Growth and metabolites of Chlorella sorokiniana regulated by sodium acetate

Abstract:

[Background] As one of the unicellular green algae, Chlorella sp. can accumulate a variety of value-added metabolites under different culture conditions. These metabolites could be used as a good feedstock to produce cosmetics, foods, health products, medicines, etc. However, their large-scale industrial production is restricted because of low productivity of metabolites in the algal cells and the difficulty of separating them by economically viable methods. [Objectives] To study the effects of sodium acetate on biomass production of Chlorella sorokiniana, and to analyze its regulatory role in the production of algal metabolites. [Methods] Different concentrations of sodium acetate (1.0, 2.0, 3.0, 4.0 and 5.0 g/L) were added to the cultures of C. sorokiniana. Growth and metabolites of this alga were determined during algae cultivation to study the regulatory role of sodium acetate. [Results] Biomass concentration of C. sorokiniana was 5.2 times higher than that in the controls, when this alga grew in the cultures with 3.0 g/L sodium acetate. Although no obvious changes in contents of proteins were observed, contents of lipids and carotenoids were 2.4 and 1.2 times greater than that in the controls, respectively, when the alga grew in the cultures with 3.0 g/L sodium acetate. In addition, contents of polysaccharides and chlorophyll a decreased, which were only 54.6% and 54.4% of that in the controls, respectively. [Conclusion] Sodium acetate not only affected the growth of C. sorokiniana, but also regulated its metabolic process. These results would provide theoretical basis and technical data for further exploring the regulatory role of sodium acetate in growth and metabolic process of C. sorokiniana.

Key words:sodium acetate;Chlorella sorokiniana;growth;chlorophyll;protein;polysaccharide