Reaction of Sulfur and Sustainable Algae Oil for Polymer Synthesis and Enrichment of Saturated Triglycerides

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.

Sulfur–oleylamine copolymer synthesizedviainverse vulcanization for the selective recovery of copper from lithium-ion battery E-waste

“…The proton peak of alkene shows doublet of doublet, which could be a result of E / Z isomerization, through the addition of a RS˙ radical to the cis alkene, followed by β-elimination to form trans alkene. 41 The terminal methyl groups are present in the polymer around δ 0.85 ppm. However, there is a shift in amine proton peaks in the polymer from 1.06 ppm in monomer to 1.6 ppm, this behaviour is due to N–H resonance as reported in previous literatures 42 (denoted as grey rectangle in Fig.…”

Detoxification of bisphenol A via sulfur-mediated carbon–carbon σ-bond scission

“…Composites produced in this manner can exhibit exceptional thermomechanical properties, and can be thermally recycled under relatively mild conditions, owing to the thermal reversibility of S-S bond breakage and bond formation. [13][14][15][16][17][18] Fully-sustainable sulfur composites can be prepared when petroleum-derived olens are replaced with biologically-produced monomers, such as fatty acids, [19][20][21] triglycerides, [22][23][24][25][26] terpenoids, 25,[27][28][29][30] amino acid derivatives, 31 lignin derivatives, [32][33][34][35] cellulose derivatives, 30,36 and even raw lignocellulosic biomass. 37,38 Reaction temperatures for preparing or shaping HSMs can be lowered by using catalysts, 39 mechanochemical methods, 40 ternary mixtures, 41 pre-formation of more reactive sulfur species, 42 using nucleophiles to fuse materials together through S-S metathesis, 43 or by compression-molding of materials.…”

Integration of the Exogenous Tuning of Thraustochytrid Fermentation and Sulfur Polymerization of Single-Cell Oil for Developing Plant-like Oils

“…Thus, it was imperative to develop a downstream processing method to enrich oils with a desired degree of saturation or unsaturation. In this context, we recently demonstrated the use of elemental sulfur to separate saturated triglycerides and polyunsaturated triglycerides from thraustochytrid oil with the development of a polyunsaturated-triglyceride enriched sulfur polymer that has several applications [ 18 ]. The objective of the study was to tune the fatty acid profile of the thraustochytrid oil employing fermentation and subsequently use inverse vulcanization to separate saturated fatty acids from PUFAs (such as omega-3 fatty acids) so that the resultant oil can mimic the plant-oil-like profile.…”

“…Furthermore, the oil containing more saturated fatty acids (SFAs) and monosaturated (MUFAs) and less polyunsaturated fatty acid (PUFA) was extracted from the thraustochytrid biomass that was grown in an optimised fermentation medium (using the above-mentioned compounds), and extracted oil was subjected to further downstream processing using hydrogenation and a sulfur polymerization process. Heterogeneous catalytic hydrogenation has been used as a benchmark process for SFAs and MUFA production from PUFA-containing oil [ 18 , 19 ]. In addition, sulfur polymerization resulted in triglyceride-containing sulfur co-polymer because the sulfur reacts with the unsaturated triglycerides in the oil, with the chance of recovering SFA and MUFA containing oil from the polymer through ethanol extraction [ 18 ].…”

“…Heterogeneous catalytic hydrogenation has been used as a benchmark process for SFAs and MUFA production from PUFA-containing oil [ 18 , 19 ]. In addition, sulfur polymerization resulted in triglyceride-containing sulfur co-polymer because the sulfur reacts with the unsaturated triglycerides in the oil, with the chance of recovering SFA and MUFA containing oil from the polymer through ethanol extraction [ 18 ]. To the best of our knowledge, this is the first such study where upstream and downstream processing processes have been integrated to minimise challenges associated with biotechnological SCO production.…”