1. Identification of a specific exporter that enables high production of aconitic acid in Aspergillus pseudoterreus.
- Author
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Deng S, Kim J, Pomraning KR, Gao Y, Evans JE, Hofstad BA, Dai Z, Webb-Robertson BJ, Powell SM, Novikova IV, Munoz N, Kim YM, Swita M, Robles AL, Lemmon T, Duong RD, Nicora C, Burnum-Johnson KE, and Magnuson J
- Subjects
- Membrane Transport Proteins genetics, Metabolic Engineering, Succinates metabolism, Aconitic Acid metabolism, Aspergillus genetics, Aspergillus metabolism
- Abstract
Aconitic acid is an unsaturated tricarboxylic acid that is attractive for its potential use in manufacturing biodegradable and biocompatible polymers, plasticizers, and surfactants. Previously Aspergillus pseudoterreus was engineered as a platform to produce aconitic acid by deleting the cadA (cis-aconitic acid decarboxylase) gene in the itaconic acid biosynthetic pathway. In this study, the aconitic acid transporter gene (aexA) was identified using comparative global discovery proteomics analysis between the wild-type and cadA deletion strains. The protein AexA belongs to the Major Facilitator Superfamily (MFS). Deletion of aexA almost abolished aconitic acid secretion, while its overexpression led to a significant increase in aconitic acid production. Transportation of aconitic acid across the plasma membrane is a key limiting step in its production. In vitro, proteoliposome transport assay further validated AexA's function and substrate specificity. This research provides new approaches to efficiently pinpoint and characterize exporters of fungal organic acids and accelerate metabolic engineering to improve secretion capability and lower the cost of bioproduction., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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