Investigation of the value-added potential of some selected freshwater cyanobacteria

Ever growing population and environmental degradation lead to a rapid deterioration of global health, causing malnutrition and Ultra Violet radiation-induced skin damages to be more prevalent. It is critical to address these health issues quickly and sustainably. Compared to natural botanicals, cyanobacteria could be more promising due to their superior photosynthetic capabilities, rapid growth, low space and simple nutrients requirements, low capital investment, and zero environmental pollution. Therefore, this study explores the value-added potential of freshwater cyanobacteria in addressing the above health issues sustainably. Eight cyanobacteria strains, isolated from freshwater reservoirs in the dry zone of Sri Lanka were analyzed for total carbohydrate, protein, macro and micro minerals using Dubois' method, Lowry method, and Inductively Coupled Plasma Optical Emission Spectrometry. Mansur equation was applied to determine the Sun Protection Factor (SPF). Total carbohydrate and protein contents were in the range of 7.08 +/- 0.32% - 53.08 +/- 0.32% and 15.27 +/- 0.90% - 49.77 +/- 9.62%, respectively. Oscillatoriales had the highest total carbohydrate content (53.08 +/- 0.32%), higher than the carbohydrate content of other previously reported Oscillatoria species. Calcium and iron were the most abundant macro and micro minerals, respectively. Oscillatoriales recorded the highest SPF (1.57 +/- 0.002), whereas all the other strains had considerably greater or similar SPFs compared to other previously reported herbal extracts. Cyanobacteria with rich nutrition profiles and high SPF values may thus represent interesting alternatives for offering sustainable and ecofriendly solutions to significant health challenges associated with population growth.