Glyphosate Shapes a Dinoflagellate-Associated Bacterial Community While Supporting Algal Growth as Sole Phosphorus Source.
Glyphosate Shapes a Dinoflagellate-Associated Bacterial Community While Supporting Algal Growth as Sole Phosphorus Source.
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草甘膦形成甲藻相关细菌群落，同时作为唯一磷源支持藻类生长
DOI：
10.3389/fmicb.2017.02530
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发表时间：
2017
影响因子：
5.2
通讯作者：
Lin S
中科院分区：
文献类型：
--
作者：
Wang C;Lin X;Li L;Lin L;Lin S
草甘膦是一种广泛使用的除草剂，当排入沿海海洋时，它可能成为浮游植物和微生物的磷 (P) 来源。与细菌相反，很少有真核浮游植物能够直接利用草甘膦。在这项研究中，我们观察到，经过长时间的延迟（> 60天），东海原甲藻（一种已知会在东海引起主要有害藻华的甲藻）可以在以草甘膦作为唯一磷源的培养基中生长；表明东海 P. donghaiense 的生长是通过细菌介导的。为了了解细菌群落对草甘膦的反应，我们分析了东海原虫培养物在较低（36 μM）和较高（360 μM）草甘膦浓度下生长时存在的微生物群落的 16S rRNA 基因。基于Sanger和Illumina高通量测序，我们获得了超过55,323条优质序列，分为六门。随着草甘膦浓度的升高，我们的结果显示变形菌门和厚壁菌门显着增加，而拟杆菌门减少。进一步的 qPCR（定量 PCR）分析显示，与低草甘膦和无草甘膦培养物相比，高草甘膦东海 P. donghaiense 培养物中两种特定系统型的丰度更高。相应地，qPCR 显示了 phnJ 的 γ 变形菌类型丰度的相同趋势，phnJ 是编码 α-D-核糖 1-甲基膦酸 5-磷酸 C-P 裂合酶的基因，负责磷酸盐降解。此外，基于我们的 16S rRNA 基因序列的 Tax4Fun 分析导致草甘膦处理的培养物中膦酸代谢基因的预测丰度更高。这项研究表明，草甘膦可以选择性地促进藻类培养物中和富含草甘膦的沿海水域中特定细菌群的生长，这种相互作用可能进一步促进藻类的生长。
Glyphosate is a widely used herbicide that can potentially be a phosphorus (P) source for phytoplankton and microbes when discharged into the coastal ocean. In contrast to bacteria, few eukaryotic phytoplankton species appear capable of directly utilizing glyphosate. In this study, we observed, after a long delay (>60 days), Prorocentrum donghaiense, a dinoflagellate known to cause major harmful algal blooms in the East China Sea, could grow in a medium with glyphosate as the sole P source; suggesting that P. donghaiense growth was through bacterial mediation. To understand how the bacteria community might respond to glyphosate, we analyzed the 16S rRNA genes of the microbial community present in P. donghaiense cultures when grown under lower (36 μM) and higher (360 μM) glyphosate concentrations. Based on both Sanger and Illumina high throughput sequencing, we obtained more than 55,323 good-quality sequences, which were classified into six phyla. As the concentration of glyphosate rose, our results showed a significant increase in the phyla Proteobacteria and Firmicutes and a decrease in the phylum Bacteroidetes. Further qPCR (Quantitative PCR) analysis showed higher abundances of two specific phylotypes in the higher-glyphosate P. donghaiense cultures when compared to the lower-glyphosate and no-glyphosate cultures. Correspondingly, qPCR displayed the same trend for the abundance of a gammaproteobacterial type of phnJ, a gene encoding Alpha-D-ribose 1-methylphosphonate 5-phosphate C-P lyase, which is responsible for phosphonate degradation. In addition, Tax4Fun analysis based on our 16S rRNA gene sequences results in higher predicted abundances of phosphonate metabolizing genes in glyphosate-treated cultures. This study demonstrates that glyphosate could selectively promote the growth of particular groups of bacteria within an algal culture and in glyphosate enriched coastal waters, this interaction may potentially further facilitate the growth of alga.