Production of bioethanol from microalgae biomass (Arthrospira Platensis)

Abstract

Amidst growing interest in renewable energy sources to address climate change challenges and fossil fuel dependency, this study aimed to evaluate the potential of using the microalga Arthrospira platensis (Spirulina) biomass as a sustainable feedstock for bioethanol production. An integrated methodology combining computational analysis (In-silico) and practical experiments (In-vitro) was adopted. The computational analysis involved molecular docking to assess the interaction between the glucoamylase enzyme from the fungus Aspergillus niger and the maltose substrate. Results showed a strong and thermodynamically favorable binding affinity (ΔG = -7.0 kcal/mol), identifying hydrogen bonds and key amino acids (ARG596, GLU597, THR614, ARG616) responsible for complex stability. Practical experiments included enzymatic hydrolysis of Spirulina biomass using crude A. Niger enzymes, followed by fermentation using Saccharomyces cerevisiae yeast. This process yielded an encouraging bioethanol yield of 62.5%. Combustion testing of the produced bioethanol confirmed good combustion efficiency, although slight mineral impurities were observed, indicating a need for optimizing purification steps. The findings of this study demonstrate the scientific and practical feasibility of using Spirulina platensis and A. Niger enzymes for bioethanol production, confirming the potential of microalgae as a promising source for third-generation biofuels, thereby opening prospects for developing more sustainable energy technologies.