Microbial degradation characteristics and kinetics of novel pyrimidynyloxybenzoic herbicide ZJ0273 by a newly isolated Bacillus sp. CY.

ZJ0273 (propyl 4-(2-(4,6-demethoxy pyrimidin-2-yloxy)benzylamino)benzoate) is a novel herbicide developed in China for oilseed crop. Sixteen bacteria capable of utilizing ZJ0273 as the sole carbon source were isolated from soils. One of the isolates was designated as Bacillus sp. CY based on its physiological and biochemical characteristics and phylogenetic analysis of 16S rDNA sequences. The present study aimed to investigate the ZJ0273 degradation characteristics and kinetics by Bacillus sp. CY which has the ability to utilize ZJ0273 as the sole source of carbon and energy under aerobic conditions. The optimum biodegradation temperature, pH, and ZJ0273 initial concentration were 20-40 °C, 5.0-9.0, and 50-400 mg/l, respectively. Strain CY degraded 65 % of ZJ0273 (initial concentration of 50 mg/l) during 30 days of incubation in basal mineral medium at pH 8.0 and 35 °C. DT50 (half-life value), k (degradation rate constant of ZJ0273), and R (2) are 19.20 days, 0.0361 day(-1), and 0.9464, respectively.