Effects of electrical stimulation based on directed domestication on m-dichlorobenzene purification performance and microbial composition

Herein, a microbial consortia directed domestication approach based on degradation pathways was proposed. This approach employs intermediates capable of promoting ring-opening and dechlorination of m -dichlorobenzene ( m -DCB), in conjunction with m -DCB itself, as substrates for stepwise domestication, with the aim of overcoming the limitation of microbial activity due to the high toxicity of m -DCB. The microbial community analysis for the directed domestication of consortia domesticated that microorganisms responsible for ring-opening and dechlorination were predominant. Meanwhile, the removal efficiency (RE) of m -DCB by directed domestication microbial consortia was significantly higher than the original microbial consortia and abiotic control. To further improve the ring-opening and dechlorination performance of m -DCB, electrical stimulation was introduced as a means of enhancing the directed domestication. Performance tests showed that the highest RE and elimination capacity (EC) of m -DCB were 95.23 % and 23.77 mg/m 3 /h, at an electrical stimulation of 0.7 V, respectively. The microbial community analyses revealed that electrical stimulation led to an increase in the relative abundance of key functional genera (e.g., Rhodanobacter and Pseudomonas ) and functional genes (e.g., catE and dhaA), thereby facilitating the oxidation ring-opening and reductive dechlorination of m -DCB. Metagenomic sequencing further revealed the potential and mechanisms for enhanced biodegradation of m -DCB by the coupled approach of electrical stimulation and directed domestication. The study demonstrates that the biodegradation potential of m -DCB can be enhanced through electrical stimulation based on directed domestication, providing a strategic pathway for microbial construction and improved m -DCB removal from exhaust gases.