Developmental block in citric acid cycle mutants of Bacillus subtilis.

Mutants deficient in different enzymes of the citric acid cycle can be subdivided into two groups according to the frequency at which they produce heat-resistant spores in nutrient sporulation medium. However, the majority of cells can develop in this medium only to the axial filament stage I of sporulation; aconitase and isocitrate dehydrogenase mutants need the addition of glutamate to reach this stage.