5-07: Biopolymers from Proteins extracted from Microalgae via Flash Hydrolysis Process

Microalgae can be used to produce advanced biofuels and biobased products. However, for achieving a successful application of algae to biofuels at large scales require better energy balance and technological breakthroughs in the area of algae cultivation, harvesting, processing, and resource utilization. The huge demand for water and nutrients possess considerable challenges and necessitates recycling of nutrient and bioproducts development. In view of these challenges, we developed a flash hydrolysis process which is capable of fractionating lipids and proteins contained in microalgae. The fractionated lipids are suitable for advanced biofuels application whereas hydrolyzed proteins are available as peptides and amino acids. Flash hydrolysis process capitalizes on the difference in reaction kinetics of algae components (proteins, carbohydrates, and lipids) to hydrolyze proteins in the liquid phase in seconds of residence times in a continuous flow reactor under subcritical water medium.

In this study, the water-soluble peptides and amino acids are pre-concentrated and characterized for making biopolymers. The study focuses on repolymerizing the amino acids/peptides using condensation polymerization techniques to produce biopolymers. As an example β-alanyl N-succinamide polymers can be made through the proposed process. The flash hydrolysis process was optimized in at 280°C where we preserve majority of peptides and amino acids in the solution. Nearly 70 wt% of nitrogen present in Scenedesmus sp. was hydrolyzed as peptides and amino acids. A total of 15 amino acids were quantified by ion chromatography. The focus of our study to characterize peptides and amino acids recovered after flash hydrolysis for producing different biopolymers.