Continuous degradation of 3-chloroaniline by calcium-alginate-entrapped cells of Pseudomonas acidovorans CA28: influence of additional substrates

Abstract

Cells of Pseudomonas acidovorans strain CA28 capable of degrading aniline, 3-chloroaniline (3-CA), and 4-chloroaniline (4-CA) were immobilized in 1.5% (w/v) calcium alginate and cultivated in a special air-lift fermentor. For 6 weeks the fermentor was run as a chemostat with 3-CA (850 to 1166 μmol·l−1) as the sole source of carbon, nitrogen, and energy at dilution rates up to 0.297 h−1, which resulted in complete mineralization of the chloroaniline. Effects of aniline, monochloroanilines, 2,6-dichloroaniline, 3,4-dichloroaniline, fructose and acetate on the continuous degradation of 3-CA were estimated by single addition of these substrates to the fermentor. Fructose and acetate were metabolized without affecting 3-CA degradation, whereas addition of aniline derivatives resulted in a reversible decrease of the 3-CA degradation rate and thus intermediate accumulation of 3-CA in the fermentor.