Overuse of herbicide chlorimuron-ethyl (CE) brings ecological risks to natural ecosystems. Microbial consortium, a natural community of microbes or a man-made microbial co-culture, has shown great potential in bio-remediation of herbicide-polluted environment.

Using CE-contaminated soil, Prof. ZHANG Huiwen, Prof. XU Mingkai and doctoral student LI Xiang from the Institute of Applied Ecology (IAE) of the Chinese Academy of Sciences (CAS) have recently established a microbial enrichment culture system and obtained a microbial consortium capable of degrading CE.

The researchers found that a microbial consortium, designated as L1, could degrade CE efficiently, and when tested with bioinformatics tools, Methyloversatilis, Pseudoxanthomonas, Methylopila, Hyphomicrobium, Stenotrophomonas and Sphingomonas were the genera most responsible for the degradation of CE. 

In addition, the researchers found cross-feeding, co-metabolic and synergistic relationships between "functional bacteria" with degradation capacity, and even between "functional bacteria" and "auxiliary bacteria" without degradation capacity.

This study clarifies the microbial degradation pathways of chlorimuron-ethyl, and taps new microbial resources for remediation of herbicide-polluted environment. The researchers suggest to optimize the design of consortium models to explore ways to regulate microbial community structure, metabolism and function.

Results entitled "Characterizing the microbial consortium L1 capable of efficiently degrading chlorimuron-ethyl via metagenome combining 16S rDNA sequencing" have been published in Frontiers in Microbiology.

This study was funded by the National Natural Science Foundation of China, the Strategic Priority Research Program of CAS, the Major S&T Achievement Transformation Project of Shenyang Municipal Science and Technology Bureau, and the Doctoral Start-up Fund of Liaoning Province.