- Volume 70, Issue 2, 1972

The spores of Clostridium tetani will germinate aerobically and anaerobically in complex media such as heart infusion broth or tryptone with yeast extract at 37° and pH 7·5. A synthetic medium as effective as heart infusion broth for germination under both aerobic and anaerobic conditions consists of 1 mm-methionine, 100 mm-lactate, 82 μ m-nicotinamide, 280 mm-Na+ in 40 mm-phosphate buffer, pH 7·5. Anaerobic germination would take place in either methionine with Na+ or lactate and nicotinamide with Na+, but all the germinants were essential aerobically. Heat activation did not occur and thioglycollate increased the rate of germination.

Medium composition influenced the synthesis and breakdown of glutamic acid and alanine by Bacillus licheniformis examined in a chemostat. With ammonia in growth-limiting quantities as the sole nitrogen source, glutamate was synthesized from 2-oxoglutarate via glutamine synthetase and glutamine amide 2-oxoglutarate amino transferase (NADP; oxidoreductase), and alanine was formed from glutamate and pyruvate by transamination. With excess nitrogen, as either alanine or glutamate, a carbon-limited culture synthesized respectively NAD-linked alanine dehydrogenase or NADP-linked glutamate dehydrogenase, and the latter two enzymes performed only a catabolic role. If, however, nitrogen was supplied as alanine or glutamate to a nitrogen-limited culture, then synthesis of alanine dehydrogenase and glutamate dehydrogenase was repressed. Correlations were drawn between the nature of the growth environment, the composition of the amino acid pools and the synthesis of the above mentioned enzymes in B. licheniformis.

The ATP pool in Selenomonas ruminantium growing in continuous culture under carbohydrate-limited conditions was low (averaging 2·3 nmoles/mg dry wt bacteria) and appeared independent of growth rate over the range of optimum growth. The high maximum growth yield (Y gluc62) previously found for another strain of sele-nomonad was confirmed and growth on glucose plus pyruvate gave a calculated value for Y pyr of about 21. A tentative scheme is suggested for production of ATP from electron-transfer reactions which would make the value for Y ATP for high growth-yield rumen anaerobic bacteria nearer to the accepted value of 10 than the values found using previously suggested modes of ATP formation.