%0 Journal Article
%A Li, Wing-Jin
%A Narancic, Tanja
%A Kenny, Shane T.
%A Niehoff, Paul-Joachim
%A O’Connor, Kevin
%A Blank, Lars M.
%A Wierckx, Nick
%T Unraveling 1,4-Butanediol Metabolism in Pseudomonas putida KT2440
%J Frontiers in microbiology
%V 11
%@ 1664-302X
%C Lausanne
%I Frontiers Media
%M FZJ-2020-01505
%P 382
%D 2020
%Z Biotechnologie 1
%X Plastics, in all forms, are a ubiquitous cornerstone of modern civilization. Although humanity undoubtedly benefits from the versatility and durability of plastics, they also cause a tremendous burden for the environment. Bio-upcycling is a promising approach to reduce this burden, especially for polymers that are currently not amenable to mechanical recycling. Wildtype P. putida KT2440 is able to grow on 1,4-butanediol as sole carbon source, but only very slowly. Adaptive laboratory evolution (ALE) led to the isolation of several strains with significantly enhanced growth rate and yield. Genome re-sequencing and proteomic analysis were applied to characterize the genomic and metabolic basis of efficient 1,4-butanediol metabolism. Initially, 1,4-butanediol is oxidized to 4-hydroxybutyrate, in which the highly expressed dehydrogenase enzymes encoded within the PP_2674-2680 ped gene cluster play an essential role. The resulting 4-hydroxybutyrate can be metabolized through three possible pathways: (i) oxidation to succinate, (ii) CoA activation and subsequent oxidation to succinyl-CoA, and (iii) beta oxidation to glycolyl-CoA and acetyl-CoA. The evolved strains were both mutated in a transcriptional regulator (PP_2046) of an operon encoding both beta-oxidation related genes and an alcohol dehydrogenase. When either the regulator or the alcohol dehydrogenase is deleted, no 1,4-butanediol uptake or growth could be detected. Using a reverse engineering approach, PP_2046 was replaced by a synthetic promotor (14g) to overexpress the downstream operon (PP_2047-2051), thereby enhancing growth on 1,4-butanediol. This work provides a deeper understanding of microbial 1,4-butanediol metabolism in P. putida, which is also expandable to other aliphatic alpha-omega diols. It enables the more efficient metabolism of these diols, thereby enabling biotechnological valorization of plastic monomers in a bio-upcycling approach.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:32256468
%U <Go to ISI:>//WOS:000525716600001
%R 10.3389/fmicb.2020.00382
%U https://juser.fz-juelich.de/record/874551