Effects of alpha- and beta-D-glucose on germination of spores of Bacillus megaterium QM B1551

Anomeric specificity of glucose effect on cAMP, fructose 1,6-bisphosphatase, and trehalase in yeast

The addition of beta-D-glucose (final concentration, 50 mM) to a cell suspension of Saccharomyces cerevisiae in stationary phase caused a rapid 4-fold increase in the concentration of cAMP, while a 2-fold increase of cAMP was observed by the addition of alpha-D-glucose. beta -D-Glucose was also more effective than alpha-D-glucose in the inactivation of fructose 1,6-bisphosphatase and the activation of trehalase. These results, taken together with the previous report that alpha-D-glucose is transported more rapidly than beta-D-glucose in Saccharomyces cerevisiae, do not support the view currently proposed by some investigators that cotransport of D-glucose with protons causes the depolarization of the cell membrane, resulting in the activation of adenylate cyclase. The present data, however, provides supporting evidence for the view that cAMP-dependent protein kinase is implicated in the inactivation of fructose 1,6-bisphosphatase and the activation of trehalase.

Relation between D-glucose and L- and D-alanine in the initiation of germination of Bacillus subtilis spore

The rate of L-alanine-initiated germination of Bacillus subtilis spore was measured by both loss of heat resistance and loss of turbidity, and the effect of glucose on the germination response to a wide range of concentrations of the germinant was analyzed in the presence and absence of D-alanine, an inhibitor. Glucose stimulated L-alanine germination by means of a cooperative effect: glucose increased the affinity of L-alanine by about 3-fold and the rate of germination by about 1.3-fold. However, glucose had little effect on the binding affinity of D-alanine. The apparent binding constant of L-alanine to the spore, which was determined by the next measurable event in the trigger reaction, was 1.2 X 10(-5), that of D-alanine was 6 X 10(-6), and that of glucose was 5 X 10(-5). The relation between the binding site for glucose and those for L- and D-alanine on the spore is discussed. Effect of glucose analogs was also examined.

Different effects of D-glucose anomers for respiration of bacterial germinated spores

Effects of alpha- or beta-D-glucose on the respiration of germinated spores (only germinated spores not including swollen spores and elongated spores) of Bacillus subtilis and B. megaterium were studied. In our conditions, net amount of oxygen consumed by 10(10) germinated spores of B. subtilis per min after addition of alpha- or beta-D-glucose was 1.6 microgram or 6.6 microgram (beta/alpha = 4.13), while that by B.megaterium was 4.5 microgram of 6.8 microgram (beta/alpha = 1.51), respectively. However, the net amounts of oxygen consumed by 10(10) vegetative cells per min after addition of alpha- or beta-D-glucose were identical, for B.subtillis in both cases 443.0 microgram and for B.megaterium in both cases 604.4 microgram.