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Engineering Aspergillus Niger for Galactaric Acid Production: Elimination of Galactaric Acid Catabolism by Using RNA Sequencing and CRISPR/Cas9

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Publisher Biomed Central
Date 2016 Dec 14
PMID 27955649
Citations 52
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Abstract

Background: meso-Galactaric acid is a dicarboxylic acid that can be produced by the oxidation of D-galacturonic acid, the main constituent of pectin. Mould strains can be engineered to perform this oxidation by expressing the bacterial enzyme uronate dehydrogenase. In addition, the endogenous pathway for D-galacturonic acid catabolism has to be inactivated. The filamentous fungus Aspergillus niger would be a suitable strain for galactaric acid production since it is efficient in pectin hydrolysis, however, it is catabolizing the resulting galactaric acid via an unknown catabolic pathway.

Results: In this study, a transcriptomics approach was used to identify genes involved in galactaric acid catabolism. Several genes were deleted using CRISPR/Cas9 together with in vitro synthesized sgRNA. As a result, galactaric acid catabolism was disrupted. An engineered A. niger strain combining the disrupted galactaric and D-galacturonic acid catabolism with an expression of a heterologous uronate dehydrogenase produced galactaric acid from D-galacturonic acid. The resulting strain was also converting pectin-rich biomass to galactaric acid in a consolidated bioprocess.

Conclusions: In the present study, we demonstrated the use of CRISPR/Cas9 mediated gene deletion technology in A. niger in an metabolic engineering application. As a result, a strain for the efficient production of galactaric acid from D-galacturonic acid was generated. The present study highlights the usefulness of CRISPR/Cas9 technology in the metabolic engineering of filamentous fungi.

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References
1.
Martens-Uzunova E, Schaap P . An evolutionary conserved d-galacturonic acid metabolic pathway operates across filamentous fungi capable of pectin degradation. Fungal Genet Biol. 2008; 45(11):1449-57. DOI: 10.1016/j.fgb.2008.08.002. View

2.
Zhang C, Meng X, Wei X, Lu L . Highly efficient CRISPR mutagenesis by microhomology-mediated end joining in Aspergillus fumigatus. Fungal Genet Biol. 2015; 86:47-57. DOI: 10.1016/j.fgb.2015.12.007. View

3.
Chang Y, Feingold D . D-glucaric acid and galactaric acid catabolism by Agrobacterium tumefaciens. J Bacteriol. 1970; 102(1):85-96. PMC: 284973. DOI: 10.1128/jb.102.1.85-96.1970. View

4.
Kuivanen J, Dantas H, Mojzita D, Mallmann E, Biz A, Krieger N . Conversion of orange peel to L-galactonic acid in a consolidated process using engineered strains of Aspergillus niger. AMB Express. 2014; 4:33. PMC: 4052776. DOI: 10.1186/s13568-014-0033-z. View

5.
Benz J, Protzko R, Andrich J, Bauer S, Dueber J, Somerville C . Identification and characterization of a galacturonic acid transporter from Neurospora crassa and its application for Saccharomyces cerevisiae fermentation processes. Biotechnol Biofuels. 2014; 7(1):20. PMC: 3933009. DOI: 10.1186/1754-6834-7-20. View