Differential Degradation and Detoxification of an Aromatic Pollutant by Two Different Peroxidases.
Enzymatic degradation of organic pollutants is a new and promising remediation approach. Peroxidases are one of the most commonly used classes of enzymes to degrade organic pollutants. However, it is generally assumed that all peroxidases behave similarly and produce similar degradation products. In this study, we conducted detailed studies of the degradation of a model aromatic pollutant, Sulforhodamine B dye (SRB dye), using two peroxidases-soybean peroxidase (SBP) and chloroperoxidase (CPO). Our results show that these two related enzymes had different optimum conditions (pH, temperature, H₂O₂ concentration, etc.) for efficiently degrading SRB dye. High-performance liquid chromatography and liquid chromatography -mass spectrometry analyses confirmed that both SBP and CPO transformed the SRB dye into low molecular weight intermediates. While most of the intermediates produced by the two enzymes were the same, the CPO treatment produced at least one different intermediate. Furthermore, toxicological evaluation using lettuce (Lactuca sativa) seeds demonstrated that the SBP-based treatment was able to eliminate the phytotoxicity of SRB dye, but the CPO-based treatment did not. Our results show, for the first time, that while both of these related enzymes can be used to efficiently degrade organic pollutants, they have different optimum reaction conditions and may not be equally efficient in detoxification of organic pollutants.
Department of Biology, United Arab Emirates University, P.O. BOX 15551, Al-Ain, UAE. 200907889@uaeu.ac.ae.
Aysha Hamad
AH
Alneyadi
Department of Chemistry, United Arab Emirates University, P.O. BOX 15551, Al-Ain, UAE. altafshah@uaeu.ac.ae.
Iltaf
I
Shah
Department of Biology, United Arab Emirates University, P.O. BOX 15551, Al-Ain, UAE. sabuqamar@uaeu.ac.ae.
Synan F
SF
AbuQamar
Department of Chemistry, United Arab Emirates University, P.O. BOX 15551, Al-Ain, UAE. salman.ashraf@uaeu.ac.ae.
Syed Salman
SS
Ashraf
D001673:Biodegradation, Environmental; D002711:Chloride Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D012235:Rhodamines / Q000737:chemistry*; D013025:Glycine max / Q000201:enzymology; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D010940:Plant Proteins; D012235:Rhodamines; D014874:Water Pollutants, Chemical; C022027:lissamine rhodamine B; D006861:Hydrogen Peroxide; D010544:Peroxidases; D002711:Chloride Peroxidase
Sulforhodamine B; chloroperoxidase; enzymatic remediation; organic pollutants; soybean peroxidase