Isolation of freshwater and marine indigenous microalgae species from Terengganu water bodies for potential uses as live feeds in aquaculture industry

Abstract

Microalgae are considered as a promising resource for high-value substances. In this study, indigenous microalgae were isolated from various habitats and the optimum growth parameters for high lipid production were determined. Species identification was done by using universal 18S rDNA. Water quality was recorded during the sampling to determine the basic physical-chemical parameters for the growth studies. The screening for microalgae growth was done using plate reader with a focus on lipid-rich isolates by Nile Red fluorescent dye at different growth phase for 15 days. Results showed that ten microalgae species have been successfully cultivated from Terengganu water bodies. Analysis from genus Chlorella showed five isolates (TRG1-A01, TRG1-C01, TRG2-E01, TRG5-A01, and TRG3-B01) were clustered together, while two isolates (TRG2-1, TRG3-B01) from the genus Nannochloropsis were N. oceania. Another two isolates (TRG1-D01, TRG-E01) were closely clustered with Desmodesmus subspicatus while TRG4-C01 was clustered with Dicloster aquatus. The strain TRG2-A01 showed the highest fluorescent intensity indicating it's potential to produce the highest intracellular lipid content. Thus from this study, we can identify which environmental conditions contribute to the most favourable conditions for algal growth to maximize lipid production which later could be used as live feeds in aquaculture industry.