marine drugs Review Marine Biosurfactants: Biosynthesis, Structural Diversity and Biotechnological Applications Sonja Kubicki 1, Alexander Bollinger 1 , Nadine Katzke 1, Karl-Erich Jaeger 1,2 , 1, , 1, , Anita Loeschcke * y and Stephan Thies * y 1 Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, D-52425 Jülich, Germany 2 Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany * Correspondence:
[email protected] (A.L.);
[email protected] (S.T.) These authors contributed equally in conceptualising and coordinating activities. y Received: 17 June 2019; Accepted: 7 July 2019; Published: 9 July 2019 Abstract: Biosurfactants are amphiphilic secondary metabolites produced by microorganisms. Marine bacteria have recently emerged as a rich source for these natural products which exhibit surface-active properties, making them useful for diverse applications such as detergents, wetting and foaming agents, solubilisers, emulsifiers and dispersants. Although precise structural data are often lacking, the already available information deduced from biochemical analyses and genome sequences of marine microbes indicates a high structural diversity including a broad spectrum of fatty acid derivatives, lipoamino acids, lipopeptides and glycolipids. This review aims to summarise biosyntheses and structures with an emphasis on low molecular weight biosurfactants produced by marine microorganisms and describes various biotechnological