Engineering Pseudomonas fluorescens for biodegradation of 2,4-dinitrotoluene

MONTI M.R.; SMANIA A.M.,; FABRO G.; ALVAREZ M.E; ARGARAÑA C.E.

AMER SOC MICROBIOLOGY

Año: 2005 vol. 71 p. 8864 - 8864

sing the genes encoding the 2,4-dinitrotoluene degradation pathway enzymes, the nonpathogenic psychrotolerant rhizobacterium Pseudomonas fluorescens ATCC 17400 was genetically modified for degradation ofthis priority pollutant. First, a recombinant strain designated MP was constructed by conjugative transfer from Burkholderia sp. strain DNT of the pJS1 megaplasmid, which contains the dnt genes for 2,4-dinitrotoluene degradation. This strain was able to grow on 2,4-dinitrotoluene as the sole source of carbon, nitrogen, andenergy at levels equivalent to those of Burkholderia sp. strain DNT. Nevertheless, loss of the 2,4-dinitrotoluenedegradative phenotype was observed for strains carrying pJS1. The introduction of dnt genes into the P. fluorescens ATCC 17400 chromosome, using a suicide chromosomal integration Tn5-based delivery plasmidsystem, generated a degrading strain that was stable for a long time, which was designated RE. This strain wasable to use 2,4-dinitrotoluene as a sole nit