Efficient degradation of tylosin by Klebsiella oxytoca TYL-T1

Tylosin is widely used in livestock; however, the release of tylosin through animal manure can cause serious environ-mental problems. In this study, a new tylosin-degrading strain, TYL-T1, was isolated. Its phylogenetic similarity to Klebsiella oxytoca was found to be 99.17 %. TYL-T1 maintained good growth at 40 degrees C over a broad pH range (4.0-10 ). TYL-T1 degraded 99.34 % of tylosin in 36 h under optimal conditions (tylosin initial concentration: 25 mg/L, pH: 7.0, and temperature: 35 degrees C). After LC-MS-MS analysis, a new degradation pathway for tylosin was pro-posed, including ester bond breaking of the macrolide lactone ring, redox reaction, and loss of mycinose and mycarose. Based on a transcriptome analysis, 164 genes essential for degradation were upregulated through hydrolysis and redox of tylosin. Among various transferases, lipopolysaccharide methyltransferase, glycogen glucosyltransferase, and fructotransferase were responsible for tylosin degradation. The present study revealed the degradation mechanism of tylosin and highlighted the potential of Klebsiella oxytoca TYL-T1 to remove tylosin from the environment.

Automated summary

In this study, a new tylosin-degrading strain, TYL-T1, was isolated and its degradation mechanism was revealed through transcriptome and metabolite analysis. The results demonstrate the potential of TYL-T1 in removing tylosin from the environment.