Sodium lauryl ether sulfate (SLES) degradation by nitrate-reducing bacteria

Ana M. S. Paulo (Corresponding author), Rozelin Aydin, Mauricio R. Dimitrov, Harm Vreeling, Ana J. Cavaleiro, Pedro A. García-Encina, Alfons J. M. Stams, Caroline M. Plugge

Research output: Contribution to journal/periodicalArticleScientificpeer-review

24 Citations (Scopus)
396 Downloads (Pure)


The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents and frequently ends up in wastewater treatment plants (WWTPs). While aerobic SLES degradation is well studied, little is known about the fate of this compound in anoxic environments, such as denitrification tanks of WWTPs, nor about the bacteria involved in the anoxic biodegradation. Here, we used SLES as sole carbon and energy source, at concentrations ranging from 50 to 1000 mg L−1, to enrich and isolate nitrate-reducing bacteria from activated sludge of a WWTP with the anaerobic-anoxic-oxic (A2/O) concept. In the 50 mg L−1 enrichment, Comamonas (50%), Pseudomonas (24%), and Alicycliphilus (12%) were present at higher relative abundance, while Pseudomonas (53%) became dominant in the 1000 mg L−1 enrichment. Aeromonas hydrophila strain S7, Pseudomonas stutzeri strain S8, and Pseudomonas nitroreducens strain S11 were isolated from the enriched cultures. Under denitrifying conditions, strains S8 and S11 degraded 500 mg L−1 SLES in less than 1 day, while strain S7 required more than 6 days. Strains S8 and S11 also showed a remarkable resistance to SLES, being able to grow and reduce nitrate with SLES concentrations up to 40 g L−1. Strain S11 turned out to be the best anoxic SLES degrader, degrading up to 41% of 500 mg L−1. The comparison between SLES anoxic and oxic degradation by strain S11 revealed differences in SLES cleavage, degradation, and sulfate accumulation; both ester and ether cleavage were probably employed in SLES anoxic degradation by strain S11.
Original languageEnglish
Pages (from-to)5163-5173
Number of pages11
JournalApplied Microbiology and Biotechnology
Issue number12
Publication statusPublished - 2017


  • international


Dive into the research topics of 'Sodium lauryl ether sulfate (SLES) degradation by nitrate-reducing bacteria'. Together they form a unique fingerprint.

Cite this