Ionic liquids as novel solvents for the synthesis of sugar fatty acid ester

• Published in: Biotechnology journal Vol. 9; no. 12; pp. 1565 - 1572
• Main Authors: Mai, Ngoc Lan, Ahn, Kihun, Bae, Sang Woo, Shin, Dong Woo, Morya, Vivek Kumar, Koo, Yoon-Mo
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-12-2014; WILEY‐VCH Verlag
• Subjects: Bio-surfactant; Esterification; Esters - chemical synthesis; Esters - chemistry; Glucose - chemistry; Imidazoles - chemistry; Ionic liquids; Ionic Liquids - chemistry; Laurates - chemical synthesis; Laurates - chemistry; Lipase - chemistry; Research Design; Response surface methodology; Solvents - chemistry; Sugar fatty acid ester; Surface-Active Agents - chemical synthesis; Surface-Active Agents - chemistry; Ionic liquids; Sugar fatty acid ester; Bio-surfactant; Response surface methodology
• ISSN: 1860-6768; 1860-7314
• DOI: 10.1002/biot.201400099

Sugar fatty acid esters are bio‐surfactants known for their non‐toxic, non‐ionic, and high biodegradability . With great emulsifying and conditioning effects, sugar fatty acids are widely used in the food, pharmaceutical, and cosmetic industries. Biosynthesis of sugar fatty acid esters has attracted growing attention in recent decades. In this study, the enzymatic synthesis of sugar fatty acid esters in ionic liquids was developed, optimized, and scaled up. Reaction parameters affecting the conversion yield of lipase‐catalyzed synthesis of glucose laurate from glucose and vinyl laurate (i.e. temperature, vinyl laurate/glucose molar ratio, and enzyme loads) were optimized by response surface methodology (RSM). In addition, production was scaled up to 2.5 L, and recycling of enzyme and ionic liquids was investigated. The results showed that under optimal reaction conditions (66.86 °C, vinyl laurate/glucose molar ratio of 7.63, enzyme load of 73.33 g/L), an experimental conversion yield of 96.4% was obtained which is close to the optimal value predicted by RSM (97.16%). A similar conversion yield was maintained when the reaction was carried out at 2.5 L. Moreover, the enzymes and ionic liquids could be recycled and reused effectively for up to 10 cycles. The results indicate the feasibility of ionic liquids as novel solvents for the biosynthesis of sugar fatty acid esters.
Biosynthesis of sugar fatty acid esters has attracted growing attention during the past decades. The authors use ionic liquids as novel superior solvents for the biocatalyzed‐synthesis of sugar fatty acid esters. They show that ionic liquids can dissolve a large amount of not only hydrophilic sugar but also hydrophobic fatty acids moieties. As a result, high conversion yield is maintained, and the lipase and ionic liquids could be recycled and reused effectively during the large scale.