College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China.
Faculty of Bioscience Engineering, Ghent University Campus Kortrijk, Graaf Karel de Goedelaan 5, 8500, Kortrijk, Belgium.
Environ Pollut. 2020 May;260:114012. doi: 10.1016/j.envpol.2020.114012. Epub 2020 Jan 22.
Glyphosate, one of the most popular herbicides, has become a prominent aquatic contaminant because of its huge usage. The eco-safety of glyphosate is still in controversy, and it is inconclusive how glyphosate influences aquatic microbial communities. In the present study, the effects of glyphosate on the structure and function of microbial communities in a freshwater microcosm were investigated. 16S/18S rRNA gene sequencing results showed that glyphosate treatment (2.5 mg L, 15 days) did not significantly alter the physical and chemical condition of the microcosm or the composition of the main species in the community, but metatranscriptomic analyses indicated that the transcriptions of some cyanobacteria were significantly influenced by glyphosate. The microbial community enhanced the gene expression in pathways related to translation, secondary metabolites biosynthesis, transport and catabolism to potentially withstand glyphosate contamination. In the low phosphorus (P) environment, a common cyanobacterium, Synechococcus, plays a special role by utilizing glyphosate as P source and thus reducing its toxicity to other microbes, such as Pseudanabaena. In general, addition of glyphosate in our artificial microcosms did not strongly affect the aquatic microbial community composition but did alter the community's transcription levels, which might be potentially explained by that some microbes could alleviate glyphosate's toxicity by utilizing glyphosate as a P source.
草甘膦是一种应用广泛的除草剂，由于其大量使用，已成为一种突出的水生污染物。草甘膦的生态安全性仍存在争议，其对水生微生物群落的影响尚无定论。本研究调查了草甘膦对淡水微宇宙中微生物群落结构和功能的影响。16S/18S rRNA 基因测序结果表明，草甘膦处理（2.5mg/L，15 天）并未显著改变微宇宙的理化条件或群落中的主要物种组成，但宏转录组分析表明，草甘膦显著影响了一些蓝细菌的转录。微生物群落增强了与翻译、次生代谢物生物合成、运输和分解代谢相关的途径中的基因表达，以潜在地抵御草甘膦污染。在低磷（P）环境中，一种常见的蓝细菌聚球藻通过利用草甘膦作为 P 源发挥特殊作用，从而降低其对其他微生物（如伪鱼腥藻）的毒性。总的来说，在我们的人工微宇宙中添加草甘膦并没有强烈影响水生微生物群落的组成，但确实改变了群落的转录水平，这可能可以解释为一些微生物可以通过利用草甘膦作为 P 源来减轻草甘膦的毒性。
