Metabolic engineering of Escherichia coli for the production of cinnamaldehyde

Abstract

BackgroundPlant parasitic nematodes are harmful to agricultural crops and plants, and may cause severe yield losses. Cinnamaldehyde, a volatile, yellow liquid commonly used as a flavoring or food additive, is increasingly becoming a popular natural nematicide because of its high nematicidal activity and, there is a high demand for the development of a biological platform to produce cinnamaldehyde.ResultsWe engineered Escherichia coli as an eco-friendly biological platform for the production of cinnamaldehyde. In E. coli, cinnamaldehyde can be synthesized from intracellular l-phenylalanine, which requires the activities of three enzymes: phenylalanine-ammonia lyase (PAL), 4-coumarate:CoA ligase (4CL), and cinnamoyl-CoA reductase (CCR). For the efficient production of cinnamaldehyde in E. coli, we first examined the activities of enzymes from different sources and a gene expression system for the selected enzymes was constructed. Next, the metabolic pathway for l-phenylalanine biosynthesis was engineered to increase the intracellular pool of l-phenylalanine, which is a main precursor of cinnamaldehyde. Finally, we tried to produce cinnamaldehyde with the engineered E. coli. According to this result, cinnamaldehyde production as high as 75 mg/L could be achieved, which was about 35-fold higher compared with that in the parental E. coli W3110 harboring a plasmid for cinnamaldehyde biosynthesis. We also confirmed that cinnamaldehyde produced by our engineered E. coli had a nematicidal activity similar to the activity of commercial cinnamaldehyde by nematicidal assays against Bursaphelenchus xylophilus.ConclusionAs a potential natural pesticide, cinnamaldehyde was successfully produced in E. coli by construction of the biosynthesis pathway and, its production titer was also significantly increased by engineering the metabolic pathway of l-phenylalanine.Electronic supplementary materialThe online version of this article (doi:10.1186/s12934-016-0415-9) contains supplementary material, which is available to authorized users.

Screening of an Escherichia coli promoter library for a phenylalanine biosensor

“…As precursor for the artificial sweetener aspartame or as building block for pharmaceutical products including infusion fluids or HIV protease inhibitors, L-phenylalanine has played an important role for many years (Sprenger 2006;. Furthermore, the commercially interesting aromatic compounds pinosylvin (van Summeren-Wesenhagen and Marienhagen 2015), cinnamic and p-hydroxycinnamic acid (Sariaslani 2007;Vargas-Tah et al 2015), cinnamaldehyde, and phenylpyruvic acid (Bang et al 2016;Hou et al 2015) are synthesized from the precursor L-phenylalanine and serve as flavor enhancers, cosmetical, or pharmaceutical building blocks.…”

“…E. coli serves as an important platform organism producing L-phenylalanine-as most microorganisms-via the shikimate pathway (Bentley 1990;Sprenger 2007). Rational engineering approaches yielded strains producing final L-phenylalanine titers of up to 50 g/L from glucose (Backman et al 1990;Rüffer et al 2004) and 13.4 g/L based on glycerol as substrate (Weiner et al 2014).…”

Optoregulated Drug Release from an Engineered Living Hydrogel

“…Being the workhorse for genetic engineering, E. coli is the most extensively used bacterium for which the highest variety of genetic modules are available. E. coli has been engineered for metabolic production of drugs such as riboflavin, 29 artemisinin, 30 salidroside, 31 cinnamaldehyde, 32 carbapenem, 33 violacein, 34,35 deoxyviolacein (dVio), 34,35 etc. at industrial scales.…”

Optoregulated Drug Release from an Engineered Living Material: Self‐Replenishing Drug Depots for Long‐Term, Light‐Regulated Delivery

“…E. coli has been engineered for metabolic production of drugs such as artemisinin, cinnamaldehyde, carbapenem, violacein, deoxyviolacein (dVio), etc., at industrial scales . Among these, the l ‐tryptophan‐derived bisindoles dVio and violacein are attractive due to their antibacterial, antifungal, and antitumoral properties and the possibility to produce them at gram scales .…”

“…While the currently described system is unsuitable for application inside the body, it could be acceptable for skin‐based therapies and cosmetics that would also be able to utilize light‐responsive properties most effectively. Modifying the system to produce other drugs such as cinnamaldehyde and carbapenem that have shown to be optimally synthesized at 37 °C in E. coli and secreted without the requirement of solubilizers could be considered for in vivo clinical applications.…”