Liang Xiaolong, Wagner Regan E, Li Bingxue, Zhang Ning, Radosevich Mark
Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, Knoxville, TN, United States.
College of Land and Environment, Shenyang Agricultural University, Shenyang, China.
Front Microbiol. 2020 Jun 10;11:1287. doi: 10.3389/fmicb.2020.01287. eCollection 2020.
Cell-density dependent quorum sensing (QS) is fundamental for many coordinated behaviors among bacteria. Most recently several studies have revealed a role for bacterial QS communication in bacteriophage (phage) reproductive decisions. However, QS based phage-host interactions remain largely unknown, with the mechanistic details revealed for only a few phage-host pairs and a dearth of information available at the microbial community level. Here we report on the specific action of eight different individual QS signals (acyl-homoserine lactones; AHLs varying in acyl-chain length from four to 14 carbon atoms) on prophage induction in soil microbial communities. We show QS autoinducers, triggered prophage induction in soil bacteria and the response was significant enough to alter bacterial community composition . AHL treatment significantly decreased the bacterial diversity (Shannon Index) but did not significantly impact species richness. Exposure to short chain-length AHLs resulted in a decrease in the abundance of different taxa than exposure to higher molecular weight AHLs. Each AHL targeted a different subset of bacterial taxa. Our observations indicate that individual AHLs may trigger prophage induction in different bacterial taxa leading to changes in microbial community structure. The findings also have implications for the role of phage-host interactions in ecologically significant processes such as biogeochemical cycles, and phage mediated transfer of host genes, e.g., photosynthesis and heavy metal/antibiotic resistance.
细胞密度依赖性群体感应（QS）对于细菌间许多协调行为至关重要。最近的几项研究揭示了细菌QS通讯在噬菌体（phage）繁殖决策中的作用。然而，基于QS的噬菌体 - 宿主相互作用在很大程度上仍然未知，仅对少数噬菌体 - 宿主对揭示了其机制细节，且在微生物群落水平上可用信息匮乏。在这里，我们报告了八种不同的个体QS信号（酰基高丝氨酸内酯；酰基链长度从四个到14个碳原子不等的AHLs）对土壤微生物群落中前噬菌体诱导的具体作用。我们表明QS自诱导物在土壤细菌中触发了前噬菌体诱导，并且这种反应足以显著改变细菌群落组成。AHL处理显著降低了细菌多样性（香农指数），但对物种丰富度没有显著影响。与暴露于高分子量AHLs相比，暴露于短链长度AHLs导致不同分类群的丰度下降。每种AHL靶向不同的细菌分类群子集。我们的观察结果表明，个体AHLs可能在不同细菌分类群中触发前噬菌体诱导，从而导致微生物群落结构的变化。这些发现对于噬菌体 - 宿主相互作用在生态重要过程（如生物地球化学循环）以及噬菌体介导的宿主基因转移（例如光合作用和重金属/抗生素抗性）中的作用也具有启示意义。
