Quorum Quenching of Nitrobacter winogradskyi Suggests that Quorum Sensing Regulates Fluxes of Nitrogen Oxide(s) during Nitrification.
Quorum Quenching of Nitrobacter winogradskyi Suggests that Quorum Sensing Regulates Fluxes of Nitrogen Oxide(s) during Nitrification.
复制标题
硝基杆菌Winogradskyi的法定淬火表明，法定人数在硝化过程中调节氮氧化物的通量。
DOI：
10.1128/mbio.01753-16
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发表时间：
2016-10-25
期刊：
影响因子：
6.4
通讯作者：
Sayavedra-Soto LA
中科院分区：
文献类型：
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作者：
Mellbye BL;Giguere AT;Bottomley PJ;Sayavedra-Soto LA
群体感应（Quorum sensing， QS）是一种在细菌中广泛存在的过程，通过产生可扩散的化学信号来协调基因表达与细胞密度、扩散动力学和空间分布。迄今为止，大多数关于QS的研究都集中在可接受基因操作和具有高生长速率的模式细菌上，但许多对环境重要的细菌被忽视了。例如，参与硝化作用（通过亚硝酸盐将氨氧化为硝酸盐）的proteobacteria代表产生QS信号，称为酰基-高丝氨酸内酯（AHLs）。硝化作用释放出氧化氮气体（NO、NO2和N2O），这些都是潜在的有害化合物，会导致全球变暖。尽管对硝化作用有相当大的兴趣，但QS在硝化细菌的生理/生态学中的目的却知之甚少。通过群体猝灭方法，我们研究了QS在一种被广泛研究的产生ahl的亚硝酸盐氧化剂硝基杆菌winogradskyi中的作用。我们将重组AiiA内酯酶添加到N. winogradskyi培养物中以降解ahl以防止其积累并诱导qs阴性表型，然后使用mRNA测序（mRNA- seq）鉴定假定的qs控制基因。我们的转录组分析显示，在qs熟练条件下（无活性内酯酶），nirK和nirK簇基因（ncgABC）的表达增加了19.9倍。这些数据使我们怀疑QS是否影响了N. winogradskyi的氮氧化物气体通量。在精通qs的条件下，NOx的产量和消耗增加，N2O的产量减少。群体猝灭转录组方法具有广泛的潜力，可以在非遗传易感性的生物体中识别qs控制的基因和表型。细菌细胞-细胞信号，或群体感应（QS），是细菌通信和基因调控的一种方法，在细菌中得到了很好的研究。然而，人们对QS在许多环境重要细菌中的作用知之甚少。在这里，我们展示了群体猝灭与mRNA-Seq相结合，以鉴定亚硝酸盐氧化细菌Nitrobacter winogradskyi的qs控制基因和表型。亚硝酸盐氧化剂在氮循环中发挥重要作用，通过亚硝酸盐参与硝化作用，即氨的好氧氧化成硝酸盐。我们的群体猝灭方法表明，QS影响N. winogradskyi对环境重要的氮氧化物气体（NO， NO2和N2O）的产生和消耗。这项研究展示了一种研究难以处理微生物的QS的新技术，并表明亚硝酸盐氧化剂也可能有助于硝化依赖的氮氧化物气体的产生，从而导致全球变暖。
Quorum sensing (QS) is a widespread process in bacteria used to coordinate gene expression with cell density, diffusion dynamics, and spatial distribution through the production of diffusible chemical signals. To date, most studies on QS have focused on model bacteria that are amenable to genetic manipulation and capable of high growth rates, but many environmentally important bacteria have been overlooked. For example, representatives of proteobacteria that participate in nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, produce QS signals called acyl-homoserine lactones (AHLs). Nitrification emits nitrogen oxide gases (NO, NO2, and N2O), which are potentially hazardous compounds that contribute to global warming. Despite considerable interest in nitrification, the purpose of QS in the physiology/ecology of nitrifying bacteria is poorly understood. Through a quorum quenching approach, we investigated the role of QS in a well-studied AHL-producing nitrite oxidizer, Nitrobacter winogradskyi. We added a recombinant AiiA lactonase to N. winogradskyi cultures to degrade AHLs to prevent their accumulation and to induce a QS-negative phenotype and then used mRNA sequencing (mRNA-Seq) to identify putative QS-controlled genes. Our transcriptome analysis showed that expression of nirK and nirK cluster genes (ncgABC) increased up to 19.9-fold under QS-proficient conditions (minus active lactonase). These data led to us to query if QS influenced nitrogen oxide gas fluxes in N. winogradskyi. Production and consumption of NOx increased and production of N2O decreased under QS-proficient conditions. Quorum quenching transcriptome approaches have broad potential to identify QS-controlled genes and phenotypes in organisms that are not genetically tractable. Bacterial cell-cell signaling, or quorum sensing (QS), is a method of bacterial communication and gene regulation that is well studied in bacteria. However, little is known about the purpose of QS in many environmentally important bacteria. Here, we demonstrate quorum quenching coupled with mRNA-Seq to identify QS-controlled genes and phenotypes in Nitrobacter winogradskyi, a nitrite-oxidizing bacterium. Nitrite oxidizers play an important role in the nitrogen cycle though their participation in nitrification, the aerobic oxidation of ammonia to nitrate via nitrite. Our quorum quenching approach revealed that QS influences production and consumption of environmentally important nitrogen oxide gases (NO, NO2, and N2O) in N. winogradskyi. This study demonstrated a novel technique for studying QS in difficult-to-work-with microorganisms and showed that nitrite oxidizers might also contribute to nitrification-dependent production of nitrogen oxide gases that contribute to global warming.