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

Cell division in cultures of the Emerson strain of Chlorellavulgaris is markedly inhibited following inoculation into aglucose medium under conditions which are sub-optimal for autotrophicgrowth. Dry-weight accumulation is not inhibited and the resultis the production of cells considerably larger than those occurringin a glucose-free medium. The more closely the conditions ofculture approach those which are saturating for autotrophicgrowth, the less pronounced is the glucose effect. Evidenceis presented which suggests that the heterotrophic utilizationof glucose may be the dominant form of nutrition during theglucose-induced inhibition of cell division. It is suggestedthat the difference in response to glucose recorded under variousconditions of culture may be a reflection of the extent of glucosesuppression of photosynthesis under the various conditions.The possibility is discussed that the light requirement forcell division shown by this strain may be linked with photosynthesis.