[Soft Matter Café] Self-assembly of biological amphiphiles (biosurfactants): a focus on their membrane-forming properties

Microbial amphiphiles, known as microbial biosurfactants, are key molecules for the future of surfactants and amphiphiles, not only for their sustainable process of synthesis and production, but also for their chemical functionalities. Due to more and more stringent EU regulations, multinational chemical companies develop strategic production and partnerships for a long-term investment in this field. Indeed, their rich and astonishing phase behavior in water, their responsiveness to external stimuli combined to their sustainable origin, enhanced biodegradtion and mildness to the skin are attractive perspectives for the private sector as well as academia.
From a fundamental science perspective, knowledge of the phase behavior and solution properties of microbial biosurfactants is critical to conceive their application plan, as done for classical surfactants and lipids in the past fifty years. However, study of the phase behaviour of microbial biosurfactants is only a recent trend in the field [1] and recent studies from our and other groups have indeed shown curious properties, like a triple surfactant-lipid-gelator behaviour. [2]
In this communication, I will discuss these aspects with a special focus on the membrane-forming properties of selected microbial biosurfactants. Structural (SAXS, neutron diffraction) and dynamic (neutron spin echo) aspects will be discussed in detail with a comparison with more classical lipidic amphiphiles (e.g., phospholipids).

[1] N. Baccile, C. Seyrig, A. Poirier, S.A. Castro, S.L.K.W. Roelants, S. Abel, Self-assembly, interfacial properties, interactions with macromolecules and molecular modelling and simulation of microbial bio-based amphiphiles (biosurfactants). A tutorial review, Green Chem. 23 (2021) 3842–3944. https://doi.org/10.1039/d1gc00097g.
[2] N. Baccile, A. Poirier, C. Seyrig, P. Le Griel, J. Perez, D. Hermida-Merino, P. Pernot, S. Roelants, W. Soetaert, Chameleonic Amphiphile: the Unique Multiple Self-Assembly Properties of a Natural Glycolipid in Excess of Water, J. Colloid Interface Sci. 630 (2023) 404–415. https://doi.org/10.1016/j.jcis.2022.07.130.

About the speaker: Niki BACCILE is a physicochemist working in the field of Soft Matter. He received his Master diploma from the University of Padova, Italy and obtained a PhD in Materials’ Chemistry in 2006 at the Université Pierre et Marie Curie (now Sorbonne University), Paris (France). He worked as a post-doc at the Institute Charles Gerhardt in Montpellier (France) in 2007 and at the Max Planck Institute for Colloids and Interfaces, Potsdam-Golm (Germany), in 2008. Since 2008, he is full-time CNRS research fellow at Sorbonne University, Paris. He currently explores the self-organization properties of microbial biosurfactants and their potential use in soft matter.