Efecto del nitrato en el crecimiento y producción de astaxantina en la microalga Haematococcus pluvialis (Chlorophyta: Chlamydomonadales) cultivada en condiciones de laboratorio

Abstract

The effect of NaNO3 on the growth and production of astaxanthin was evaluated in the Haematococcus pluvialis microalgae, cultivated under laboratory conditions. The species was inoculated in modified Bold culture medium, establishing different concentrations as tests: 0.45, 0.60 and 1.0 g / L of NaNO3 in the culture medium, in triplicate, and a control (unmodified medium). All cultures were maintained at a constant temperature of 25 ± 1 ° C, daily shaking and photoperiod (12:12). Cell counts were performed every 48 hours, until the stationary phase was reached; then, the variables of cell density, growth rate and doubling time were estimated; in addition, the content of astaxanthin in H. pluvialis produced under stress conditions in the culture medium was determined and the growth and production of astaxanthin was compared in each of the treatments. The results showed that the concentration of NaNO3 in the culture medium did not significantly inhibit the population growth of H. pluvialis, except during the 48 hours and 240 hours. Growth kinetic parameters indicated slight delays in the specific growth rate and doubling time, showing differences in both variables at 48 hours and at the end of the test. On the other hand, the unmodified Bold Medium (0.85 g / L) presented the highest concentration of astaxanthin compared to the other treatments with a value of (3,335 mg.g1 ), when comparing the density and production of astaxanthin among the treatments, it was obtained that the control treatment presented a good performance in both variables showing a cell density of (222x104 cell / mL) and the highest content of astaxanthin (3,335 mg.g1 ).