An update on valorising dark fermentation effluent through microbial lipid synthesis

Area of Science:

• Biotechnology and Bioeconomy
• Renewable Energy
• Sustainable Biorefining

Background:

• The bioeconomy necessitates efficient biomass transformation into valuable products.
• Dark fermentation effluent, rich in short-chain carboxylic acids, is a promising feedstock for microbial lipid production.
• This effluent supports circular biorefinery strategies using biogenic waste streams.

Purpose of the Study:

• To review microbial lipid production from dark fermentation effluent.
• To compare the potential of oleaginous yeasts, marine protists, and microalgae.
• To identify strategies for enhancing lipid yield and process integration.

Main Methods:

• Literature review focusing on microbial lipid production from dark fermentation effluent.
• Comparative analysis of oleaginous yeasts, marine protists, and microalgae.
• Assessment of two-stage fermentation strategies (dissolved oxygen or pH-auxostat modes).

Main Results:

• Yeasts and protists demonstrate superior performance over microalgae in lipid production from dark fermentation effluent.
• Advantages include faster growth rates, higher lipid yields, and better adaptability.
• Two-stage operations enable independent optimization of biomass production and lipid accumulation.

Conclusions:

• Microbial lipid production from dark fermentation effluent is a viable sustainable strategy.
• Yeasts and protists are more suitable than microalgae for this application.
• Further research is needed to address challenges in solid-liquid separation, sterilization, and process integration.