The continuous culture of anaerobic bacteria.

Abstract

Surmmary Modifications to an anaerobic continuous culture apparatus to allow pH control, and pH and Eh measurements, are described. Two anaerobic rumen bacteria were grown under different conditions, but as carbohydrate-limited cultures. The effects of growth rate, pH value and Eh value on yields of bacteria, enzyme activities and fermentation products are described. Optimum bacterial yields per mole of substrate fermented and per mole of ATP presumably formed in the fermentation were variable with the particular bacterium and the substrate, and were high for hexose fermentations. Yields of bacteria varied with growth rate, being lowest at low growth rates. Fermentation products also varied with growth rate and the pH value of the culture in some cases, as did the production of enzymes. Maximum growth rates calculated from batch cultures were in agreement with those found in the continuous cultures.