REGULATION OF AMMONIUM ASSIMILATION BY CLOSTRIDIUM-ACETOBUTYLICUM

Assimilation of ammonium by the obligate anaerobic bacterium Clostridium acetobutylicum was accomplished by the pathway: Glutamine synthetase/glutamate synthase. C. acetobutylicum also contained an asparagine synthetase, but no glutamate dehydrogenase activity was detected. The glutamine synthetase was partially repressed by addition of large amounts of ammonium chloride and/or casaminoacids to the medium, while the biosynthesis of the other enzymes was not regulated by the extracellular concentration of ammonium.