Response of Burkholderia sp.IDO3 to skatole and downstream metabolic gene analysis
Skatole is a nitrogen containing heterocyclic aromatic pollutant with a strong fecal odor.It is widely distributed in intestines,feces,landfills,and marine environments.It is relatively stable and difficult to degrade.Burkholderia sp.IDO3 was assessed for physiological and biochemical indices under skatole exposure.Downstream metabolic genes were analyzed using RT-qPCR and heterologous gene expression studies.The minimum inhibitory concentration(MIC)of skatole for Burkholderia sp.IDO3 was 1.5 mmol/L.Skatole promotes biofilm formation and hydrophobicity in strain IDO3 in a dose-dependent manner.Oxidative stress experiments revealed that skatole increases superoxide dismutase and catalase activities and inhibits lipid peroxidation(malondialdehyde)and glutathione production.Based on preliminary omics analyses,we speculated that catechol 1,2-dioxygenase(DCN14_04105)may be the key gene involved in downstream metabolism.RT-qPCR showed that this gene was upregulated 3.70-fold under skatole exposure.The gene was expressed in Escherichia coli to obtain pure protein.Pure enzyme experiments revealed an optimal pH of 8.5 and an optimal temperature of 30 ℃.Zn2+,Co2+,Cd2+,Se4+,Sn2+,and Ca2+exhibited inhibitory effects.The Km value was 25.98 μmol/L,and kcat was 10.70 s-1.This study demonstrated the physiological and biochemical properties of Burkholderia sp.IDO3 was used to assess the effect of skatole exposure.The central metabolic pathway of skatole degradation is likely catalyzed by catechol 1,2-dioxygenase.These results provide a new microbial resource for efficient skatole degradation,and facilitate functional studies.
万方数据
维普
