Studies On Isolation And Characterazation Of A P-Chloroaniline-Degrading Bacterial Strain

A bacterial strain that degrades p-chloroaniline(PCA) was isolated from activated sludge of wastewater treatment plant treating wastewater from a chemical factory. Results indicated this strain took p-chloroaniline as sole carbon, energy sources and nitrogen, simultaneitily, including aniline, o-amidophenol and m-amidophenol. It was identified as Diaphorobacter sp. PCA039 according to its morphology, and biochemical properties, and 16S rDNA sequence analysis.Further study indicated that chloride ion was released simultaneously and stoichemically to p-chloroaniline degradation during cultivation. The optimal pH and temperature for cell growth and p-chloroaniline degradation were 7.5 and 30C, respectively, and the optimal concentration of p-chloroaniline in three days was 300 mg/L (2.35 mmol/L) and air amount in 500 ml system is 150 ml. Enzymatic analysis showed that initial reactions of p-chloroaniline degradation by Diaphorobacter sp. PCA039 were catalysed by aniline dioxygenase and then the cleavage of aromatic ring catalysed by chlorocatechol 2,3-dioxygenase(C23O). C23O could transform several catechols, and its enzymatic activity is higher.By this time, Diaphorobacter sp. PCA039 was the first bacterial strain took p-chloroaniline as sole carbon, energy sources and nitrogen in China. It was priliminarily explained for the characteristics and mechanism the degradation of p-chloroaniline from the research of strain PCA039, and the bacteril strain PCA039 with high capability to degrade PCA was provided in application practice. In a word, this study was expected to be bestead for treating with the pollution of chloroanilines (CAs) of China.