Enrichment and isolation of linear alkylbenzenesulphonate (LAS) degrading bacteria from estuarine and coastal waters

Abstract

Linear alkylbenzene sulphonate (LAS) degrading bacteria were enriched and isolated from two autochthonous mixed bacterial cultures which were derived from estuarine and coastal waters of the Adriatic Sea. The enrichment was carried out in continuous-flow units using a commercial mixture of LAS as the limiting carbon- and energy-source. The adapted bacterial cultures were able to carry out primary biodegradation of LAS with high efficiency in the concentration range from 2 to 20 mg l −1. During the adaptation period, it was established that the composition of the mixed bacterial culture rather than the total number of bacteria determined the biodegradation efficiency. Based on their macromorphological characteristics, seven distinct bacterial strains were isolated and examined for LAS biodegradation using a shake culture method. It was shown that only one of the isolated strains degraded LAS as efficiently as the mixed bacterial cultures, whereas the efficiency of the other strains was significantly lower. The results suggested that the bacterial strain which biodegraded LAS efficiently might have been of terrestrial origin.