Phase Behaviour, Functionality, and Physicochemical Characteristics of Glycolipid Surfactants of Microbial Origin

Abstract

Growing demand for biosurfactants as environmentally friendly counterparts of chemically derived surfactants enhances the extensive search for surface-active compounds of biological (microbial) origin. The understanding of the physicochemical properties of biosurfactants such as surface tension reduction, dispersion, emulsifying, foaming or micelle formation is essential for the successful application of biosurfactants in many branches of industry. Glycolipids, which belong to the class of low molecular weight surfactants are currently gaining a lot of interest for industrial applications. For this reason, we focus mainly on this class of biosurfactants with particular emphasis on rhamnolipids and sophorolipids, the most studied of the glycolipids.

Green Surfactants (Biosurfactants): A Petroleum-Free Substitute for Sustainability─Comparison, Applications, Market, and Future Prospects

“…Glycolipids are the class of low molecular weight molecules that have been the subject of the greatest research, with the most commonly known being the sophorolipids (sophorose lipids, SPLs), rhamnolipids (rhamnose lipids, RMLs), trehalose lipids, and mannosylerythritol lipids (MELs). − Glycolipids have been reported to have wide ranges of applications in pharmaceutical formulations. − …”

Rhamnolipid Self-Aggregation in Aqueous Media: A Long Journey toward the Definition of Structure–Property Relationships

“…Likely due to the difficulty of handling pure products and to the fact that even small changes in the composition of the congeners lead to significant differences in the behavior of rhamnolipids, the study of physicochemical properties of this class of biosurfactants has been somehow overlooked, with respect to research on their production and applications. Numerous reports on the characterization of rhamnolipids in terms of aggregation and surface/interface properties are present in the literature; moreover, quite recently, excellent papers reviewed the physicochemical properties of biosurfactants [ 4 , 44 , 45 , 122 , 142 ], including rhamnolipids. However, what is still lacking, in our opinion, is an in-depth overall analysis of the surface and aggregation behavior of this class of molecules as a function of the pH, the presence of salts or additives, the purity of the rhamnolipid, or the composition of the mixture employed.…”

Production and characterization of lipopeptide biosurfactant from a new strain ofPseudomonas antarctica28E using crude glycerol as a carbon source

“…Surfactants are described as active ingredients, found in household and industrial-scale cleaning agents. 1 Their activity derives from the surface or interfacial tension reduction properties, which increase the solubility of non-aqueous phase liquids. Despite their numerous benefits, the high toxicity of surfactants is not without significance.…”

“…3 However, in a time of ecological crisis there is a growing demand for environmentally friendly agents. 1 Therefore, biosurfactants are increasingly taking the place of their synthetic counterparts. Biosurfactants are surface-active compounds physiologically secreted by microorganisms for utilization of hydrocarbons.…”