The potential of Chlorella vulgaris (Chlorophyta, Trebouxiophyceae) to reduce carbon dioxide emissions: statistical optimization of carbon dioxide utilization and algal biomass production

Global warming is considered one of the most serious and pressing environmental issues in the world, which opens possibilities for finding decisive and effective strategies to reduce the accumulation of gases, especially carbon dioxide emissions. Fortunately, algae mainly depend on CO2 gas in the photosynthesis process, and the algal biomass produced can be converted into useful and economically valuable materials. The coccoid green microalga Chlorella vulgaris is one of the best algal species that can be used as a model in this biotechnology. In the present study, factors affecting the CO2 consumption, including temperature, pH, light intensity (LI), carbon source availability, and CO2 supply were statistically optimized using the response surface methodology. The C. vulgaris growth was measured by cell count and dry weight, as well as estimating CO2 content in the culturing medium. The results revealed that the highest algal growth and gas consumption rates were optimized in CO2-aerated Z-medium and in the presence of a carbon source (Na2CO3) at 38 degrees C, alkaline pH 8.6, and LI 5654 lux. This study sheds the light on the significant potential of microalgae to reduce carbon dioxide emissions as an eco-friendly and renewable strategy for resolving the environmental pollution problems.