title: Styrene biosynthesis from glucose by engineered E. coli.
abstract: Styrene is a large volume, commodity petrochemical with diverse commercial applications, including as a monomer building-block for the synthesis of many useful polymers. Here we demonstrate how, through the de novo design and development of a novel metabolic pathway, styrene can alternatively be synthesized from renewable substrates such as glucose. The conversion of endogenously synthesized l-phenylalanine to styrene was achieved by the co-expression of phenylalanine ammonia lyase and trans-cinnamate decarboxylase. Candidate isoenzymes for each step were screened from bacterial, yeast, and plant genetic sources. Finally, over-expression of PAL2 from Arabidopsis thaliana and FDC1 from Saccharomyces cerevisiae (originally classified as ferulate decarboxylase) in an l-phenylalanine over-producing Escherichia coli host led to the accumulation of up to 260 mg/L in shake flask cultures. Achievable titers already approach the styrene toxicity threshold (determined as ~300 mg/L). To the best of our knowledge, this is the first report of microbial styrene production from sustainable feedstocks.
authors: Chemical Engineering, Arizona State University, 501 E. Tyler Mall, Tempe, AZ 85287-6106, USA.
authors: Rebekah
authors: R
authors: McKenna
authors: David R
authors: DR
authors: Nielsen
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000096:biosynthesis* / Q000235:genetics; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D002262:Carboxy-Lyases / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression; D005947:Glucose / Q000235:genetics / Q000378:metabolism; D030781:Organisms, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010649:Phenylalanine / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D020058:Styrene / Q000378:metabolism*
chemical_list: D020058:Styrene; D010649:Phenylalanine; D002262:Carboxy-Lyases; C087194:phenylacrylic acid decarboxylase; D019747:Aldose-Ketose Isomerases; C471229:PAI2 protein, Arabidopsis; D005947:Glucose