The Effect of Glucose on Cell Division in Chlorella vulgaris, Beijerinck (Emerson Strain)

Abstract

Cell division in cultures of the Emerson strain of Chlorella vulgaris is markedly inhibited following inoculation into a glucose medium under conditions which are sub-optimal for autotrophic growth. Dry-weight accumulation is not inhibited and the result is the production of cells considerably larger than those occurring in a glucose-free medium. The more closely the conditions of culture approach those which are saturating for autotrophic growth, the less pronounced is the glucose effect. Evidence is presented which suggests that the heterotrophic utilization of glucose may be the dominant form of nutrition during the glucose-induced inhibition of cell division. It is suggested that the difference in response to glucose recorded under various conditions of culture may be a reflection of the extent of glucose suppression of photosynthesis under the various conditions. The possibility is discussed that the light requirement for cell division shown by this strain may be linked with photosynthesis.