Unraveling community structure, ecophysiology, and regulation of new acid-tolerant denitrifiers driving high N2O emissions from cryoturbated peat soil in acidic tundra

在北极苔原冷扰动泥炭圈是“热点”的N2O排放，而邻近的unturbated泥炭网站没有。这种受永冻影响的系统预计将对全球变暖作出反应，并孕育新的耐酸杀菌剂。虽然反硝化作用是一个主要的N2O在泥炭地的来源，和反硝化剂有助于控制N2O的排放，在cryoturbated和unturbated泥炭的生态生理和空间分布的活性反硝化剂基本上是未知的。因此，与N2O排放相关的活性生物的垂直和水平分布，以及实验变暖对这些生物体的影响将通过结构基因和转录本定向条形码扩增子焦磷酸测序和qPCR，最可能的数量，总细胞计数，缩影和N2O通量测量来解决。异化硝酸盐还原剂（DNRA）可能会释放N2O，同样也会进行评估。新的活性关键结构基因的细菌，真菌和真菌的相对重要性将确定的“双RNA方法”和“消减转录组学”。“基于RNA和DNA稳定同位素探针的焦磷酸测序区分法”将用于阐明与活性有机酸同化酶和DNRA的结构基因共存的16S rRNA基因。通过结构基因和转录本指导的qPCR以及过程分析，将在微观世界中评估温度、O2和pH对新澄清剂的调节。将通过定向培养策略分离和表征新的发酵剂。

Cryoturbated peat circles in arctic tundra are ‘hot spots’ of N2O emission, while adjacent unturbated peat sites are not. Such permafrost-affected systems are projected to react to global warming and harbor new acid-tolerant denitrifiers. Although denitrification is a major source of N2O in peatlands, and denitrifiers contribute to the control of N2O emissions, the ecophysiology and spatial distribution of active denitrifiers in cryoturbated and unturbated peat is essentially unknown. Thus, the vertical and horizontal distribution of active denitrifiers associated with N2O emissions, and the effect of experimental warming on such organisms will be addressed by structural gene and transcript directed barcoded amplicon pyrosequencing and qPCR, most probable numbers, total cell counts, microcosms, and N2O-flux measurements in the field. Dissimilatory nitrate reducers (DNRA) might release N2O and will likewise be assessed. New active key structural genes of denitrifiers and the relative importance of Bacteria, Archaea, and Fungi will be determined by the ‘double RNA approach’ and ‘subtractive transcriptomics’. ‘Differentiating pyrosequencing based RNA and DNA stable isotope probing’ will be applied to elucidate 16S rRNA genes concomitant to structural genes of active organic acid assimilating denitrifiers and DNRA. The regulation of new denitrifiers by temperature, O2, and pH will be evaluated in microcosms by structural gene and transcript directed qPCR together with process analyses. New denitrifiers will be isolated and characterized by a directed cultivation strategy.