Cyanobacterial degradation of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D): Its response to the oxidative stress induced by the primary degradation product 2,4-dichlorophenol (2,4-DCP)

Excessive use of herbicides in agricultural fields has become a major environmental concern due to the negative effects on the ecosystem. Microbial degradation has been well-known as an effective approach for combating such non-natural substances in soil. In the present study, the degradation of 2,4-Dichlorophenoxyacetic acid (2,4-D) as a result of metabolic activities of a cyanobacterium Nostoc muscorum Meg 1 was investigated using GC–MS analysis. After seven days of 2,4-D exposure, the main residue obtained was 2,4-dichlorophenol (2,4-DCP) at RT: 8.334 (confirmed using NIST library). The effects of 2,4-DCP were studied in a cyanobacterium Nostoc muscorum Meg 1 isolated from a rice field where 2,4-D is commonly used. Exposure to 2,4-DCP at 20, 40, and 80 ppm significantly increased ROS production in the cyanobacterium by 74, 107, and 211 % (p