Optimizing Growth Conditions and Biomass Accumulation for Chlorella vulgaris of the Western Indian Ocean, Tanzania

Abstract

Microalgae hold significant potential for addressing global challenges such as climate change, food security, and environmental  degradation. However, data on optimal culture conditions for growth and biochemical composition, particularly for microalgae from the  Western Indian Ocean, are limited. This study evaluated the growth and biochemical composition of Chlorella vulgaris isolated from  Tanzanian estuaries. Two experiments were conducted. In the first, C. vulgaris was cultured under high (5.5 ± 3.3 Klux) and low (2.9 ± 1.6 Klux) light intensities, with samples collected for biochemical analysis on days 7 and 14. The second experiment examined the effects of  salinity (5, 10, 15, 20, and 33 g kg⁻¹) on growth under a light intensity of 2.9 ± 1.6 Klux. Optimal growth was observed at 15 g kg⁻¹ salinity  level. Higher light intensities increased crude protein and iron content while lower light favored lipid, carbohydrate, and phosphorus  accumulation. Shorter culture periods (7 days) enhanced protein, lipid, and carbohydrate levels, whereas longer periods (14 days)  increased ash and specific minerals like iron, potassium, and calcium. These findings provide strategies for optimizing C. vulgaris growth  and composition for continually harnessing its potential for addressing global challenges.