Metabolic engineering of Pseudomonas putida for production of vanillylamine from lignin-derived substrates

Title	Metabolic engineering of Pseudomonas putida for production of vanillylamine from lignin-derived substrates
Authors	João Heitor Colombelli Manfrão-Netto, Fredrik Lund, Nina Muratovska, Elin M. Larsson, Nádia Skorupa Parachin and Magnus Carlquist
Source	Microbial Biotechnology, 14( 6), 2448– 2462, 2021
Abstract	Whole-cell bioconversion of technical lignins using Pseudomonas putida strains overexpressing amine transaminases (ATAs) has the potential to become an eco-efficient route to produce phenolic amines. Here, a novel cell growth-based screening method to evaluate the in vivo activity of recombinant ATAs towards vanillylamine in P. putida KT2440 was developed. It allowed the identification of the native enzyme Pp-SpuC-II and ATA from Chromobacterium violaceum (Cv-ATA) as highly active towards vanillylamine in vivo. Overexpression of Pp-SpuC-II and Cv-ATA in the strain GN442ΔPP_2426, previously engineered for reduced vanillin assimilation, resulted in 94- and 92-fold increased specific transaminase activity, respectively. Whole-cell bioconversion of vanillin yielded 0.70 ± 0.20 mM and 0.92 ± 0.30 mM vanillylamine, for Pp-SpuC-II and Cv-ATA, respectively. Still, amine production was limited by a substantial re-assimilation of the product and formation of the by-products vanillic acid and vanillyl alcohol. Concomitant overexpression of Cv-ATA and alanine dehydrogenase from Bacillus subtilis increased the production of vanillylamine with ammonium as the only nitrogen source and a reduction in the amount of amine product re-assimilation. Identification and deletion of additional native genes encoding oxidoreductases acting on vanillin are crucial engineering targets for further improvement.
Type	Journal paper
URL	https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/1751-7915.13764
DOI	10.1111/1751-7915.13764
Tag	Col+21-microbio
ID	2021x_
Funding	RSI Soil Syn Bio
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