• antibiotic;
  • biodegradation;
  • kinetics;
  • solid waste;
  • waste disposal

A large amount of pharmaceutical solid waste (PSW) has been generated in the process of tylosin production using fermentation. This PSW cannot been reused directly because of the existence of residual tylosin. The objective of this study was to investigate the method for biodegradation of tylosin antibiotic in PSW. The results showed that a novel tylosin-degrading strain was isolated from the soil deposited by PSW and identified as Citrobacter amalonaticus. This strain was capable of degrading almost 100% of tylosin in PSW medium with an initial concentration of 50 mg/L after 72 h of incubation under conditions of the initial pH 6.0 and 30°C. The degradation kinetics for tylosin followed a first-order model, and half-lives were 16.16–16.82 h when the initial concentrations of tylosin ranged from 25 to 100 mg/L. These results indicate that the isolated strain has a relatively high ability to degrade tylosin and may be used for bioremediation of the environment contaminated by tylosin waste. © 2014 American Institute of Chemical Engineers Environ Prog, 2014