Abstract:

One strain that can grow with atrazine as sole nitrogen source, W4 was isolated and screened from sludge of workshop in the pesticide factory under 10℃.This strain was identified as Pseudomonas through 16S rDNA basic sequence detection and comparison. The optimum degradation conditions were optimized as following: the initial pH is 7-9, and the carbon source is sucrose and lactose. Under the optimum conditions, degradation kinetics of atrazine follows zero-order kinetics equation at the initial concentration of 34 mg/L,22 mg/L and 10 mg/L, and degradation kinetics of atrazine follows firstorder kinetics equation at the initial concentration of 5 mg/L. GC/MS analysis shows that atrazine can be hydrolyzed and dehalogenated by strain W4; the biodegradation product- hydroxyatrazine is confirmed.

Key words: atrazine, low temperature, screening, degradation mechanism, 16S rDNA sequencing