Chemoenzymatic synthesis of alkyl-glycoside fatty Acid esters as biosurfactants

Sugar fatty acid esters (SFAEs), usually called sugar esters, are non-ionic surfactants which are characterized by excellent emulsifying, stabilizing and detergency properties. SFAEs are widely used in many market sectors (i.e. food, detergent, cosmetic and pharmaceutical industry) as they have many advantages over petrochemical-derived surfactants: they are tasteless, odorless, and fully biodegradable. Depending on carbon chain length and nature of the sugar head group, SFAEs cover a wide range of hydrophilic-lipophilic balance (HLB). SFAEs can be produced from renewable resources[1] through an esterification reaction between a sugar (Cn(H2O)n) and a fatty acid (RCO2H) catalyzed by a lipase.[2] Lactose, the main component of whey permeate which derives from dairy industry waste stream, was used as the starting material to synthesize butyl-β-D-galactoside through a transglycosylation reaction catalyzed by the immobilized β-galactosidase from Aspergillus oryzae in a ternary system composed of n-BuOH/acetone/McIlvane buffer 50 mM pH 4.5 (50/30/20).[3] Glucose, the by-product of the transglycosylation reaction, was converted into isomeric mixtures of glucosides by reaction with a number of naturally occurring alcohols in the presence of Amberlyst® 15. The resulting glucosides were submitted to a Novozyme® 435-catalyzed esterification with lauric, palmitic, and stearic acid in a solvent-free system, thus affording a set of SFAEs. Emulsifying properties of the SFAEs prepared as above reported are under evaluation. [1] N.S. Neta, J.A. Texteira, L.R. Rodrigues, Crit. Rev. Food Sci. Nutr., 2015, 55, 595-610 [2] N. Sarmah, D. Revathi, G. Sheelu, K. Yamuna, Rani, S. Sridhar, V. Mehtab, C. Sumana, Biotechnol. Prog., 2018, 34, 5-28 [3] D. Ahumada, F. Arenas, F. Martinez-Gòmez, C. Guerrero, A. Illanes, C. Vera, Front. Bioeng. Biotechnol., 2020, 8, 859 This abstract reports the preliminary results of the BioSurf project funded by Cariplo Foundation (Italy): “Circular Economy for a sustainable future – Call 2020”, ID 2020–1094, 06/01/2021-11/30/2023