their discoveries can lead to highly efficient conversion of cellulosic biomass, and thus have a major impact in the field of food production and sustainable energy.
- High-yield, cost-effective conversion of plant cell wall biomass into soluble sugars for the food industry and the production of biofuels and biochemicals.
- Bio-engineered cellulosomes exhibit synergistic degradation activity of natural substrates compared to the combined action of the free wild-type enzymes.
The invention involves the conversion of enzymes (cellulases and xylanases) from the free mode to the cellulosmal mode by attachment using a recombinant dockerin molecule. The dockerin-bearing enzymes are incorporated into designer cellulosomes by interacting with a matching cohesion-containing chimeric scaffoldin (scaffoldin subunits contain the cohesin modules that incorporate the enzymes into the cellulosome complex via their resident dockerins). This approach has generated over two fold enhancement of synergistic hydrolysis on plant cell wall cellulosic biomass. These results create new possibilities for designing superior enzyme compositions for degradation of complex polysaccharides into simple soluble sugars.