Investigation of the microalgae diversity and physico-chemistry of Ozi Lake as preliminary steps in bioprospecting for bioactive molecules against SARS-COV-2

Abstract

Benefits derivable from ecosystems (ecosystems services) have elicited various research interests, traversing different disciplines, including biomedical and medical. We investigated Ozi Lake for microalgae whose metabolites have been reported to act against SARS-CoV-2. Water samples were collected two times per month for twelve months, at fortnightly intervals. The microalgae in the water samples were studied using light microscopes, and identified with microalgae photographs contained in standard textbooks, journal articles and microalgae database websites; the physico-chemical parameters were analysed after the methods of American Public Health Association. One hundred and eighty-seven species of microalgae were recorded, of which three genera – Chlorella, Euglena, and Spirulina – have been reported to be effective against COVID-19. The microalgae species and abundance data showed temporal and spatial variations; Chlorella had one species, with recorded populations of 9850 cells; Euglena had 34 species, with recorded populations of 23945 individuals; and Spirulina had one species with recorded populations of 66 individuals. Descriptive statistics, ANOVA, Pearson correlations and t-test analyses were carried out against the phytoplankton and physico-chemical parameters. Chlorella, Euglena and total phytoplankton (Chlorella sp.+ Euglena spp. +Spirulina sp.) showed wider populations variation between months of investigation than across locations. Seasonal variations in the abundance of the microalgae showed that Chlorella, Euglena and total phytoplankton were higher during dry season months than rainy season.  Euglena spp. and total phytoplankton had significant correlations with pH, TDS, COD, nitrate, Fe, DO, and rainfall. Ozi Lake is veritable harbour and breeding grounds for auspicious microalgae species; including those reported to have shown promising use against COVID-19 pandemic.