Bioremediation, Rhizoremediation, and Molecular Biology of Pseudomonas of Interest in Plant Protection

This sub-line focuses on the mechanisms underlying the key roles bacteria play in environmental recovery and plant health, and their biotechnological exploitation. Research in biodegradation has been oriented towards the elimination of toluene, TNT and lindane. Pseudomonas was the microorganism of choice for most studies of this sub-line what has allowed gathering in-depth knowledge on the physiology and molecular biology of this model bacterium. The mutant collection assembled by the Pseudomonas Reference Culture Collection (PRCC) has been a valuable tool for the development of this research line. The research activitivies of the PRCC are directed to the construction of a collection of mutants in all ORFs of the P. putida KT2440. The work on the XylR/XylS and TodS/TodT regulators of two different toluene degradation pathways and TtgR and TtgV regulators of solvent efflux pump genes has been part of the aims of this sub-line in the biodegradation and transcriptional regulation fields. Biodegradation studies have been expanded to the removal of other contaminants such as PAHs and chloroaromatics by soil bacteria in aerobiosis and anaerobiosis. From the point of view of plant protection, the study of Pseudomonas is particularly attractive. Thus, P. fluorescens and P. putida colonize the root surface and surrounding soil area (rhizosphere), promoting plant growth, mobilizing nutrients or protecting plants from harmful organisms through the induction of systemic resistance, or by direct mechanisms affecting survival of the pathogen. The molecular mechanisms involved in bacterial establishment and survival on plant surfaces and the role of signaling processes remain to be fully explored. Research is aimed at gaining insight into the bacterial genes, proteins and metabolites that play a role in competitive fitness, colonization, infection and defence.

Keywords

Pseudomonas, pollutants, biodegradation, solvent tolerance, catabolic pathways, gene regulation, catabolic engineering, microbial diversity, biofilm, rhizosphere, phytosphere, colonization, fitness,