Aerobic biotransformation of n-tetradecylbenzyldimethylammonium chloride by an enriched Pseudomonas spp. community.
The biotransformation of n-tetradecylbenzyldimethylammonium chloride (C(14)BDMA-Cl), a quaternary ammonium compound (QAC), under aerobic conditions by an enriched microbial community growing on benzalkonium chlorides (BACs) was investigated. Biotransformation of C(14)BDMA-Cl commenced with cleavage of the C(alkyl)-N bond and formation of benzyldimethylamine (BDMA). BDMA was further degraded, but in contrast to a previously reported BAC biotransformation pathway, neither benzylmethylamine (BMA) nor benzylamine (BA) was detected as a BDMA biotransformation product. Kinetic assays further confirmed that BMA and BA were not intermediates of C(14)BDMA-Cl transformation by the enriched community. Thus, BDMA is thought to be transformed to dimethylamine and benzoic acid via debenzylation. The biomass-normalized rate of C(14)BDMA-Cl biotransformation was 0.09 μmol/[mg of volatile suspended solids (VSS)·h]. The Microtox acute toxicity EC(50) value of BDMA was 500 times higher than that of C(14)BDMA-Cl. Thus, the aerobic biotransformation of C(14)BDMA-Cl to BDMA results in substantial toxicity reduction. Phylogenetic analysis of Bacteria diversity indicated that the majority of the sequenced clones (98% of the clone library) belonged to the genus Pseudomonas.
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, United States.
Ulas
U
Tezel
Madan
M
Tandukar
Robert J
RJ
Martinez
Patricia A
PA
Sobecky
Spyros G
SG
Pavlostathis
D000332:Aerobiosis; D001711:Biotransformation; D010802:Phylogeny; D011549:Pseudomonas / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*
D000644:Quaternary Ammonium Compounds; C576776:n-tetradecylbenzyldimethylammonium chloride