INFLUENCE OF SUBSIDIARY ENERGY ON GROWTH OF DUNALIELLA-VIRIDIS TEODORESCO - THE ROLE OF EXTRA ENERGY IN ALGAL GROWTH

An account is given of the influence of different levels of mechanical energy, in the form of bubbling, on the growth of the microalga Dunal iella viridis when other variables (e.g. temperature, nutrient supply, photon fluence) do not change. The extra energy was quantified accura tely through the application of the classical equations of mass and en ergy conservation providing a method for the calculation of the energy efficiency of primary production related to the total energy input, i n which photon fluence was found to be the most important. The specifi c growth rate (mu) of the population vs the input of auxiliary energy fits to a second order polynomial function with a maximum growth rate at 0.63 W m-2. The increase of maximal cell density follows a hyperbol ic saturation kinetics, with saturation at those same values of extra energy. Both primary production and the efficiency of energy transform ation in D. viridis vs the variation of total energy input fit to hype rbolic functions, reaching a maximum efficiency for primary production of 0.85%.