Reserving nitrogen in soils through microbial nitrate reduction to ammonium

该项目旨在识别那些能够将硝酸盐转化为铵的微生物，从而增加土壤氮素的保存。施入土壤的肥料中50%以上的氮素流失到环境中，这既是农民的经济损失，也是氮素污染的主要人为来源。一些微生物可以通过异化还原(DNRA)将硝酸盐转化为铵，从而增加土壤氮素保留量。然而，DNRA的过程和负责的微生物群在很大程度上仍然不清楚。该项目计划使用同位素示踪和生物分子方法来鉴定这些DNRA微生物群，并阐明DNRA反应过程。这一发现可能支持使用DNRA来改善土壤氮素。

This project aims to identify those microbes able to transform nitrate to ammonium and thus increase soil nitrogen conservation. More than 50 per cent of the nitrogen in fertilisers applied to soils is lost into the environment, which is both a financial loss to farmers and a main anthropogenic source of nitrogen pollution. Some microbes can transform nitrate into ammonium through dissimilatory reduction (DNRA) and thus increase soil nitrogen retention. However, the DNRA process and the responsible microbial groups remain largely unknown. This project plans to use isotope tracing and biomolecular approaches to identify those DNRA microbial groups and elucidate the DNRA reaction process. The findings may support the use of DNRA to improve soil nitrogen.