A Method for Adapting Euglena gracilis to Cassava-Based Substrates for Heterotrophic Cultivation

Area of Science:

• Biotechnology
• Microbiology
• Sustainable Agriculture

Background:

• Cassava by-products are nutrient-rich but underutilized due to variability and contaminants.
• Developing methods for utilizing these by-products is crucial for waste valorization.

Purpose of the Study:

• To present a protocol for adapting Euglena gracilis to cassava-derived substrates.
• To establish a cassava-tolerant algal lineage for heterotrophic cultivation.
• To evaluate the performance of adapted strains across various cassava products.

Main Methods:

• Multistage adaptation of Euglena gracilis cultures to increasing concentrations of autoclaved and non-autoclaved cassava media.
• Exposure to garri concentration gradients (10-50 g/L) to assess tolerance.
• Comparison of adapted lineage with wild-type across five cassava products (garri, pulp, pellets, peels, animal feed).
• Measurement of pH, cyanide levels, and protein content of biomass.

Main Results:

• Successful adaptation of Euglena gracilis to tolerate and grow on cassava-derived substrates.
• Demonstrated growth consistency of the adapted lineage across diverse cassava products.
• Quantified key parameters including pH, cyanide levels, and protein content.

Conclusions:

• The protocol provides a reproducible framework for adapting Euglena gracilis to cassava waste.
• This method facilitates the development of robust algal lineages for cassava bioprocessing and waste valorization.
• Enables sustainable utilization of nutrient-rich cassava by-products.