Synthesis of glutamate in Aerobacter aerogenes by a hitherto unknown route

In order to grow in a simple salts medium in which ammonia provides the sole source of nitrogen, micro-organisms must possess some mechanism for the synthesis of amino acids from ammonia and intermediary metabolites. In many bacteria this requirement is fulfilled by the enzyme glutamate dehydrogenase (EC 1.4.1.4), which reductively aminates 2-oxoglutarate to glutamate. In other bacteria (particularly in some species of Bacillus) analogous amino acid dehydrogenases (e.g. alanine dehydrogenase and leucine dehydrogenase) func- tionally replace glutamate dehydrogenase and glutamate is then formed by an aminotransferase reaction.