A platform pathway for production of 3-hydroxyacids provides a biosynthetic route to 3-hydroxy-γ-butyrolactone

The replacement of petroleum feedstocks with biomass to produce platform chemicals requires the development of appropriate conversion technologies. 3-Hydroxy-γ-butyrolactone has been identified as one such chemical; however, there are no naturally occurring biosynthetic pathways for this molecule or...

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Bibliographic Details
Main Authors: Martin, Collin H., Dhamankar, Himanshu Hemant, Tseng, Hsien-Chung, Sheppard, Micah James, Reisch, Christopher R., Prather, Kristala L. Jones
Other Authors: Massachusetts Institute of Technology. Department of Chemical Engineering
Format: Article
Language:en_US
Published: Nature Publishing Group 2013
Online Access:http://hdl.handle.net/1721.1/79823
https://orcid.org/0000-0003-0437-3157
https://orcid.org/0000-0002-4908-3914
Description
Summary:The replacement of petroleum feedstocks with biomass to produce platform chemicals requires the development of appropriate conversion technologies. 3-Hydroxy-γ-butyrolactone has been identified as one such chemical; however, there are no naturally occurring biosynthetic pathways for this molecule or its hydrolyzed form, 3,4-dihydroxybutyric acid. Here we design a novel pathway to produce various chiral 3-hydroxyacids, including 3,4-dihydroxybutyric acid, consisting of enzymes that condense two acyl-CoAs, stereospecifically reduce the resulting β-ketone and hydrolyze the CoA thioester to release the free acid. Acetyl-CoA serves as one substrate for the condensation reaction, whereas the second is produced intracellularly by a pathway enzyme that converts exogenously supplied organic acids. Feeding of butyrate, isobutyrate and glycolate results in the production of 3-hydroxyhexanoate, 3-hydroxy-4-methylvalerate and 3,4-dihydroxybutyric acid+3-hydroxy-γ-butyrolactone, respectively, molecules with potential uses in applications from materials to medicines. We also unexpectedly observe the condensation reaction resulting in the production of the 2,3-dihydroxybutyric acid isomer, a potential value-added monomer.