Isolation and Characterization of an Aniline-degrading and Phenol-degrading Bacterium*

Abstract

A bacterial strain ANP capable of efficiently degrading aniline and phenol was isolated from activated sludge of a sewage treatment plant.The strain can be cultivated by using aniline and phenol as its sole carbon and energy sources.It is identified as Delftia sp.according to its morphology,biochemical properties and 16S rDNA sequence analysis.Further study indicated that the optimal pH and temperature for cell growth and aniline degradation were 6 and 30 ℃,respectively;the optimal concentration of aniline was 2 000 mg L-1;the optimal pH and temperature for cell growth and phenol degradation were 8 and 35 ℃,respectively;and the optimal concentration of phenol was 1 500 mg L-1.When cultivated with both phenol and aniline,strain ANP could only degrade aniline at first,but the both could be degraded thoroughly after 42 h.Enzymatic analysis showed that aniline was degraded in meta cleavage pathway,while phenol in ortho cleavage pathway.Fig 4,Tab 1,Ref 18