Novozymes has been working for many years to reduce the cost of enzymes required to hydrolyze lignocellulosic biomass. We have approached this from several perspectives: Increasing the specific activity of the enzymes present in our existing cellulase products (improving the “weak links”); addition of  accessory proteins that improve performance on some substrates (addition of “missing links”); and increasing the productivity of our production strains. In addition, we have addressed the interaction between pretreatment, enzymatic hydrolysis and fermentation in order to attain a holistic view of the entire process and its associated costs. Our search for missing links and weak links in our cellulase products has employed a survey of several thousand species of bacteria and fungi and the cloning, expression, and analysis of more than 500 genes from a wide diversity of organisms. We have demonstrated that many of the enzymatic components produced by Trichoderma 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 that will be 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.