De novo biosynthesis and gram-level production of m-cresol in Aspergillus nidulans.
Appl Microbiol Biotechnol
; 105(16-17): 6333-6343, 2021 Aug.
Article
em En
| MEDLINE
| ID: mdl-34423409
ABSTRACT
The industrially important meta-cresol (m-cresol, 3-methylphenol) is mainly produced from fossil resources by chemical methods. The microbial production of m-cresol was rarely investigated. Herein, we constructed a platform for the overproduction of m-cresol in a modified fungus Aspergillus nidulans FGSC no. A1145∆ST∆EM, which gave a gram-level titer using starch as carbon resource. For the biosynthesis of m-cresol, the 6-methyl salicylic acid synthase (MSAS)-encoding gene patK and 6-methyl salicylic acid decarboxylase-encoding gene patG from A. clavatus were co-expressed in the host A. nidulans. Multiple strategies, including promotor engineering, gene multiplication, and fed-batch fermentation, were applied to raise the production of m-cresol, which resulted in the titers of 1.29 g/L in shaking flasks and 2.03 g/L in fed-batch culture. The chassis cell A. nidulans A1145∆ST∆EM was proved to possess better tolerance to m-cresol than yeast, as it could grow in the liquid medium containing up to 2.5 g/L of m-cresol. These results showed that A. nidulans has great potential to be further engineered for industrial production of m-cresol.Key points⢠m-Cresol was de novo biosynthesized by a fungal chassis cell Aspergillus nidulans.⢠Promoter engineering and gene multiplication implemented the fine-tuned genes expression.⢠The titer of m-cresol reached 2.03 g/L via fed-batch culture.
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Aspergillus nidulans
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En
Ano de publicação:
2021
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Article