Ethanol effect on batch and fed-batch Arthrospira platensis growth

Area of Science:

• Biotechnology
• Microbiology
• Algal Biotechnology

Background:

• Arthrospira platensis is a cyanobacterium with significant nutritional and industrial potential.
• Efficiently utilizing alternative carbon sources is crucial for optimizing algal cultivation.
• Ethanol offers a readily available and potentially cost-effective carbon source.

Purpose of the Study:

• To investigate the feasibility of using ethanol as a sole carbon and energy source for Arthrospira platensis growth.
• To compare the efficacy of batch and fed-batch cultivation strategies for ethanol utilization.
• To determine optimal conditions for maximizing Arthrospira platensis biomass concentration using ethanol.

Main Methods:

• Cultivation of Arthrospira platensis using batch and fed-batch processes with varying ethanol concentrations.
• Monitoring of cell concentration (X) and specific growth rate (μ) under different feeding regimes.
• Comparative analysis of growth kinetics between ethanol-supplemented and control cultures.

Main Results:

• Arthrospira platensis demonstrated a marked increase in cell concentration when supplemented with ethanol compared to control cultures.
• The fed-batch process, particularly with a daily ethanol pulse of 38 mg L⁻¹ day⁻¹, yielded the highest cell concentration (2,393 ± 241 mg L⁻¹).
• Specific growth rates were highest in the early exponential phase, with slower decreases observed in the fed-batch process, leading to superior final biomass yields.

Conclusions:

• Ethanol is a viable and effective carbon and energy source for Arthrospira platensis cultivation.
• The fed-batch process is a superior strategy for enhancing Arthrospira platensis biomass production using ethanol.
• This research supports the potential of using industrial byproducts like ethanol for sustainable algal biomass generation.