Comparative analysis of microbial community under acclimation of linear alkylbenzene sulfonate (LAS) surfactants and degradation mechanisms of functional strains.

Abstract

Linear alkylbenzene sulfonate (LAS) is one of the most widely used anionic surfactants and a common toxic pollutant in wastewater. This study employed high throughput sequencing to explore the microbial community structure within activated sludge exposed to a high concentration of LAS. Genera such as Pseudomonas, Aeromonas, Thauera and Klebsiella exhibited a significant positive correlation with LAS concentrations. Furthermore, Comamonas and Klebsiella were significantly enriched under the stress of LAS. Moreover, bacterial strains with LAS-degrading capability were isolated and characterized to elucidate the degradation pathways. The Klebsiella pneumoniae isolate L1 could effectively transform more than 60 % of 25 mg/L of LAS within 72 h. Chemical analyses revealed that L1 utilized the LAS sulfonyl group as a sulfur source to support its growth. Genomic and transcriptomic analyses suggested that strain L1 may uptake LAS through the sulfate ABC transport system and remove sulfonate with sulfate and sulfite reductases.