Case Studie

Tandem Mass Tags quantitative proteomics

Indole metabolism mechanisms in a new, efficient indole-degrading facultative anaerobe isolate Enterococcus hirae GDIAS-5

Journal：Journal of Hazardous Materials Impact Factor：13.6 Time：2022 Author Affiliation：Guangdong Academy of Agricultural Sciences

Introduction

Indole is an inter-species and inter-kingdom signaling molecule widespread in the natural world. A large amount of indole in livestock wastes makes it difficult to be degraded, which causes serious malodor. Identifying efficient and eco-friendly ways to eliminate it is an urgent task for the sustainable development of husbandry.While bioconversion is a widely accepted means, the mechanism of indole microbial degradation is little understood, especially under anaerobic conditions.

Purpose

The aim of this study is to identify a new strain of bacteria that can efficiently degrade indole and further analyse the mechanisms of indole oxidation, potential electron acceptors and downstream metabolism to provide new targets and strategies for further synthetic bioreconstruction of indole-degrading bacteria.

Fig.1 Research ideas

Fig.2 Genomic and proteomic analysis of Enterococcus hirae GDIAS-5

Conclusion

In this study, a new isolate of Enterococcus haynesi, GDIAS-5, was found to be effective in degrading 100 mg/L indole within 28h aerobically or 5d anaerobically. Fe(III) is critical for indole degradation by GDIAS-5 and may act as a potential electron acceptor for indole oxidation. The indole oxygenase ycnE was successfully heterologously expressed and purified. The indole-oxindole-isatin reaction catalyzed by ycnE was identified here for the first time.Isatin was converted into catechol, which was further degraded through meta-cleavage. The major innovations exhibited in this study were the characterization of a facultative anaerobic strain with high-efficiency indole degradation and the identification of a new indole oxygenase. These findings suggest a possible new indole metabolic process and mechanism in indole microbial biodegradation.

Reference

Deng JJ, Deng D, Wang ZL,et al. Indole metabolism mechanisms in a new, efficient indole-degrading facultative anaerobe isolate Enterococcus hirae GDIAS-5[J]. J Hazard Mater, 2022.