Comparative transcriptomics and proteomics of p-hydroxybenzoate producing Pseudomonas putida S12: Novel responses and implications for strain improvement

Abstract

A transcriptomics and proteomics approach was employed to study the expression changes associated with p-hydroxybenzoate production by the engineered Pseudomonas putida strain S12palB1. To establish p-hydroxyben-zoate production, phenylalanine-tyrosine ammonia lyase (pal/tal) was introduced to connect the tyrosine biosynthetic and p-coumarate degradation pathways. In agreement with the efficient p-hydroxybenzoate production, the tyrosine biosynthetic and p-coumarate catabolic pathways were upregulated. Also many transporters were differentially expressed, one of which - a previously uncharacterized multidrug efflux transporter with locus tags PP1271-PP1273 - was found to be associated with p-hydroxyben-zoate export. In addition to tyrosine biosynthesis, also tyrosine degradative pathways were upregulated. Eliminating the most prominent of these resulted in a 22% p-hydroxy-benzoate yield improvement. Remarkably, the upregulation of genes contributing to p-hydroxybenzoate formation was much higher in glucose than in glycerol-cultured cells. © The Author(s) 2010.