Evaluation of Cefixime Toxicity Treated With Sono-electro-Fenton Process by Bioassay Using Microorganisms

The aim of this study was to determine the toxicity of cefixime in the inlet solution and effluent treated with the sono-electro-Fenton process using standard strains of microorganisms. This research was performed as an experimental study, which was conducted on a laboratory scale. The standard strains of Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) were used for bioassay. First, the stock solution of ۱۰۰۰ mg/L containing Cefixime was prepared, and for each bacterium (gram-positive and gram-negative), ۵ samples from the inlet solution of the reactor and ۵ samples from effluent treated with the sono-electro-Fenton process were collected under optimal conditions. Finally, each sample was transferred to ۱۰ mL of sterile lactose broth, and a loop of E. coli or S. aureus was dissolved in each sample. Toxicity changes were investigated by calculating the percentage of growth inhibition. The results showed that after ۱۰ hours, the growth rate of both bacteria in the control and the effluent samples was higher, while the growth of bacteria in the inlet solution was lower and had higher toxicity. Based on the results of the study, the toxicity rate for E. coli was reduced from ۷۰% in the inlet solution to ۹.۳% in the effluent (۸۶.۷% reduction in toxicity), and in the case of S. aureus, it was diminished from ۲۵.۳% in the inlet solution to ۷% in the effluent (۷۲.۳% reduction in toxicity) after ۱۰ hours. Based on the results of the present study, bioassay using microorganisms is an effective and useful method to study changes in the toxicity of cefixime.

Keywords:

Cefixime , Toxicity , Sono-electro-Fenton , Bioassay , Microorganism