[Metabolic characteristics of thermophilic microorganisms]

The maximum growth rate of thermophilic bacteria was found in the exponential growth phase during 2 to 3 hours, and the metabolism was aerobic. In the linear growth phase, the substrate (glucose) was metabolized both by the aerobic and anaerobic pathways during the cultivation of the thermophilic bacteria with shaking; this was confirmed by increasing values of the respiratory quotient and by the evolution of volatile acids. The mesophilic bacteria oxidized the substrate by the aerobic pathway under the same conditions of cultivation, both during the exponential and linear growth phases, and had the stable value of the respiratory quotient. The economic coefficient was lower in the thermophilic microorganisms (bacteria and thermotolerant yeasts) than in the mesophilic cultures.