中文摘要：

土壤氮素矿化产生的无机氮是植物的主要氮素来源，土壤氨化过程是氮素矿化的第一步，微生物在其中发挥着巨大作用．本文从氨化过程的微生物作用机理，可利用碳氮比、蛋白酶和微生物群落结构等影响因素以及微生物研究方法3个方面来讨论微生物对氨化过程的重要贡献。研究发现高分子可溶性有机氮的解聚作用很可能是氨化过程的限速步骤，土壤微生物生物量氮有可能是微生物易利用氮的直接且主要来源，同时土壤可利用碳氮比对氨态氮的产生具有重要影响．最后介绍了分子生物学新方法尤其是高通量测序技术在土壤微生物作用研究中的应用，并就目前未解决问题和今后研究方向提出展望．图1参63

英文摘要：

Inorganic nitrogen which comes from soil nitrogen mineralization is the main nitrogen source for plant. Ammonifying process is the first step of nitrogen mineralization, in which microbes play an important role. This paper discussed the effects of microbes in ammonifying process from three aspects： the microbial action mechanism of degrading soil organic nitrogen into ammonia, the influencing factors including available carbon to nitrogen ratio, protease and microbial community structure, and some latest techniques for microbial research. Some researches found that the depolymerization of high molecular weight soluble organic nitrogen is likely the rate-limiting step in ammonifying process; soil microbial biomass nitrogen may be the direct and main source of microbial available organic nitrogen; at the same time, soil available carbon to nitrogen ratio has a significant effect on the production of ammonium. In the end, we introduced some new molecular biology techniques, especially high-throughput sequencing for research of soil microbes, and suggested the unsolved problems and possible future research direction.