We evaluated the kinetic culture characteristics of the microalgae Cyanobium sp. grown in vertical tubular photobioreactor in semicontinuous mode. Cultivation was carried out in vertical tubular photobioreactor for 2 L, in 57 d, at 30 degrees C, 3200 Lux, and 12 h light/dark photoperiod. The maximum specific growth rate was found as 0.127 d(-1), when the culture had blend concentration of 1.0 g L(-1), renewal rate of 50%, and sodium bicarbonate concentration of 1.0 g L(-1). The maximum values of productivity (0.071 g L(-1) d(-1)) and number of cycles (10) were observed in blend concentration of 1.0 g L(-1), renewal rate of 30%, and bicarbonate concentration of 1.0 g L(-1). The results showed the potential of semicontinuous cultivation of Cyanobium sp. in closed tubular bioreactor, combining factors such as blend concentration, renewal rate, and sodium bicarbonate concentration. 2011 Published by Elsevier Ltd.