One significant obstacle impeding the large scale production of fuels and chemicals from cellulosic biomass is the lack of a low cost processing technology. The conventional biochemical platform for biorefinery involves five distinct steps: pretreatment, cellulase production, enzymatic hydrolysis, fermentation, and product recovery. Sugars are produced as the reactive intermediate for the subsequent fermentation. Steps involved with overcoming the recalcitrance of cellulosic biomass (pretreatment, cellulase production, and enzymatic hydrolysis) are the three most costly steps in the whole process. Here we propose a novel biochemical platform for fuels and chemical production that will replace the three most costly steps in the conventional platform with a single biological step. Cellulolytic microorganism(s) that can secrete all the enzymes needed to hydrolyze cellulose and hemicellulose in spite of the presence of lignin will be modified to convert most of the carbohydrate contained in the cellulosic biomass to sugar aldonates. In a second step, sugar aldonates will be utilized as the carbon source to produce ethanol and other products. The new platform can potentially lower the cost of cellulosic bioprocessing substantially. Factors contributed to the cost reduction include elimination of the high capital cost and high operating cost associated with thermo-chemical pretreatment process, consolidation of the process, and reduction of the product recovery cost due to potential higher ethanol concentrations produced in the fermentation step.