Screen and Study of Tetracycline-Degrading Bacteria From Activated Sludge and Granular Sludge

Wastewater treatment cannot effectively remove tetracycline contained in wastewater, and environmental residues accumulate as a result of this condition. Existing methods use to address the high cost of wastewater treatment and other economic and effective means have been explored. Aerobic granular sludge technology is a newly developed potential biological wastewater treatment method, but the removal of tetracycline through this process is limited. Therefore, the collection of tetracycline-degrading bacteria as a biological fortifier is vital. In this experiment, 20 and 24 tetracycline-degrading bacteria are isolated from granular and activated sludge samples, respectively. Highly efficient tetracycline-degrading strains are selected. The effect of these strains on the degradation rate is investigated under the influence of different factors, namely, time, pH, extra carbon source, inoculum concentration of extra nitrogen source, and substrate concentration. Determination of the nucleotide sequence of the gene encoding for 16S rRNA and physiological and biochemical identification shows that two strains belonged to Achromobacter species.