THE SOLUBLE FRACTION OF SOLANUM-TUBEROSUM ENHANCES GROWTH AND PIGMENTATION OF THE MICROALGA TETRASELMIS-SUECICA UNDER PHOTOHETEROTROPHIC CONDITIONS

The soluble fraction of Solanum tuberosum was utilized in the range 0. 1-6.2 mg dry weight ml(-1) to stimulate photoheterotrophic growth of a xenic cultures of the marine microalga Tetraselmis suecica The concent ration of 5.0 mg ml(-1) produced the highest cell density, 1.4x10(6) c ells ml(-1). This was 3.9 and 3.1 times higher than an autotrophic con trol (0.4x10(6) cells and a photoheterotrophic control (0.5x10(6) cell s ml(-1)). Using 3.7 mg dry weight of the S. tuberosum extract ml(-1), the microalgae reached the highest contents of chlorophyll and carote noids, 8.2 and 4.1 times higher than the autotrophic control. The mark ed enhancement of the photoheterotrophic growth of the microalgae by t he addition of potato extract exceeded the growth stimulation caused b y glucose and yeast extract. It suggests the feasibility of the use of potato biomass for the production of microalgal biomass and pigments. (C) 1997 Elsevier Science Ltd.