Efficient biodegradation of flurochloridone herbicide by Streptomyces parvus strain F-G-2 and its degradation mechanism

Flurochloridone (FLC) is a pyrrolidone herbicide with good weed control effects. However, it poses potential threats to the ecological environment and human health. To alleviate the impact of FLC residues, a bacterium capable of degrading FLC, Streptomyces sp. F-G-2, was isolated from FLC-contaminated soil. Within 42 days (d), the strain F-G-2 metabolizes 80.0 % of FLC, there is a significant selective degradation trend towards the enantiomers (-)-(3S, 4S)-FLC and (+)-(3R, 4R)-FLC in degradation. The strain's introduction into soil does not affect the structure and diversity of the indigenous microbial community. Two enzymes responsible for FLC degradation in the strain F-G-2 were identified: α/β hydrolase and 2-hydroxy acid dehydrogenase, with key residues ILE-14 and LYS-187 playing a role. LC-MS/MS analysis confirmed FLC hydrolysis through carbonyl bonds. These findings enhance our understanding of the molecular mechanisms of FLC biodegradation and provide a theoretical basis for environmental remediation in the Qinghai-Tibet Plateau (QTP).