Differences in microbial communities and phosphorus cycles between rural and urban lakes: Based on glyphosate and AMPA effects.

Abstract

The widespread availability of glyphosate in shallow lakes is of significant concern. Glyphosate is an organophosphorus pesticide that can affect the phosphorus cycle and microbial communities in lakes. However, the effects of glyphosate on lakes in different geographical locations remain unclear. This study not only investigated glyphosate and aminomethylphosphonic acid (AMPA) residues in sediments from rural and urban lakes, but also examined differences in the effects of these substances on lake microbial communities and phosphorus cycles. Glyphosate and AMPA were detected in 100% of sediments from the three rural and three urban lakes surveyed. Glyphosate concentrations were not significantly different among all lake sediments; however, AMPA concentrations were significantly higher in rural lake sediments than in urban lake sediments (P < 0.05). The abundance of the glpC gene, encoding an organophosphorus-degrading enzyme, and the abundance of Luteitalea sp. TBR-22, which is enriched for the glpC gene, were significantly different between rural and urban lake sediments (P < 0.05). Notably, the abundance of glpC and Luteitalea sp. TBR-22 was significantly and positively correlated with AMPA concentration (P < 0.05). In addition, the AMPA concentration was significantly and positively correlated with the O-bonded inorganic phosphate (Pi) content (P < 0.05). These results suggest that high AMPA concentrations in rural lake sediments may increase the production of O-bonded Pi in lake sediments by controlling the expression of glpC in Luteitalea sp. TBR-22, leading to higher concentrations of O-bonded Pi in the rural lake sediments than in the urban lake sediments.