A lipopeptide is a molecule consisting of a lipid connected to a peptide. They are able to self-assemble into different structures. Many bacteria produced these molecules as a part of their metabolism, especially those of the genus Bacillus, Pseudomonas and Streptomyces. Certain lipopeptides are used as antibiotics. Other lipopeptides are toll-like receptor agonists. Certain lipopeptides can have strong antifungal and hemolytic activities. It has been demonstrated that their activity is generally linked to interactions with the plasma membrane, and sterol components of the plasma membrane could play a major role in this interaction. It is a general trend that adding a lipid group of a certain length (typically C10–C12) to a lipopeptide will increase its bactericidal activity. Lipopeptides