[Utilization of Nitrogen Compounds by Phototrophic Bacteria]

Phototrophic purple and green bacteria differ by their ability to assimilate nitrogen compounds. Thiocapsa roseopersicina utilizes not only ammonium and nitrates, as a source of nitrogen, but also urea, azoguanine, cytosine and some amino acids. The non-sulphur bacterium Rhodopseudomonas palustris grows at the account of amine nitrogen of a larger number of amino acids than the sulphur bacterium. Chlorobium limicola 1. thiosulfatophilum grows only on media containing urea and methylamines. Formation of amino acids by the studied phototrophic bacterial cultures is related to amination of alpha-ketoglutarate. Purple bacteria possess also the activity of aspartate dehydrogenase.