S160: Engineering the filamentous fungus Trichoderma to produce an optimized mixture of recombinant and wild type proteins to make 2nd generation biomass conversion a reality

Trichoderma and filamentous fungi are the most important high yielding production hosts for eukaryotic proteins. The majority of commercial enzyme products for biomass hydrolysis are produced by the saprophytic mesophilic fungus Trichoderma reesei.  Trichoderma produces two cellobiohydrolases (CBHI and CBHII), five endoglucanases (EGs), and two β-glucosidases (BGs).  This mix of enzymes is relatively efficient at cellulose degradation and large quantities of these proteins are secreted from the fungus.  However, compared with starch hydrolysis, 15-100 fold more enzyme is required to produce an equivalent amount of ethanol, depending on specific process conditions.  Novozymes has been working for many years to reduce the amount and subsequent cost of enzymes required for efficient hydrolysis of lignocellulosic biomass. We have approached this from several perspectives: increasing the specific activity of the enzymes present in our existing cellulase products, adding accessory proteins that improve performance on some substrates; and increasing the productivity of our production strains. We have demonstrated that many of the enzymatic components produced by T. reesei, while generally of high quality, can be significantly outperformed by homologous proteins from other species. Furthermore, most of these superior proteins can be expressed at appropriate levels in our latest generation of high-yielding T. reesei production strains. We will present the results of our enzyme improvement efforts and show that the cellulase/hemicellulase products introduced into the market in 2010 are significantly improved over our current Cellic™ products. We will also show that the 2010 products can be further improved by addition of specific monocomponent proteins.