Biodegradation of aniline in an alkaline environment by a novel strain of the halophilic bacterium, Dietzia natronolimnaea JQ-AN

Dietzia natronolimnaea JQ-AN was isolated from industrial wastewater containing aniline. Under aerobic conditions, the JQ-AN strain degraded 87% of the aniline in a 300 mg L−1 aniline solution after 120 h of shake flask incubation in a medium containing sodium acetate. This strain had an unusually high salinity tolerance in minimal medium (0–6% NaCl, w/v). The optimal pH for microbial growth and aniline biodegradation was pH 8.0. Two liters of simulated aniline wastewater was created in a reactor at pH 8.0 and 3% NaCl (w/v), and biodegradation of aniline was tested over 7 days at 30 °C. For the initial concentrations of 100, 300, and 500 mg L−1, 100%, 80.5% and 72% of the aniline was degraded, respectively. Strain JQ-AN may use an ortho-cleavage pathway for dissimilation of the catechol intermediate.

► Dietzia natronolimnaea JQ-AN was isolated for aniline biodegradation. ► Highest degradation occurred at pH 8.0 and 3% NaCl (w/v). ► Sodium acetate had a stimulating effect on aniline degradation. ► Removal of aniline was 72–100% at 7 d HRT in a bioreactor, respectively. ► Aniline was degraded as an ortho-cleavage pathway of the catechol intermediate.