^{During the past 3 decades after the first oil crisis a large community has been working in this field and especially the past 2 decades metabolic engineering techniques have been established to improve capabilities in developing advanced organisms for enzyme production using filamentous fungi as well as ethanol production using the industrially most proven yeast Saccharomyces cerevisiae. In the past decade, researchers have sequenced the whole genome of Saccharomyces cerevisiae and have demonstrated conversion of xylose and/or arabinose simultaneously with glucose by using metabolic engineering of yeast. Furthermore, the technology has emerged from research into development phase taking cellulosic ethanol a step closer to commercial realization.}

^{DSM has now developed an industrial advanced yeast using a robust Saccharomyces cerevisiae host that was engineered to enable the conversion of the most abundant biomass sugars glucose, xylose, arabinose, galactose and mannose at high yield to ethanol.} 

^{Overall process design considerations from feedstock to final products will be discussed, including feedstock compositions, pretreatment, hydrolsyis, fermentation and down stream processing issues for ethanol and byproducts.}