Analysis of solvent tolerance in Pseudomonas putida DOT‐T1E based on its genome sequence and a collection of mutants

Abstract

Pseudomonas putida strains are prevalent in a variety of pristine and polluted environments. The genome of the solvent‐tolerant P. putida strain DOT‐T1E which thrives in the presence of high concentrations of monoaromatic hydrocarbons, contains a circular 6.3 Mbp chromosome and a 133 kbp plasmid. Omics information has been used to identify the genes and proteins involved in solvent tolerance in this bacterium. This strain uses a multifactorial response that involves fine‐tuning of lipid fluidity, activation of a general stress‐response system, enhanced energy generation, and induction of specific efflux pumps that extrude solvents to the medium. Local and global transcriptional regulators participate in a complex network of metabolic functions, acting as the decision makers in the response to solvents.

GtrS and GltR form a two-component system: the central role of 2-ketogluconate in the expression of exotoxin A and glucose catabolic enzymes inPseudomonas aeruginosa

“…As the number of characterized TCSs grows, the inventory of variations on the basic scheme also grows (34,35). In this study, we have shown that the GrtS/GltR regulators form a previously unidentified TCS.…”

Control of metabolite efflux in microbial cell factories: current advances and future prospects

“…Any of these are candidates for manipulation to cause the efflux of biotechnological products. Known ones include those for dipeptides [340], antibiotics [132,133,135,136], and solvents [133,341,342]. Broadly similar statements are true in S. cerevisiae, where a variety of efflux pumps help remove intracellular toxicants of all kinds [343][344][345][346][347][348].…”

Tolerance engineering in bacteria for the production of advanced biofuels and chemicals

“…This topic has been explored from the viewpoint of bioremediation of hydrocarbon spills and contamination, biocatalysis using whole microbes in two-phase solvent systems, and the production of solvent-like compounds. Several recent and thoughtful reviews [3,4,9,[13][14][15][16] and comprehensive systems biology studies [17][18][19][20][21][22][23][24][25][26][27] focus on evaluating solvent tolerance across numerous bacterial hosts (also see Box 1). Although a given solvent will elicit specific stress responses, some generalizable trends are now established.…”

“…Solvent-tolerant microbes and choice of microbial host strains Pseudomonads are some of most solvent-tolerant microbes. With extensive and redundant capacities for short-term (cis-to-trans [28]) and long-term (increase in saturation [32]) phospholipid fatty acid (PLFA) modifications and potent efflux systems (TtgABC, TtgDEF, and TtgGHI in Pseudomonas putida DOT-T1E [26,67] and SrpABC in P. putida S12 [15]), these microbes have superior tolerance to BTEX (benzene, toluene, ethylbenzene, xylene) chemicals as well as other hydrocarbons (e.g., n-hexane, cyclohexane). In general their native resilience toward compounds with log P < 4 (Box 1) is higher than industrial hosts such as Escherichia coli.…”