Research Progress on Marine Microbial Nitrogen Fixation

This review primarily introduced the diversity of diazotrophs and nitrogen-fixing gene and the main developments in molecular ecological studies of marine microbial nitrogen fixation.A lot of uncultured di- azotrophs and newnifH genes were discovered with molecular ecological methods in recent years.The studies suggested that diazotrophs in deep sea played an important role in export new nitrogen to surroundings.The current researches about marine diazotrophs revealed the nitrogen-fixing activity existed even in the natural en- vironment with high concentration of NH+ 4 and nitrogen fixation was influenced by the pollution factors.Those discoveries provided new ideas in the field of studying marine microbial nitrogen fixation.