Influence of the glucose input concentration on the kinetics of metabolic production by Klebsiella aerogenes NCTC 418: growing in chemostat culture in potassium- or ammonia-limited environments.
With chemostat cultures of Klebsiella aerogenes growing at a fixed dilution rate, initially under conditions of glucose-limitation, transition to either potassium-limitation or ammonia-limitation was found not to be a steep step function. A wide range of intermediate steady states could be established in which neither substrate was present in excess of the growth requirement. As the molar ratio of glucose: K+ in the feed medium was progressively increased, the additional glucose carbon was first converted solely to CO2. Thereafter, when the molar ratio exceeded 45, acetate, and then pyruvate and 2-ketogluconate were excreted at increasing rates. In contrast, transition to ammonia-limitation provoked an early excretion of 2-oxoglutarate and 2-ketogluconate, followed (at higher glucose input concentrations) by acetate and pyruvate. These patterns of product excretion are considered in relation to the specific nature of the growth-limitation, to probable changes in the energy charge and redox balance within the growing cells, and to the accompanying modulation of tricarboxylic acid-cycle activity.
D000085:Acetates / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism*; D002245:Carbon Dioxide / Q000096:biosynthesis; D005942:Gluconates / Q000096:biosynthesis; D005947:Glucose / Q000378:metabolism*; D007656:Ketoglutaric Acids / Q000096:biosynthesis; D007711:Klebsiella pneumoniae / Q000254:growth & development / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D011773:Pyruvates / Q000096:biosynthesis
D000085:Acetates; D005942:Gluconates; D007656:Ketoglutaric Acids; D011773:Pyruvates; D002245:Carbon Dioxide; D000641:Ammonia; D005947:Glucose; D011188:Potassium