Reaction of Sulfur and Sustainable Algae Oil for Polymer Synthesis and Enrichment of Saturated Triglycerides
Adarsha Gupta, Max J. H. Worthington, Harshal D. Patel, Martin R. Johnston, Munish Puri, Justin M. Chalker
Abstract
There is growing interest in the biobased production of lipids from algae. These lipids have a range of uses including nutritional supplements and precursors to biodiesel. Single-cell thraustochytrids are especially attractive in this regard in that they can produce over 50% of their weight as triglycerides. Furthermore, the distribution of saturated and unsaturated triglycerides can be modulated by changes in strain variation and fermentation conditions. Nonetheless, there remains a need for versatile downstream processing to enrich these so-called “single cell oils” into classes based on degree of unsaturation. In this study, we report a novel strategy for enriching saturated triglycerides produced in thraustochytrids. The method features direct reaction of elemental sulfur with the algae oil extract. Sulfur copolymerizes with >90% of the unsaturated triglycerides, providing a new route to a class of materials previously used in environmental remediation, Li–S battery cathodes, slow-release fertilizers, and insulation. The unreacted oil is enriched in saturated triglycerides, which can be isolated by extraction for potential use in biodiesel production. In this way, a single batch of sustainably produced algae oil can be converted into multiple useful products in a single step.