Sodium acetate promotes the production of biomass and intracellular biochemical components by Micractinium reisseri FM1 under batch and fed-batch cultivation

Carbon source supply and feeding mode play an important effect on the growth and metabolite accumulation of microalgae. In order to investigate the role of acetate and feeding way on the growth behavior of microalgae and synthesis of main intracellular biochemical components, the influence of exogenous sodium acetate (NaAc) and feeding mode on the production of biomass, lipids and other cellular composition by Micractinium reisseri FM1 was evaluated under mixotrophic cultivation. The results indicated that compared with the photoautotrophic control, the biomass and lipid production of the alga showed a linear enhancement trend with the increase of NaAc from 1 to 10 g L. When NaAc was 10 g L, biomass and lipid content of M. reisseri FM1 were 10.65-fold and 4.35-fold of the control, respectively. The maximum volumetric productivities of pigment, protein and carbohydrate were obtained at 4 g L NaAc. Compared with batch culture, the fed-batch mode could significantly enhance the productivity of biomass and lipid. Different cultivation modes did not significantly change the composition of fatty acids, but a higher proportion of total saturated fatty acids was obtained when NaAc was supplied in mixotrophic medium. Our findings suggest that NaAc can be used as a cheap and effective carbon source and physiological regulator for high cell density and yield production of M. reisseri FM1 as biorefinery feedstock.