established biotechnology used worldwide, both to reduce waste biomass and to generate biogas
fuel. Under anaerobic conditions, complex and largely undefined consortia of microorganisms
depolymerize biopolymers and transfer the solar energy trapped by photosynthesis in these
molecules into intermediate fatty acids, alcohols and methylamines. In the terminal reactions,
methanogenic Archaea use hydrogen from fermentations to reduce carbon dioxide and methyl
groups from the intermediates to generate methane. An integrated effort is needed to expand the
application of anaerobes to a wider range of biomass and to construct microbial consortia that
most efficiently convert the biomass to natural gas.
RELEVANCE AND POTENTIAL IMPACT
Modification of the biochemistry of plants and bacteria, either genetically or through breeding,
along with an understanding of the mechanisms by which natural systems produce fuel, are
needed to improve the efficiency of such systems by a factor of 5–10 and to provide a convenient
fuel for end-use. The research directions identified here build upon advances in modern biology
by the broader biological research community that can be directed toward substantial
improvements in solar biofuels production. The new capabilities in computational chemistry,
structural biology, molecular machines, and nanotechnology that have become available only
recently will allow these ambitious goals to be reached.
REFERENCE
C. Somerville, S. Bauer, G. Brininstool, M. Facette, T. Hamann, J. Milne, E. Osborne, A.
Paredez, S. Persson, T. Raab, S. Vorwerk, and H. Youngs, “Toward a Systems Approach to
Understanding Plant Cell Walls,” Science 306 , 2206–2211 (2004).