Respiratory Behavior of the Propionic Acid Bacteria

Abstract

Redox potential data obtained with resting cells of propionic acid bacteria, using succinic, fumaric, or malic acids as hydrogen donators, with various hydrogen acceptors show the following results. Succinic acid acts as a donator to methylene blue, NaNO3, and o-chlorophenol-indophenol. Fumaric acid may donate hydrogen to a less degree to methylene blue and o-chlorophenol-indophenol, while malic acid shows only a slight donation to these acceptors. Respiration experiments using the Barcroft-Warburg technique show marked O2-uptake with buffered suspensions of propionic acid bacteria when succinic, lactic, and pyruvic acids are used as substrates; much less with malic and fumaric acids. In an atmosphere of nitrogen, CO2 is evolved in relatively large quantities from succinic, lactic, and pyruvic acids, and in smaller amounts from fumaric and malic acids. From these results it is concluded that the conversion of succinic acid to propionic acid proposed by Wood, Stone and Werkman1 probably takes place by dire...