[Asparaginase and glutaminase activity in Pseudomonas fluorescens in continuous cultivation]

The cells of Pseudomonas fluorescens AG contain two inducable asparaginase enzymes: one of them hydrolyzes only L-asparagine (asparaginase A), the other--L-asparagine, L-glutamine, and D-asparagine (asparaginase AG). In the conditions of continuous cultivation of the bacteria, aspartic and glutamic acids induce the formation of these enzymes only when the amino acids were used simultaneously as a growth-limiting factor and as a sole source of carbon and nitrogen. Both enzymes are not induced in the conditions when the growth is limited by the nitrogen of these amino acids. When the growth was limited by carbon, asparagine, aspartic and glutamic acids induce asparaginase AG more than asparaginase A. Asparagine and glutamine are better inductors than the corresponding amino acids. The activity of asparaginase and glutaminase increases with the specific growth rate of the culture. The induced synthesis of both amidases, after prolonged growth of the culture on a defined medium with glycerol, is inhibited by glycerol but not by glucose. The results are discussed from the viewpoint of regulation of amidases in these bacterial cells.