The contribution of ammonification to N2O emissions from soils

该项目将调查一种称为氨化作用的细菌过程在土壤排放一氧化二氮（N2 O）中的重要性。N2 O可能是最常见的麻醉剂“笑气”。然而，从全球范围来看，一氧化二氮的排放可不是闹着玩的，因为它是一种有效的绿色家用气体，可以在大气中存在数百年。这种气体的全球排放量每年都在上升，其中大部分来自生物来源。由于这种气体参与了全球变暖和平流层臭氧的破坏，这是一个非常令人关注的问题。因此，了解N2 O释放的酶促过程、这些过程的调节以及细菌氨化过程中一氧化二氮释放的微生物性质至关重要。然后，就有可能提出适当的土壤-植物系统管理建议，以减少排放并改进现有模型。这一点很重要，因为氨化作用的适当缓解策略可能不同于另一种称为反硝化的细菌过程，后者也可能导致N2 O排放。在这里，我们将涵盖整个画面的N2 O排放氨化酶从纯化的酶产生的气体，以复杂的社区，港口这些酶在土壤中。我们将使用酶分析和稳定同位素技术来确定氨化速率和N2 O生产在这个过程中，并将使用分子技术来调查土壤中的氨化人口。

This project will investigate the significance of a bacterial process called ammonification in the emmission of nitrous oxide (N2O) from soils. N2O is perhaps most commonly known as the anaesthetic 'laughing gas'. However in global terms emissions of N2O is no laughing matter as it is a potent green house gas that can persist in the atmosphere for hundreds of years. The global emmissions of this gas are rising yearly and much of this is from biological sources. This is of great concern due to the involvement of this gas in global warming and the destruction of stratospheric ozone. Thus it is vital to understand the enzymatic processes that underlie N2O release, the regulation of these processes and the nature of the microorganisms responsible for the nitrous oxide release during bacterial ammonification. It will then be possible to propose appropriate management of the soil-plant system to mitigate emissions and to improve existing models. This is important as appropriate mitigation strategies for ammonification are likely to differ from another bacterial process called denitrification that can also lead to N2O emmission. Here we will encompass the whole picture of N2O emission in ammonifiers from the purified enzymes that produce the gas to complex communities that harbour these enzymes in soil. We will use enzyme analysis and stable isotope techniques to determine ammonification rates and N2O production during this process, and will use molecular techniques to investigate ammonifying populations in soil.