Application of nitroarene dioxygenases in the design of novel strains that degrade chloronitrobenzenes.
Bottom Line: To address this need, we created engineered strains with a novel degradation pathway that reduces the total number of steps required to convert chloronitrobenzenes into compounds of central metabolism.We examined the ability of 2-nitrotoluene 2,3-dioxygenase from Acidovorax sp. strain JS42, nitrobenzene 1,2-dioxygenase (NBDO) from Comamonas sp. strain JS765, as well as active-site mutants of NBDO to generate chlorocatechols from chloronitrobenzenes, and identified the most efficient enzymes.Introduction of the wild-type NBDO and the F293Q variant into Ralstonia sp. strain JS705, a strain carrying the modified ortho pathway for chlorocatechol metabolism, resulted in bacterial strains that were able to sustainably grow on all three chloronitrobenzene isomers without addition of co-substrates or co-inducers.
Affiliation: Department of Microbiology, College of Biological Sciences, University of California, Davis, CA 95616, USA.Show MeSH
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Mentions: Possible reactions catalysed by nitroarene dioxygenases with CNBs. Solid black and white arrows indicate reactions detected by some or all of the nitroarene dioxygenases tested in this study. All of the reactions shown require NADH as a cofactor. Black arrows indicate reactions whose products are substrates for further metabolism by the modified ortho‐ring cleavage pathway (shown in Fig. 5). No evidence for the reactions indicated by dotted lines was obtained. 3ClCAT, 3‐chlorocatechol; 4ClCAT, 4‐chlorocatechol; 3NCAT, 3‐nitrocatechol; 4NCAT, 4‐nitrocatechol.
Affiliation: Department of Microbiology, College of Biological Sciences, University of California, Davis, CA 95616, USA.