EFFECT OF DURATION OF HEATING, l -ALANINE AND SPORE CONCENTRATION ON THE OXIDATION OF GLUCOSE BY SPORES OF BACILLUS CEREUS VAR. TERMINALIS

Abstract

Aged spores of B. terminalis when heat shocked 60-90 minutes at 65[degree]C oxidize glucose in the absence of any detectable germination. Fresh spores, whose glucose oxidation cannot be activated by heat alone, simulate the aged spores when heat shocked in the presence of small amounts of L-alanine. Some of the spores germinate if alanine is added after heat shock. Parafluorophenylalanine inhibits the action of alanine if added before heat shock. The alanine can be washed out after heat shock without any significant decrease in activity. The degree of enzyme activation is a function of the duration of heating, the concentration of L-alanine and the strength of the spore suspension. A relatively dilute, activated spore suspension shows no significant decrease in activity following a second heat shock, while a denser suspension of activated spores loses all its activity. However, the activity is regained almost quantitatively if more alanine is added before the second heat shock. In aged spores activated by heat alone the first time, a longer second heat shock is required even in the presence of added alanine. Enzymes of the activated spores are thus sensitive to heat and more enzymes are activated during the second heat shock. Small amounts of alanine are detected in the washings from aged spores and it is likely that alanine is the agent responsible for the activation of these enzymes. Partial release of dipic-olinic acid of the spores occurs whenever heat shock is accompanied by enzyme activation.