Production ofD-Xylonic Acid from Hemicellulose Using Artificial Enzyme Complexes.
Lignocellulosic biomass represents a potentially large resource to supply the world's fuel and chemical feedstocks. Enzymatic bioconversion of this substrate offers a reliable strategy for accessing this material under mild reaction conditions. Owing to the complex nature of lignocellulose, many different enzymatic activities are required to function in concert to perform efficient transformation. In nature, large multienzyme complexes are known to effectively hydrolyze lignocellulose into constituent monomeric sugars. We created artificial complexes of enzymes, called rosettazymes, in order to hydrolyze glucuronoxylan, a common lignocellulose component, into its cognate sugarD-xylose and then further convert theD-xylose intoD-xylonic acid, a Department of Energy top-30 platform chemical. Four different types of enzymes (endoxylanase, α-glucuronidase, β-xylosidase, and xylose dehydrogenase) were incorporated into the artificial complexes. We demonstrated that tethering our enzymes in a complex resulted in significantly more activity (up to 71%) than the same amount of enzymes free in solution. We also determined that varying the enzyme composition affected the level of complex-related activity enhancement as well as overall yield.
USDA-ARS-WRRC, Bioproducts Research Unit, Albany, CA 94710, USA.
Charles C
CC
Lee
USDA-ARS-WRRC, Bioproducts Research Unit, Albany, CA 94710, USA.
Rena E
RE
Kibblewhite
NASA Ames Research Center, Moffett Field, CA 94035, USA.
Chad D
CD
Paavola
USDA-ARS-WRRC, Bioproducts Research Unit, Albany, CA 94710, USA.
William J
WJ
Orts
USDA-ARS-WRRC, Bioproducts Research Unit, Albany, CA 94710, USA.
Kurt
K
Wagschal
Lignocellulose; bioconversion; glucuronoxylan; multienzyme assembly; xylonic acid