BIODEGRADATION OF TETRACYCLINE BY BASIDIOMYCETE FUNGUS PLEUROTUS OSTREATUS

Background and Aim:Nowadays, widespread use of pharmaceuticals in modern medicine has been raised as an environmental hot topic which is called them as emerging contaminants. Among diverse group of pharmaceuticals, antibiotics as over the counter therapeutic drugs, has aroused much public health attention. The most important following threat is easily spread of antibiotic-resistant bacteria through different routes as not completely metabolized drugs via excretion to the wastewater. To avoid the entry of these compounds into the land and human food chain, finding a suitable method which is capable of antibiotic degradation before entering to the environment can be afforded.Methods:In this way, a study was conducted to investigate the biodegradability of tetracycline by Pleurotus ostreatus fungi in potato dextrose broth. The experimental factors consisted of inoculated and noninoculated treatments with P. ostreatus), three concentrations of tetracycline (0, 50 and 100 µgml-1) and three times (4, 7, 10 days).Tetracycline removal from the medium was detected by LC-MS/MS analysis. Fungal laccase and peroxidase activity as involved degrading agents were also monitored during the experiment.Results:Results showed P. ostreatus was capable of suppressing 50 µgml-1 tetracycline within earlier than 4 days to undetectable concentrations. Almost Complete removal of tetracycline at 100 µgml-1 was occurred within the first 4 days of incubation. Whereas in noninoculated treatments just negligible removal of 9% tetracycline at 100 µgml-1 up to the end of the experiment was detected. Steady increase in enzymatic activity was simultaneously occurred during the experiment.Conclusion:All evidences coincide with significant degradation capability of P. ostreatus.

کلیدواژه ها:

Biodegradation ، Tetracycline ، P. ostreatus ، Laccase ، peroxidase