A biorefinery that supplements its manufacture of low value biofuels with high value biobased chemicals can enable efforts to reduce nonrenewable fuel consumption while simultaneously providing the necessary financial incentive to stimulate expansion of the biorefining industry. However, the choice of appropriate products for addition to the biorefinery's portfolio is challenged by a lack of broad-based conversion technology coupled with a plethora of potential targets. In 2004, the US Department of Energy (DOE) addressed these challenges by describing a selection process for chemical products that combined identification of a small group of compounds derived from biorefinery carbohydrates with the research and technology needs required for their production. The intent of the report was to catalyze research efforts to synthesize multiple members of this group, or, ideally, structures not yet on the list. In the six years since DOE's original report, considerable progress has been made in the use of carbohydrates as starting materials for chemical production. This review presents an updated evaluation of potential target structures using similar selection methodology, and an overview of the technology developments that led to the inclusion of a given compound. The list provides a dynamic guide to technology development that could realize commercial success through the proper integration of biofuels with biobased products.

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We have examined the relationships between primary, secondary, and tertiary structures of polysaccharides exhibiting the rheological property of friction (drag) reduction in turbulent flows. We found an example of an exopolysaccharide from the yeast Cryptococcus laurentii that possessed high molecular weight but exhibited lower than expected drag reducing activity. Earlier correlations by Hoyt showing that beta 1 --> 3, beta 2 --> 4, and alpha 1 --> 3 linkages in polysaccharides favored drag reduction were expanded to include correlations to secondary structure. The effect of sidechains in a series of gellan gums was shown to be related to sidechain length and position. Disruption of secondary structure in drag reducing polysaccharides reduced drag reducing activity for some but not all exopolysaccharides. The polymer from C. laurentii was shown to be more stable than xanthan gum and other exopolysaccharides under the most vigorous of denaturing conditions. We also showed a direct relationship between extensional viscosity measurements and the drag reducing coefficient for four exopolysaccharides.

Recent nontraditional biocatalytic techniques, particularly those which have involved introduction of enzymes into organic liquid phases, have revolutionized the way we think about biocatalysis. Within the past decade, a variety of research programs and open literature publications have arisen investigating nonaqueous enzyme activities and the potential for using such processes commercially. However, because of the wide variety of reaction and reactor types possible, as well as vague and easily misinterpreted terminology, it is often difficult to ascertain which reaction configurations are being studied and how these may be contrasted with similar research. We propose a systematic nomenclature and vocabulary such that reaction types can be quickly classified and compared with other nontraditional systems. The approach we have taken to distinguish between systems is primarily dependent upon the phase in which each of the critical reaction components (biocatalyst, reactant(s), and product(s) ) is present. Possible resident phases include aqueous (A), organic (O), vapor (V), and supercritical (SC) . With this system, a reaction scheme may be classified with a three‐character identifier, such as AAO (a system in which the enzyme and substrate are present in an aqueous phase and the product is recovered from an organic phase) . Special cases, such as when the biocatalyst is immobilized or the product forms an insoluble precipitate, are also discussed in the context of this nomenclature. This developed nomenclature and vocabulary also allow categorization of biocatalytic bioprocessing into two distinct classes: traditional (aqueous phase only) and nontraditional, the latter of which may be further subdivided into nonaqueous, aqueous, and supercritical biocatalysis. Such categorization provides a cohesive methodology by which to classify new work within the nontraditional arena, as well as to broaden or refine current research. Furthermore, this paper provides a technology roadmap which outlines nontraditional areas and their associated development issues which still require examination, in terms of both bridging and fundamental research, before these techniques will be adopted by the private sector.

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