State Research Center — Institute of Highly Pure Biopreparations, St. Petersburg, Russia
The qualitative and quantitative composition of E.coli M-17 metabolites was determined by amino acid analysis and 1H-NMR spectroscopy. According to the character of their individual action on the growth of the producer strain, all substances were tentatively subdivided into 3 classes: growth stimulators (their activity decreased in the row: succinate > glutamate > methionine > acetate ³ lysine), inhibitors (alanine, aspartate, histidine, formiate, cysteine) and compositions having no pronounced individual activity (all others). Still the highest degree of growth stimulation was ensured by the combination of the identified exometabolites, including the compositions of all 3 classes. An important role in the regulation of growth was supposed to belong to acetate which stimulated the growth of the culture at low concentrations and inhibited it at high concentrations. Low concentrations of acetate increased the activity of other growth stimulators and leveled (or even changed in the opposite direction) the action of inhibitors.
Zh. Mikrobiol. (Moscow), 2003, P. 20—25