Catalytic hydrolysis of agar using magnetic nanoparticles: optimization and characterization

Agar is used as a gelling agent that possesses a variety of biological properties; it consists of the polysaccharides agarose and porphyrin. In addition, the monomeric sugars generated after agar hydrolysis can be functionalized for use in biorefineries and biofuel production. The main objective of this study was to develop a sustainable agar hydrolysis process for bioethanol production using nanotechnology. Peroxidase-mimicking Fe₃O₄-MNPs were applied for agar degradation to generate agar hydrolysate-soluble fractions amenable to Saccharomyces cerevisiae and Escherichia coli during fermentation.

Fe₃O₄-MNP-treated (Fe₃O₄-MNPs, 1 g/L) agar exhibited 0.903 g/L of reducing sugar, which was 21-fold higher than that of the control (without Fe₃O₄-MNP-treated). Approximately 0.0181% and 0.0042% of ethanol from 1% of agar was achieved using Saccharomyces cerevisiae and Escherichia coli, respectively, after process optimization. Furthermore, different analytical techniques (FTIR, SEM, TEM, EDS, XRD, and TGA) were applied to validate the efficiency of Fe₃O₄-MNPs in agar degradation.

To the best of our knowledge, Fe₃O₄-MNP-treated agar degradation for bioethanol production through process optimization is a simpler, easier, and novel method for commercialization.