Application of mathematical models to the determination optimal glucose concentration and light intensity for mixotrophic culture of Spirulina platensis

Abstract

The effects of initial glucose concentration and light intensity on specific growth rate, phycocyanin concentration and cell dry weight concentration in mixotrophic batch cultivation of Spirulina platensis using both shake flask and fermenter were investigated. Based on experimental results in shake flask culture, a number of mathematical models were constructed, and the optimal initial glucose concentration and the optimal light intensity were calculated to be S(opt) = 2.4471 g liter-1 and L(opt) = 3.8632 klx. Finally, a time-dependent kinetic model for mixotrophic batch cultivation of Spirulina platensis in fermenter was also proposed. This was in good agreement with the experimental results and could be employed to predict the production of biomass and phycocyanin, and the consumption of glucose in fermenter culture.