Growth of the cryptophyte microalga <i>Rhodomonas salina</i> (Wislouch) D. R. A. Hill & R. Wetherbee, 1989 under different cultivation conditions
Temperature and irradiance effect was studied on the specific growth rate and biomass accumulation of the cryptophyte alga <i>Rhodomonas salina</i>. Optimal conditions for its cultivation were determined allowing to obtain the maximum biomass. <i>R. salina</i> was cultivated on the Conway medium (in our own modification) at a temperature of (20 ± 1), (24 ± 1), and (28 ± 1) °C and irradiance of 13, 67, 135, and 202 μmol photons·m⁻²·s⁻¹. As shown, an increase in temperature up to above-optimal values resulted in a decrease of the microalga growth rate and biomass. For <i>R. salina</i>, there were no significant differences in growth rates at irradiance of 135 and 202 μmol photons·m⁻²·s⁻¹ (μ values were of (0.69 ± 0.04) and (0.64 ± 0.02) day⁻¹, respectively). The microalga growth slowed down at low irradiance (13 μmol photons·m⁻²·s⁻¹) (μ value was of (0.33 ± 0.03) day⁻¹). The maximum biomass [(3.74 ± 0.28) g·L⁻¹] was obtained at the optimal temperature [(24 ± 1) °C] and irradiance of 135 μmol photons·m⁻²·s⁻¹. Under optimal cultivation conditions, maximum accumulation of proteins was registered at the exponential growth phase (29 %), and maximum accumulation of lipids was recorded at the stationary phase (41 %).