Determining the optimal culture conditions for algae growth is one way of increasing its products,
such as carbohydrates, which may assume an important role in increasing the amount of algaeyielded ethanol. The present study was conducted to determine the effects of light-dark photoperiod
(12-12h, 16-8h, 20-4h) and temperature (25 ?C, 29 ?C, and 33 ?C) on growth rate and sugar content
of Parachlorella kessleri Microalgae. In this study, microalgae were cultured in nine different
treatments (each with three replications) of specified photoperiod and temperature conditions.
Data analysis showed that temperature has no significant effects on the growth factor (p?0.05);
however significant effect of photoperiod was observed on the growth factor (p? 0.05). In addition,
the effect of interaction of photoperiod and temperature on this factor was not significant (p?0.05).
In conclusion, the optimum culture conditions obtained in the photoperiod of 12-12h (light-dark)
and temperature of 25 ? C.