Studies on bioflocculant exopolysaccharides (EPS) produced by Anabaena sp. and its application as bioflocculant for low cost harvesting of Chlorella sp.

Abstract

Microalgae harvesting is critical to remove water from algal growth media with solid-liquid separation. Bioflocculation has the same principle as flocculation. Using solid-liquid separation, microalgae harvesting removes moisture from the algal growth substrate. The same idea underlies flocculation and bioflocculation. Using fungal and bacterial bioflocculants requires a special medium that is different from the microalgae medium, that fungi and bacteria can contaminate microalgae, so it is not recommended to be used as a bioflocculant agent. Microalgae Anabaena sp. was chosen in this study as a bioflocculant agent since it can produce exopolysaccharides (EPSs). Dissolved proteins and carbohydrates make up EPSs. This investigation looked into employing Anabaena species to extract Chlorella species. The harvest day was used to measure the parameters. A spectrophotometer was used to measure the precipitation percentages. Bligh and Dyer's methods were used to measure lipid contents. The phenol-sulfate was used to perform carbohydrates. Bradford method was used to quantify proteins. The ratio of 1:1.25 was determined to have the best proportion of flocculation and carbohydrate content ( Chlorella sp. : Anabaena sp.). The ratio of 1:1 was determined to have the maximum cell lipid and protein content ( Chlorella sp.: Anabaena sp.). The application of this study will be beneficial to design effective methods for harvesting microalgae using biological materials such as other microalgae.