Abstract: A clarified algae extract used to obtain a composition having antibacterial and/or antifungal activity, said extract being obtained according to a method comprising the stages of release of the intracellular content of the algae cells and clarification by filtration of said intracellular content, in order to obtain a clarified filtration permeate, said extract comprising a molecular fraction containing halogenated organic molecules having a molecular weight of more than 10,000.