By applying metabolic engineering tools and strategies to engineer synthetic enzyme pathways, the number and diversity of commodity and specialty chemicals that can be derived directly from renewable feedstocks is rapidly and continually expanding. This of course includes a number of monomer building-block chemicals that can be used to produce replacements to many conventional plastic materials. This review aims to highlight numerous recent and important advancements in the microbial production of these so-called “biomonomers.” Relative to naturally-occurring renewable bioplastics, biomonomers offer several important advantages, including improved control over the final polymer structure and purity, the ability to synthesize non-natural copolymers, and allowing products to be excreted from cells which ultimately streamlines downstream recovery and purification. To highlight these features, a handful of biomonomers have been selected as illustrative examples of recent works, including polyamide monomers, styrenic vinyls, hydroxyacids, and diols. Where appropriate, examples of their industrial penetration to date and end-product uses are also highlighted. Novel biomonomers such as these are ultimately paving the way toward new classes of renewable bioplastics that possess a broader diversity of properties than ever before possible.
Keywords: bioplastics, biopolymers, monomers, metabolic engineering
Citation: Adkins J, Pugh S, McKenna R and Nielsen DR (2012) Engineering microbial chemical factories to produce renewable “biomonomers”. Front. Microbio. 3:313. doi: 10.3389/fmicb.2012.00313
Received: 04 June 2012; Accepted: 08 August 2012;
Published online: 30 August 2012.
Edited by:Weiwen Zhang, Tianjin University, China
Reviewed by:Kesaven Bhubalan, Universiti Malaysia Terengganu, Malaysia
Copyright © 2012 Adkins, Pugh, McKenna and Nielsen. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: David R. Nielsen, Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ 85287-6106, USA. e-mail: firstname.lastname@example.org