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Significance In recent years there has been extensive research toward the development of sustainable polymeric materials. However, environmentally benign, bioderived polymers still represent a woefully small fraction of plastics and elastomers on the market today. To displace the widely useful oil-based polymers that currently dominate the industry, a bioderived synthetic polymer must be both cost and performance competitive. In this paper we address this challenge by combining the efficient bioproduction of β-methyl-δ-valerolactone with controlled polymerization techniques to produce economically viable block polymer materials with mechanical properties akin to commercially available thermoplastics and elastomers.

Conversion of lignocellulosic biomass into value-added products provides important environmental and economic benefits. Here we report the engineering of an unconventional metabolism for the production of tricarboxylic acid (TCA)-cycle derivatives from D-xylose, L-arabinose and D-galacturonate. We designed a growth-based selection platform to identify several gene clusters functional in Escherichia coli that can perform this nonphosphorylative assimilation of sugars into the TCA cycle in less than six steps. To demonstrate the application of this new metabolic platform, we built artificial biosynthetic pathways to 1,4-butanediol (BDO) with a theoretical molar yield of 100%. By screening and engineering downstream pathway enzymes, 2-ketoacid decarboxylases and alcohol dehydrogenases, we constructed E. coli strains capable of producing BDO from D-xylose, L-arabinose and D-galacturonate. The titers, rates and yields were higher than those previously reported using conventional pathways. This work demonstrates the potential of nonphosphorylative metabolism for biomanufacturing with improved biosynthetic efficiencies.

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