Response of Pseudomonas putida to Complex, Aromatic‐Rich Fractions from Biomass

Abstract

There is strong interest in the valorization of lignin to produce valuable products; however, its structural complexity has been a conversion bottleneck. Chemical pretreatment liberates lignin‐derived soluble fractions that may be upgraded by bioconversion. Cholinium ionic liquid pretreatment of sorghum produced soluble, aromatic‐rich fractions that were converted by Pseudomonas putida (P. putida), a promising host for aromatic bioconversion. Growth studies and mutational analysis demonstrated that P. putida growth on these fractions was dependent on aromatic monomers but unknown factors also contributed. Proteomic and metabolomic analyses indicated that these unknown factors were amino acids and residual ionic liquid; the oligomeric aromatic fraction derived from lignin was not converted. A cholinium catabolic pathway was identified, and the deletion of the pathway stopped the ability of P. putida to grow on cholinium ionic liquid. This work demonstrates that aromatic‐rich fractions obtained through pretreatment contain multiple substrates; conversion strategies should account for this complexity.

Fatty Acid and Alcohol Metabolism in Pseudomonas putida: Functional Analysis Using Random Barcode Transposon Sequencing

“…Pseudomonas putida KT2440 is an important metabolic engineering chassis, which can readily metabolize compounds derived from lignocellulosic and plastic derived feedstocks (1)(2)(3), and has an ever-growing repertoire of advanced tools for genome modification (4)(5)(6)(7). Its upper glycolytic pathway architecture enables P. putida to natively generate large amounts of reducing equivalent (8), and it more robustly withstands metabolic burdens than many other frequently used host organisms (9).…”

“…Amongst the most important metabolisms not yet rigorously interrogated via omics-level analyses are fatty acid and alcohol degradation. Recently, fatty acids have been shown to be a non-trivial component of some feedstock streams (1) and, depending on their chain length, serve as high-value target molecules (21). Furthermore, intermediates in beta-oxidation can be channeled towards mega-synthases to produce more complex molecules (22), or used in reverse beta-oxidation to produce compounds such as medium chain n-alcohols (23).…”

Exploring the Lignin Catabolism Potential of Soil-Derived Lignocellulolytic Microbial Consortia by a Gene-Centric Metagenomic Approach

“…These microbial consortia were cultivated on untreated and heat-treated wheat straw [22], where lignin proportion is higher, but probably with lower recalcitrance compared to substrates used on the selection of WS1-M, SG-M and CS-M. In a recent proteomic-based study, Park et al [47] demonstrated that P. putida KT2440 significant induces the production of pca-derived proteins after growth on plant-derived lignolysate.…”

Generation of ionic liquid tolerant Pseudomonas putida KT2440 strains via adaptive laboratory evolution

“…1 In this regard, during recent decades, microbial conversion of the lignocellulosic-sugars has been studied extensively using various types of microbial hosts for its efficient utilization. Pseudomonas putida KT2440 (KT2440) has garnered attention due to its high inherent tolerance and capability to utilize the aromatic compounds [2][3][4][5][6] which constitute 5-30% of total carbon in lignocellulosic biomass. 7 One of the major difficulties in the bioprocessing of lignocellulosic biomass is due to its recalcitrance and irregular bond structure which limits the overall activity of depolymerizing enzymes.…”