Biodegradation of Tetracycline Antibiotics Residues in Swine Manure

L9(34) orthogonal experiments by simulating the aerated static pile process were carried out to investigate the biodegradation of oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC) residues in swine manure at different incubation temperatures (35.0, 45.0 and 55.0℃), initial moisture contents (40.0%, 60.0% and 75.0%) and time (7, 14 and 21 d). Meanwhile, the microbial community of total heterotrophic microorganisms was analyzed by standard dilution plating of incubation at 28, 45 and 55℃, respectively, for 4 d. The results showed that the biodegradation rates of these three tetracyclines (TCs) would reach the maximum at the conditions of 55.0℃, 60.0% and 14 d. The biodegradation of TCs in swine manure met with the first order kinetics model. Statistical analysis showed that temperature was the major factor of OTC and TC biodegradation, and initial moisture content was the major factor of CTC biodegradation, however, these three factors did not have a significant effect on the biodegradation rate of these TCs and relative ratio of fungi, actinomycete and bacteria, respectively. The bacteria were the predominance during the biodegradation of TCs residue in swine manure.