Which are products of nitrogen fixation

Some bacteria can convert N2 into ammonia by the process termed nitrogen fixation; these bacteria are either free-living or form symbiotic associations with plants or other organisms (e. g. termites, protozoa) other bacteria bring about transformations of ammonia to nitrate, and of nitrate to N2 or other nitrogen gases.-Nitrogen fixation archive. bio. ed. ac. uk/jdeacon/microbes/nitrogen. htm