Interaction of rhamnolipids with model biomembranes of varying complexity.

Rhamnolipids represent a large class of biologically produced surface-active compounds, which participate in various essential cellular functions. While many studies have reported on the antibacterial and antifungal effects of rhamnolipids, only a few tried to describe the molecular mechanisms underlying these effects. Here, we first review the literature on rhamnolipid-phospholipid interactions and then add own results on a prominent monorhamnolipid congener, RhaC10C10. By focusing on the interactions between the rhamnolipid and lipid model membranes of different complexity, up to heterogeneous raft-like model biomembranes, we gained new insights into changes of the lateral membrane organization and morphological changes of membrane vesicles induced by partitioning of the rhamnolipid. To this end, AFM, confocal fluorescence microscopy, and Laurdan fluorescence spectroscopy analyses were employed. In summary, we provide a concise description of the physio-chemical effects rhamnolipids impose on lipid membranes, which help us to understand their physiological role.