GRACILIS I. COMPARISON OF TWO CULTURE MEDIA
S.O. Lourenco, U.M. Lanfer Marquez, J. Mancini-Filho, E. Barbarino, E. Aidar-1997
Aquaculture, 148: 153-168
Abstract:
The biochemical profile (protein, total amino acids, carbohydrate, lipid, fatty acids, chlorophyll-a and carotenoids) of the microalga Tetraselmis gracilis, in batch cultures, was studied at the logarithmic and the stationary growth phases. Results obtained using Conway medium (CY: N=1176 microM, nitrogen as nitrate; P= 128 microM; N:P=9.2:1) and a commercial medium in its original formulation (CR: N=1212 microM, nitrogen as ammonium; P=211 microM; N:P=5.7:1) and modified (CM: N=1176 microM, nitrogen as ammonium; P=128 microM; N:P=9.2:1) were compared. The concentration of micronutrients were not modified.
The concentration of all substances in the cultures increased with the cultures' age. Protein content was always low in CY. while the carbohydrate, lipid, chlorophyll-a and carotenoid contents increased sharply in this medium. Relative amounts of amino acids neither varied with time nor with composition of the media used. Relative concentrations of polyunsaturated fatty acids were higher in CR and CM media, especially the 18:4 and 20:5 fatty acids. N and P consumption was faster and complete in CY medium, while no difference was found between the commercial media, except for the partial consumption of P in CR.
Results showed that different culture media generate both distinct and variable biochemical profiles in T. gracilis with time, with implications for the feeding of marine herbivores with this microalga.
(Instituto Oceanografico. Universidade de Sao Paulo. Caixa Postal 66149, CEP 05315-970. Sao Paulo - SP. Brazil)
-----------------------------------------------------------------------------------