SELECTION AND PRELIMINARY CHARACTERIZATION OF A PSEUDOMONAS-AERUGINOSA STRAIN MINERALIZING SELECTED ISOMERS IN A BRANCHED-CHAIN DODECYLBENZENESULPHONATE MIXTURE

A bacterium able to grow at the expense of some isomers in a commercia l surfactant preparation consisting of branched-chain dodecylbenzenesu lphonate was isolated (W51), and it was identified as a Pseudomonas ae ruginosa strain. A faster growing derivative was selected (W51D) after enrichment in batch culture under microaerobic conditions, using the surfactant as the sole source of carbon and energy, Strain W51D is the first microorganism reported to degrade at least 70% of a branched-ch ain alkylbenzenesulphonate mixture and to be resistant to high concent rations of this surfactant. The ability to degrade the surfactant was shown to be transferred by conjugation to other P. aeruginosa strains and to an Escherichia coli strain.