CARBOHYDRATE NUTRITION OFCHLORELLA VULGARIS

Abstract

A substrain of the Pratt–Trelease strain of Chlorella vulgaris was grown at 30 °C. in light (200 ft-c.) and in darkness, on Emerson's medium enriched with various carbohydrates and related compounds in 1% concentration. D-glucose, D-fructose, D-galactose, and β-glucosides such as aesculin, cellobiose, lactose, and methyl-β-D-glucoside, are all good sources of carbon and energy for growth in darkness. Alpha glucosides such as sucrose, maltose, and methyl-α-D-glucoside are poor substrates as are also D-mannose, L-mannose, L-galactose, the pentoses, sugar acids, sugar alcohols, and polysaccharides. Illumination stimulates growth in the presence of D-glucose, D-fructose, and D-galactose more than in the presence of the β-glucosides. With methyl-β-D-glucoside better growth is obtained in darkness than in light. The optimum temperature for growth of the organism is near 35 °C. in the media used. Basal media containing nitrate nitrogen allow better utilization of sugars than those containing ammonia nitrogen. Most of the glucose utilized is converted to cellular material.