Comparison of Three Xylose Pathways in Pseudomonas putida KT2440 for the Synthesis of Valuable Products

Abstract

Pseudomonas putida KT2440 is a well-established chassis in industrial biotechnology. To increase the substrate spectrum, we implemented three alternative xylose utilization pathways, namely the Isomerase, Weimberg, and Dahms pathways. The synthetic operons contain genes from Escherichia coli and Pseudomonas taiwanensis. For isolating the Dahms pathway in P. putida KT2440 two genes (PP_2836 and PP_4283), encoding an endogenous enzyme of the Weimberg pathway and a regulator for glycolaldehyde degradation, were deleted. Before and after adaptive laboratory evolution, these strains were characterized in terms of growth and synthesis of mono-rhamnolipids and pyocyanin. The engineered strain using the Weimberg pathway reached the highest maximal growth rate of 0.30 h −1. After adaptive laboratory evolution the lag phase was reduced significantly. The highest titers of 720 mg L −1 mono-rhamnolipids and 30 mg L −1 pyocyanin were reached by the evolved strain using the Weimberg or an engineered strain using the Isomerase pathway, respectively. The different stoichiometries of the three xylose utilization pathways may allow engineering of tailored chassis for valuable bioproduct synthesis.

Bio-upcycling of polyethylene terephthalate

“…FBA has been carried out as described previously 73 . Briefly, the genome-scale model of P. putida KT2440, iJN1411, was used 74 and extended by the biosynthesis routes for HAA production and the metabolization routes for EG and TA.…”

Killing Two Birds With One Stone – Strain Engineering Facilitates the Development of a Unique Rhamnolipid Production Process

“…Sample preparation and analysis via high performance liquid chromatography (HPLC) for the measurement of ethanol and extracellular metabolites, e.g., acetate, was performed with the same method for glucose and other organic acids as described in Bator et al (2020) . It was used a Metab-AAC 300 × 7.8 mm separation column (particle size: 10 μm, ISERA GmbH, Düren, Germany).…”

“…The plasmid pSK02 harboring the rhlAB genes from P. aeruginosa PA01 was integrated into the genome of P. putida KT2440 E1.1 via transposition. Identification and selection of biosurfactant producing clones was performed as described by Bator et al (2020), using ethanol as substrate instead of glucose.…”

“…The overall goal is to establish a circular bioeconomy in which also lignocellulosic biomass and side- and waste streams are used as energy and carbon source. Several studies deal with the production of rhamnolipids from alternative resources, e.g., butane, agro-industrial waste, glycerol, organic acids derived from bio-oil, and xylose ( Gehring et al, 2016 ; Gudiña et al, 2016 ; Tiso et al, 2017 ; Arnold et al, 2019 ; Bator et al, 2020 ). In the 1990s, ethanol was already considered as an alternative carbon source for rhamnolipid production ( Matsufuji et al, 1997 ).…”

A Combined Bio-Chemical Synthesis Route for 1-Octene Sheds Light on Rhamnolipid Structure

“…While in this study, glucose has been used for the synthesis of the intermediate molecules, recent studies show that the usage of components of lignocellulosic biomass is an option (e.g., xylose [63]). This would increase the sustainability of the here proposed approach.…”