Deciphering role of technical bioprocess parameters for bioethanol production using microalgae.

Area of Science:

• Biotechnology and Bioengineering
• Renewable Energy Sources
• Microalgal Cultivation

Background:

• Microalgae are a promising feedstock for biofuels and bioactive compounds.
• Closteriopsis acicularis offers faster growth and higher biomass accumulation than traditional feedstocks.
• Optimizing cultivation conditions is crucial for maximizing microalgal productivity.

Purpose of the Study:

• To maximize the specific growth rate and biomass productivity of Closteriopsis acicularis.
• To investigate the effects of pH and phosphate concentration on microalgal growth and bioethanol production.
• To optimize autotrophic cultivation of Closteriopsis acicularis for enhanced bioethanol yield.

Main Methods:

• Utilized Central Composite Design (CCD) and Response Surface Methodology (RSM) for optimization.
• Cultivated freshwater green microalgae Closteriopsis acicularis in an autotrophic mode.
• Analyzed biomass elemental composition and Fourier transform infrared (FTIR) spectroscopy.

Main Results:

• Achieved a maximum specific growth rate of 0.342 day⁻¹ and biomass productivity of 0.497 g L⁻¹ day⁻¹.
• Optimal conditions identified as high phosphate concentration (0.115 g L⁻¹) and pH 9 on day 21.
• Optimized biomass showed enhanced carbohydrate content (58%) yielding 14.9 g/L bioethanol.

Conclusions:

• Phosphate concentration and pH significantly influence Closteriopsis acicularis growth and biomass productivity.
• Optimized cultivation parameters lead to enhanced microalgal biomass and bioethanol yield.
• Closteriopsis acicularis is a viable candidate for sustainable bioethanol production.