Bacteria biological nitrogen fixation

Biological nitrogen fixation Nitrogen fixation, the conversion of Nj to fixed forms, such as ammonium, by the actions of bacteria. 

Biological nitrogen fixation is well known to be associated with the blue-green algae and bacteria in marsh systems however, its quantitative contribution to the nitrogen balance or the reduction in yield it entails are not clear from available data. Supply of nutrients must be considered as a major, though not insurmountable, problem in the optimal management of marsh systems. 

Many bacteria perform services we find useful and even necessary, although we rarely take note of them. Some bacteria participate in the decomposition of dead plants and animals and so help recycle chemicals that are otherwise locked away from the living world. Some are sources of antibiotics that have revolutionized the treatment of infectious disease in the past fifty years. Others are responsible for nitrogen fixation, converting relatively inert atmospheric nitrogen into biologically useful ammonia—a conversion that is not simple in the chemical laboratory. Still other bacteria are indispensable in the world s kitchens, for without them there would be no cheese or yogurt, nor any of hundreds of other traditional milk products. We could not enjoy pickles or sauerkraut, and... 

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