Water Fern Azolla pinnata Extract as a Novel Organic Nutrient Source for the Cultivation of Spirulina Spirulina platensis

Abstract

This study aimed to observe the potentiality of azolla extract as a cost-effective organic medium. An 18-day culture experiment of Spirulina platensis was conducted using various percentages of dried azolla extract (DAE, 10-50%) or boiled azolla extract (BAE, 10-40%) in place of inorganic Kosaric medium (control). Growth, pigmentation, minerals and lipids contents of S. platensis cultured were recorded. Compared with the control, similar results were obtained in biomass concentration and specific growth rate when up to 40% KM was replaced with 40% DAE or 20% BAE. The mineral and lipid contents of S. platensis were unaffected by the replacement of KM with azolla extracts, except that Ca, Zn, and Fe concentrations increased as the replacement amount of KM with DAE and BAE increased. The KM had the highest chlorophyll a content. Similar findings were observed for chlorophyll a of the S. platensis in DAE40 and BAE20. It was concluded that KM could be partially replaced with DAE or BAE as the novel organic media for S. platensis cultivation, where DAE is better than BAE.