一株红霉素降解菌Penicillium sp.ERY-1的筛选、降解特性及其应用研究OA北大核心CSTPCD

The use of green,efficient,and inexpensive microbial agents to eliminate antibiotic residues in fishery wastewater is important for ensuring the quality and ecological environment of aquatic products.To obtain erythromycin-degrading microbes that can be applied to fishery aquaculture wastewater,an erythromycin-degrading fungus was isolated using traditional methods and identified by morphological observation and internal transcribed spacer(ITS)sequence analysis.The optimal temperature and pH for erythromycin degradation were determined using single-factor tests,with the degradation rate as the indicator.The degradation metabolites of erythromycin were identified using ultra-high-performance liquid chromatography-tandem high-resolution electrospray ionization mass spectrometry.A zebrafish challenge test was performed to evaluate the biological safety of the strain.An ecological agent capable of degrading erythromycin was prepared through solid-state fermentation using the optimized parameters.This agent has been used to remediate erythromycin residues in aquaculture wastewaters.The results showed that strain ERY-1 is a member of Penicillium.The optimal conditions for erythromycin degradation by the strain ERY-1 were 20-35℃and pH 5-7.Under these conditions,over 97％of erythromycin with an initial concentration of 1.0 mg·L-1 was degraded.Five potential erythromycin degradation products were identified in this study.Erythromycin gradually loses its antibacterial activity due to dehydration,cladinose removal,and ring cleavage.Strain ERY-1 is relatively safe for aquatic organisms.The mass ratio of rice husk,wheat bran,and corn flour(m꞉m꞉m)was 1:1:1,which was used as the substrate for fermentation.The ratio of material to water was 1 g:1 L,and the initial inoculation ratio was 0.75％.Under such circumstances,a microbial ecological agent with a spore yield of approximately 9.14×109 cfu·g-1 was obtained after 13 days of fermentation at 25℃.The concentration of residual erythromycin is undetectable(below the detection limit of 0.2 ng·L-1)after 3 days since application of this microbiological ecological agent into the erythromycin-contaminated aquaculture wastewater.The results showed that strain ERY-1 could effectively remediate erythromycin-contaminated aquaculture wastewater,and that the microbial ecological agent derived from this strain showed good application and promotion value.