Effect of mutation of chemotaxis signal transduction gene cheA in Pseudomonas putida DLL-1 on its chemotaxis and methyl parathion biodegradation

Abstract:

Pseudomonas putida DLL-1 is a high effective methyl parathion(MP) degrading strain, which is also of chemotaxis to MP. cheA, responsible for coding histidine kinase, plays an important role in bacterial chemotaxis signal transduction. In order to study the effect of bacterial chemotaxis on in-situ biodegradation of pesticides, cheA in chromosome of P. putida DLL-1 was mutated by gene-targeting and successfully obtained a MP-chemotaxis mutant DAK. The mutant DAK shows the same growth ability as wild-type DLL-1 in LB medium. The degrading rate of 50 mg/kg MP in non-sterile and sterile soil of chemotaxis mutant DAK is about 20%～30% lower than that of wild-type bacterial DLL-1. Lose of chemotaxis in DLL-1 would decline its degradation ability of MP. It was demonstrated that chemotaxis plays an important role in the in-situ biodegradation of pesticides.

Key words:Chemotaxis; Pesticide biodegradation; Pseudomonas putida DLL-1; cheA: Methyl parathionv