Metabolism During Asexual Sporulation in Rhizopus arrhizus (Fischer)

Abstract

The metabolism of Rhizopus arrhizus (Fischer) during growth and asexual sporulation was investigated. Aerobic respiration occurred during spore germination but changed to fermentation during the initial stages of growth. During the later stages of growth and sporulation, the respiration again became aerobic. The fermentative phase during the initial growth stage was a result of culture technique. Sporulation was induced by glucose exhaustion. Protein was the major endogenous substrate during sporulation. Lipid reserves decreased, but non-structural carbohydrate reserves remained unchanged. The fermentation acids, over half of which were taken up from the culture medium, were the major exogenous substrate during sporulation. Lactate was identified as one of two fermentation acids produced in significant quantities. On a weight consumed basis, the fermentation acids were the major substrates utilized during sporulation.