Biodegradation of benzalkonium chlorides singly and in mixtures by a Pseudomonas sp. isolated from returned activated sludge.
Bactericidal cationic surfactants such as quaternary ammonium compounds (QACs) are widely detected in the environment, and found at mg kg(-1) concentrations in biosolids. Although individual QACs are amenable to biodegradation, it is possible that persistence is increased for mixtures of QACs with varying structure. The present study evaluated the biodegradation of benzyl dimethyl dodecyl ammonium chloride (BDDA) singly and in the presence of benzyl dimethyl tetradecyl ammonium chloride (BDTA) using Pseudomonas sp., isolated from returned activated sludge. Growth was evaluated, as was biodegradation using (14)C and HPLC-MS methods. BDTA was more toxic to growth of Pseudomonas sp. compared to BDDA, and BDTA inhibited BDDA biodegradation. The benzyl ring of [U-(14)C-benzyl] BDDA was readily and completely mineralized. The detection of the transformation products benzyl methyl amine and dodecyl dimethyl amine in spent culture liquid was consistent with literature. Overall, this study demonstrates the antagonistic effect of interactions on biodegradation of two widely used QACs suggesting further investigation on the degradation of mixture of QACs in wastewater effluents and biosolids.
Department of Chemical and Biochemical Engineering, University of Western Ontario, London, ON N6A 5B9, Canada. Electronic address: akhan462@uwo.ca.
Adnan Hossain
AH
Khan
Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada; Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada. Electronic address: Ed.Topp@AGR.GC.CA.
Edward
E
Topp
Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada. Electronic address: Andrew.Scott@AGR.GC.CA.
Andrew
A
Scott
Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada. Electronic address: Mark.Sumarah@agr.gc.ca.
Mark
M
Sumarah
Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada. Electronic address: smacfie@uwo.ca.
Sheila M
SM
Macfie
Department of Chemical and Biochemical Engineering, University of Western Ontario, London, ON N6A 5B9, Canada. Electronic address: mbhowmic@uwo.ca.
Madhumita B
MB
Ray
D001548:Benzalkonium Compounds / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D013058:Mass Spectrometry; D011549:Pseudomonas / Q000378:metabolism*; D012722:Sewage
D001548:Benzalkonium Compounds; D012722:Sewage
Benzalkonium chloride; Benzyl dimethyl dodecyl ammonium chloride; Benzyl dimethyl tetradecyl ammonium chloride; Biodegradation; Cationic surfactant