Complete biodegradation of glyphosate with microbial consortium YS622: Structural analysis, biochemical pathways, and environmental bioremediation

Abstract

The large-scale use of glyphosate has led to the continuous accumulation of residues in the environment, disrupting ecological balance and posing a threat to human health. The main objective of this study was to investigate the potential role of microbial consortium YS622 for the bioremediation of glyphosate-contaminated water/soil environments. YS622 could degrade 100 % of 50 mg/L glyphosate within 36 h, an efficiency higher than that of any other consortia or pure microorganisms reported so far. The kinetic parameters of maximum specific degradation rate, half-rate constant, and inhibition coefficient were determined to be 0.2 h−1, 139.0 mg/L, and 25.1 mg/L, respectively. YS622 metabolized glyphosate via the aminomethylphosphonic acid pathway via breaking the C–N bond. In addition, the sequencing analysis revealed that Azospirillum, Cloacibacterium, and Ochrobactrum were the dominant genera of YS622 in the degradation process, indicating that these genera might play pivotal roles in glyphosate biodegradation. Furthermore, the inoculation of YS622 in both sterilized and unsterilized water–sediment systems significantly promoted the degradation of glyphosate, with over 97 % degradation of 60 mg/L glyphosate within 36 h. The discovery of YS622 fills a gap in the synergistic metabolism of glyphosate at the community level and provides a potential candidate for bioremediation applications.