Marine Algal bioethanol research under DBT-RA individual fellowship

Advancing 3G Biofuels: Sustainable Bioethanol from Marine Algae

As part of the DBT-Research Associateship (DBT-RA) Programme, a two-year independent project was conducted at TERI under the guidance of Dr. Sanjukta Subudhi, Associate Director, Microbial Biofuels and Biochemicals (MBB) Area. This initiative marked TERI’s inaugural engagement under the DBT-RA programme.

The project focused on the potential of third-generation (3G) feedstock—specifically deoiled marine algae (Dunaliella salina) biomass—for sustainable bioethanol production. This work supports India’s strategic transition toward advanced biofuels and diversified bio-based solutions.

From Cultivation to Recovery

The D. salina biomass was cultivated and harvested at TERI’s 1,00,000-litre algal facility in Navi Mumbai (Airoli). The project encompassed a comprehensive lab-scale process:

• Pretreatment & Saccharification: Strategies were optimized using low-cost commercial and native microbial enzymes to maximize sugar release from the algal biomass.
• Fermentation: A native yeast isolate, Candida neerlandica (isolated and identified in-house at TERI), was utilized to convert the recovered sugars into ethanol.
• Downstream Processing: Ethanol recovery was successfully achieved through distillation-based methods.

Adaptive Research & Key Outcomes

While the initial scope included recombinant strain development, the project strategically pivoted to prioritize process scalability and yeast fermentation optimization, ensuring the model's practical viability.

Key Achievements:

• 3G Bioethanol Demonstration: Successfully demonstrated efficient bioethanol production from deoiled D. salina marine algae biomass.
• Optimized Workflows: Achieved critical milestones in pretreatment, sugar recovery, and fermentation, laying a robust foundation for future industrial scale-up.
• Biochemical Insights: Conducted in-depth analyses of algal biochemical composition and performed preliminary experiments on the circular utilization of bioethanol.

Impact and Future Directions

This project reinforces TERI’s commitment to promoting 3G biofuels using non-food biomass sources. The findings provide a vital baseline for future research into enzymatic efficiency enhancement, recombinant strain development, and the integration of algae into multi-product biorefinery models.