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Isolation And Culture Of Benthic Microalgae From The Colombian Caribbean Under Different Temperature Conditions
Authors: Alix Barreto Hernández, Luz Adriana Velasco
Number of views: 659
In order to create a collection of marine benthic microalgae from the Colombian Caribbean, some strains were isolated and cultured under different temperature conditions. From periphyton samples of PVC plates placed in the rocky intertidal of Taganga, Santa Marta (Colombia), the type and number of isolated species, as well as the density and relative growth constant (K) of three of the isolated strains were assessed under three different temperatures (20, 25 and 28 °C). Constant conditions of culture medium Guillard F/2 (250 ml), artificial light (1500 lux) and initial values of salinity of 30‰ and pH of 7,0 were maintained. Five benthic microalgae strains were isolated at 20 °C (Cylindrotheca closterium, Komvophoron crissum, Tetraselmis sp. and 2 morphotypes de la familia Bacillariaceae); at 25 and 28 °C, none of the strains was obtained. In the diatom identified as Bacillariaceae diatom morphotype 1, the highest values of cell density (96,3 x 105 cells.ml -1) and K (1,03 div.day-1), were obtained at temperatures of 20 and 25 °C, while it was impossible to obtain their growth at 28 °C. Conversely, in the microalgae Cylindrotheca closterium and Tetraselmis sp. higher density values (2,6 and 7,7 x 105 cells ml-1, respectively ) were obtained in the 25 °C treatment, while the highest values of K occurred at 28 °C (0,64 and 0,60 div.d-1, respectively). This study allowed starting a collection of benthic marine microalgae, as well as to determine the most suitable temperatures for the microalgae isolation (20 °C) and cell production of Bacillariaceae morphotype 1, Cylindrotheca closterium and Tetraselmis sp. (25 °C).