Weaving a Fermented Path to Nylons

Microbial enzymes create precursors of nylon while avoiding harsh chemicals and energy-demanding heat.

Image courtesy of JBEI

Scientists discovered an enzyme, in a bacteria (artistically represented on the right), that takes linear molecules (starting at the left arrow) and turns them into the precursors (right) needed for nylon manufacturing. The biological process works at room temperature without harsh chemicals.

The Science

Known for their extreme toughness, strength, and elasticity, nylon is used for flooring, car parts, food packaging, and much more. Making nylon involves chemicals called lactams. Ring-structured lactams are precursors in the manufacture of nylons. Precursors participate in a chemical reaction producing another compound. However, biological production of these highly valued chemicals has been limited due to a lack of enzymes that form lactam rings. Scientists discovered and tested an enzyme in the bacteria Streptomyces aizunensis that fulfills a crucial step in biological synthesis of these precursors.  

The Impact

Current commercial nylon production methods start with crude oil and require energy-intense processes and harsh acidic reactions. This is the first study to demonstrate a suitable enzyme for synthesis of lactams under microbial fermentation conditions for the manufacture of nylon. In a proof-of-concept study, a Streptomyces enzyme forms five-, six-, and even seven-membered rings at mild temperatures. The result? Lactams produced via fermentation. Petroleum, harsh chemicals, and heat are avoided.

Summary

Millions of tons of nylon is produced annually requiring harsh conditions. Manufacturing nylon involves making five- and six-member ring compound precursors, called lactams. Biological production of these highly valued precursors will reduce the need for petroleum and avoid toxic harsh conditions. However, biological production has been limited due to a lack of enzymes that carry out crucial steps at room temperature and pressure. The U.S. Department of Energy Joint BioEnergy Institute researchers demonstrated production of the lactam precursors using an enzyme—acyl-CoA ligase—from Streptomyces aizunensis. The enzyme has a broad substrate spectrum and can turn linear amino acids into their corresponding cyclic lactams when the reaction occurs in Escherichia coli. Further metabolic engineering of the pathway leads to production of the lactams directly from the common amino acid lysine. The research offers insights into manufacturing nylon, a vital material, without energy-intensive heat and harsh chemicals.

Contact

PM Contact
N. Kent Peters
Program Manager, Office of Biological and Environmental Research
[email protected], 301-903-5549

PI Contact
Jay Keasling
CEO, Joint BioEnergy Institute, Emeryville, California 94608
[email protected]  

Funding

This work was funded by the Joint BioEnergy Institute, which is supported by the U.S. Department of Energy (DOE), Office of Science, Office of Biological and Environmental Research, through contract DE-AC02-05CH11231 between Lawrence Berkeley National Laboratory, DOE and The Synthetic Biology Engineering Research Center through National Science Foundation grant NSF EEC 0540879.

Publications

J. Zhang, J.F. Barajas, M. Burdu, G. Wang, E.E. Baidoo, and J.D. Keasling, “Application of an acyl-CoA ligase from Streptomyces aizunensis for lactam biosynthesis.” ACS Synthetic Biology 6(5), 884-890 (2017). [DOI: 10.1021/acssynbio.6b00372]

Related Links

Joint BioEnergy Institute Website

Highlight Categories

Program: BER , BSSD , BRCs

Performer: University , DOE Laboratory

Additional: Collaborations , Non-DOE Interagency Collaboration