Growth optimization of algae for biodiesel production

Area of Science:

• Biotechnology
• Renewable Energy
• Algal Cultivation

Background:

• Algae are a promising source for biofuel due to high oil content and rapid biomass generation.
• A key challenge is maximizing oil yield without compromising algal growth rates.
• Two-stage reactor systems offer a potential solution for optimizing both growth and oil production.

Purpose of the Study:

• To determine optimal reactor design parameters for the first stage of a two-stage algal cultivation system.
• To optimize the growth of two specific microalgal strains, Oocystis sp. and Amphora sp., for biofuel production.

Main Methods:

• Growth kinetics were monitored using in vivo fluorescence and correlated with dry mass.
• Experiments were conducted under various temperature and light intensity conditions.
• Light:dark cycles were varied to determine optimal growth parameters.

Main Results:

• Optimal growth temperatures were 25°C for Oocystis sp. and 30°C for Amphora sp.
• Optimal light intensity was 150 μmol m⁻² s⁻¹ for Oocystis sp. and 80 μmol m⁻² s⁻¹ for Amphora sp.
• A 16:08 light:dark cycle promoted the best growth for both strains, yielding doubling rates of 0.333 d⁻¹ for Oocystis sp. and 0.179 d⁻¹ for Amphora sp.

Conclusions:

• Growth rate is more sensitive to light:dark cycles and temperature than light intensity.
• The study identified optimal conditions for Oocystis sp. and Amphora sp. growth, crucial for maximizing biomass feedstock for biofuel.
• Further research should incorporate agitation and CO2 sparging for enhanced productivity.