Reduction of N2 by complementary functioning of two components from nitrogen-fixing bacteria.

Asymbiotic nitrogen fixation is a common property of a dissimilar group of microorganisms ranging from obligate anaerobes through the facultatives to the obligate aerobes. Representatives are founid in the nutritional groups of the chemoorganotrophs, the photoorganotrophs, and the photolithotrophs, including both bacteria and the blue-green algae. The nitrogenase enzyme complexes from the bacteria have remarkable similarities as demonstrated by the requirement of anaerobiosis, a low-potential electron donor, and adenosine 5'-triphosphate -for the reduction of N2 to ammonia by Clostridium pasteurianumn,I-' Azotobacter vinelandii, Rhodospirillurn rubrum, Klebsiella pneumroniae,j and Bacillus polymyxa.i) Purification of the nitrogenase enzyme complex from C. pasteurianum7,7 A. vinelandiij and B. polyinyxa9 has demonistrated that at least two componenits are necessary for the reduction of nitrogen. This communication reports investigations designed to determine whether a fraction prepared from one organism will function with a fraction from another.