A study towards minimising tylosin concentration and antibiotic resistance genes in tylosin fermentation dreg fertilizer

This study proposed a comprehensive treatment plan consisting of high temperature + oxidant pre-treatment before compost and thermal treatment after compost to realise the compost resource utilisation of tylosin fermentation dreg. The study revealed that the tylosin concentration in the dregs was reduced by 97.1% under the optimal pre-treatment conditions. Subsequently, high-temperature compost was performed by adding compost auxiliary materials and the content of tylosin in the compost material was below the detection limit ( < 1 mg/kg) after 15 days. During the whole aerobic fermentation process, 70.8% of tylosin removal in the compost material was contributed by microbial metabolism, 23.0% was caused by high-temperature destruction of the compost, and 5.4% was due to the natural decomposition of tylosin. Finally, the finished compost product was further thermal-treated at 130 degrees C for 2 h, which could destroy the antibiotic resistance genes and maintain the seed germination index of the obtained fertiliser > 80%, indicating the low plant toxicity of the compost. Based on this information, the tylosin fermentation dreg composting comprehensive treatment scheme proposed in this study is a safe, efficient and feasible resource utilisation scheme for tylosin fermentation dreg.