This study aimed to evaluate the feasibility of hyperthermophilic anaerobic digestion at 70 °C in the pretreatment of spiramycin fermentation residue. By feeding municipal excess sludge under a solid retention time of 5 days, the hyperthermophilic digester was successfully started up within 3 days from mesophilic digestion by a one-step temperature increase from 35 to 70 °C. MiSeq sequencing showed the fast establishment of thermophilic fermenting bacterial communities in 3 days immediately after the temperature increase, with increases in abundance of Coprothermobacter, Spirochaetaceae_uncultured and Fervidobacterium from <0.001%, 1.06% and <0.001% to 33.77%, 11.65% and 3.42%, respectively. The feasibility of hyperthermophilic digestion for spiramycin residue was evaluated in batch experiments for 7 days. Hyperthermophilic digestion considerably reduced antibiotic concentrations, with removal efficiencies of 55.3% and 99.0% for the spiramycin residue alone and its mixture with hyperthermophilic sludge, respectively. At the same time, the abundances of four macrolide-lincosamide-streptogramin resistance genes were also reduced within 7 days, due to the decrease of their corresponding hosts. These results suggest that hyperthermophilic digestion could easily be started up from mesophilic digestion and might be a suitable pretreatment approach for spiramycin residue.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.