Bioconversion of toxic micropollutant triclosan to 2,4-dichlorophenol using a wastewater isolate Pseudomonas aeruginosa KS2002

Abstract

Triclosan, a commonly available pesticide, has emerged as a ubiquitous pollutant posing a major threat to the environment. Here we have isolated a wastewater microorganism, Pseudomonas aeruginosa KS2002, capable of converting triclosan to 2,4-dichlorophenol within 96 h of incubation. The confirmation of the end product was done using Fourier transform infrared spectroscopy and mass spectroscopy. Different minimal media were investigated to establish a suitable media supporting maximum triclosan degradation. Spectral analysis showed that this bacterial isolate degraded 99.89% ± 0.3 of 2 g/L of triclosan spiked in an M9 minimal salt medium. This isolate utilized fructose and glycerol as a co-substrate to enhance degradation process. The cell-free extract of Pseudomonas aeruginosa KS2002 showed the activity of catechol 2,3-dioxygenase enzyme (specific enzyme activity = 0.161 U/mg). In the presence of 3-fluorocatechol, a meta-cleavage enzyme inhibitor, triclosan degradation was ceased suggesting a meta-cleavage pathway for triclosan degradation. Keeping in view the observations recorded, we proposed a pathway for partial triclosan degradation using this isolate.