[Aniline removal by aerobic granules and high-efficiency aniline-degrading bacteria]

Aerobic granules were successfully cultivated with aniline as the sole source of carbon and nitrogen. This system could effectively degrade aniline as high as 6 000 mg/L. Two aniline-degrading strains which were named as adx1 and adx3, were isolated and purified from the aerobic granular sludge. The degradation characteristics of these two bacteria were different. The strain adxl possessed a relatively higher degradation rate of aniline, while the strain adx3 could stand up to a higher concentration of aniline than the strain adx1. The degrading process of these two strains followed the Haldane kinetic model. The maximum aniline biodegradation rates of adx1 and adx3 were up to 0.924 g/(g x h) and 0.645 g/(g x h), respectively. The maximum specific growth rates were as high as 0.487 g/(g x h) and 0.440 g/(g x h), respectively. Identification by 16S rDNA gene sequence analysis showed that adx1 and adx3 were Pseudomonas sp. and Achromobacter sp., which was consistent with the identification by the bands 1 and 4 in the PCR-DGGE profile of the aerobic aniline-degrading granules. Therefore, it could be proposed that the strains adx1 and adx3 were one of the main functional microorganisms inhabited in the aerobic granules.