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The screening of 16,000 synthetic compounds for induction and inhibition and inhibition of quorum sensing in a Pseudomonas putida N-acylated L-homoserine lactone (AHL) sensor strain engineered with the LasR transcriptional activator is reported. High-throughput screening identified several compound with ability to inhibit and induce LasR activity which is important for controlling virulence gene expression in the opportunistic pathogen Pseudomonas aeruginosa and could be applied as therapeutic target.

The molecular analysis of two bacterioferritin genes, bfr[alpha] and bfr[beta] isolated from the model rhizobacterium Pseudomonas putida KT2440 was conducted to gain insight into the regulatory systems controlling the expression of these genes and the roles of these proteins in iron homeostasis. The data provide insight into the interaction-dependent function of bfr[alpha] and bfr[beta] and the primary benefit of the bacterioferritins to P. putida KT2440 for the enhancement of its survival in the environment by strengthening its tolerance to iron starvation.

A novel tightly regulated gene expression system is developed for Escherichia coli by applying the regulatory elements of the Pseudomonas putida F1 cym and cmt operons to control target gene expression at the transcriptional level by using p-isopropylbenzoate (cumate) as an inducer. Several Escherichia coli strains utilized in production and expression studies have shown high expression yields of target protein, tight regulation, rheostatic control and a homogeneous high-expression bacterial culture.

The phenomenon and application of using extracytosolic enzymes and medium conditions like pH are described that can catalyze metabolic pathways beyond their intracellular and extracytosolic catalysis. The method is termed as integrated bioprocessing as it has integrated intracellular and extracytosolic catalysis and it is applied to a lactonization reaction in Pseudomonas putida for the economical and high-titer biosynthesis of 4-valerolactone from the renewable source levulinic acid.

The amplification, cloning, functional expression and characterization of a 4-hydroxyacetophenone (HAPMO) from Pseudomonas putida JD1 oxidizing a broad range of aromatic ketones and further substrates are described. The studies have shown that the enzyme has oxidized ketones such as 3-phenyl-2-butanone with excellent enantioselectivity.

A newly developed dual luciferase reporter (DLR) system is applied to strain KT2440 of Pseudomonas putida to assay its intracellular iron status and three putative bacterioferritin gene (Bfr, bfr[alpha], bfr[beta]) expressions. The results obtained from sensitive and reproducible DLR revealed that the expression of bfr (PP4856) is inversely related to the iron concentration and hence is more likely to encode a Dps-like protein rather than a bacterioferritin.

The solvent-tolerant bacterium Pseudomonas putida S12 was engineered to use xylose as a substrate by expressing xylose isomerase (XylA) and xylulokinase (XylB) from Escherichia coli. The findings from the Pseudomonas putida S12 strain that is capable of utilizing glucose, xylose, and arabinose could be applied as an optimized host strain for efficient, green production of chemicals from renewable lignocellulose-derived feedstock.