Diverse concepts for the use of lignocellulose-containing plants for bioethanol production are available. In the simplest concept, only the glucose is fermented to bioethanol, with the by-products xylose solution and lignin pellets. The xylose sugars can be used as barrier films, hydrogels, paper additives (Soderqvist et al., 2001; Lima et al., 2003; Gronholm et al., 2004) or in xylitol production (reviewed in Chen et al., 2010). At the moment, the utilization of lignin is unsatisfactory; therefore, the lignin pellets are used as solid biofuel.

The economy of bioethanol production from lignocellulose-containing materials can be improved in a cost-effective concept by simultaneous fermentation of both sugars (glucose and xylose) to bioethanol by diverse microorganisms. In the last twenty years, diverse microorganisms were genetically modified to ferment both glucose and xylose, with good results (reviewed in Hahn-Hagerdal et al., 2007; Matsushika et al., 2009; Jojima et al., Kim et al., Mussatto et al., Weber et al, Young et al., 2010). Furthermore, diverse adaptation programs, mutagenesis and breeding were performed to produce yeasts and other microorganisms with improved xylose fermentation (reviewed in Hahn-Hagerdal et al., 2007; Matsushika et al., 2009; Mussatto et al., 2010). However, in several countries production with GMO is only possible under strict standards and acceptance of GMO in these countries is poor.

In a biorefinery concept, co-production of biofuels, bioenergy and marketable chemicals from renewable biomass sources take place simultaneously. Diverse biorefinery concepts for wheat straw were developed such as: bioethanol from glucose, biohydrogen from xylose and the residual effluents from bioethanol and biohydrogen processes being used for biogas production (Kaparaju et al., 2009). The biorefinery concept including higher-value chemical by-products and autonomous power supplies will enhance economic competitiveness of second generation plants and, therefore, will make this type of plant economical in the near future.