The current shortages and high prices of gasoline products are making it clear that a sustainable, economical, and environmentally benign process for producing fuel is needed. In the future, lignocellulosic-derived products are poised for sharp growth. According to a recent McKinsey report, the bio-based products market is expected to exceed $182.91 billion by 2015 [34]. Lignocellulosic-derived products may play a pivotal role to match this expectation and future markets seem very promising for ethanol, xylitol, organic acids, and 2, 3-BD. Mechanisms for higher yield and productivity of these value-added products can be developed by exploring the hemicellulose fraction of the cell wall in depth.

The fermentation of pentose sugars is not as easy as that of cellulosic-derived hexose sugars due to the unavailability of appropriate microorganisms and the lack of an established bioconversion process. In-depth studies of methods for hemicellulosic degradation are required. This will assist in limiting the role of fer­mentation inhibitors during hemicellulosic degradation. In the past five years, there has been substantial development in the area of hemicellulose hydrolysis using rou­tine methodologies with known microorganisms. A newer approach to hydrolyzing technologies using a battery of hemicellulase titers needs to be developed to pro­duce high yields of sugar monomers and eventually convert them into value-added products. Isolation and screening of potent hemicellulase-producing microorgan­isms and further development of mutants/cloned microorganisms may improve the production yields of the desired titers on a commercial scale. Genetic engineering may also improve microbial efficiency for the overproduction of industrial prod­ucts using cheaper sources of carbohydrates in fermentation media, the hallmark of commercial fermentation processes. The microbes will be more useful if they have characteristics such as thermotolerance, alkalotolerance, or tolerance of other extreme conditions.

Hemicellulose degradation into fermentable sugars is another area where the scope of research seems enormous. Efforts are underway at our laboratory for the production of ethanol and xylitol from lignocellulose feedstock. Multiple research projects are being sponsored by government agencies to improve the pretreatment process of lignocellulosics for their conversion into ethanol and xylitol [24, 63-69].

In the last five years, there has been comparatively less research into 2, 3-BD pro­duction than into ethanol and xylitol production worldwide. New research insights, such as the development of transgenic plants containing less lignin, may be help­ful for the conversion of biomass into value-added products. Chen and Dixon [70] developed antisense-mediated down-regulation of lignin biosynthesis in alfalfa to reduce or eliminate the need for pretreatment. This may make the hemicellulosic fraction more accessible due to the reduced presence of lignin, which in turn will require a milder pretreatment and less enzymatic load to get the desired yield of fermentable sugars. Releasing genetically engineered plants may raise ethical issues among environmentalists; however, it can be assumed that the generation of new products from hemicellulose will strengthen the economy by saving for­eign exchange reserves and promoting energy independence, which will benefit the environment.