Extremophiles as a Source of Antimicrobial Peptides

There is a majority of information about antimicrobial peptides (AMPs) produced by lactic acid bacteria (LAB) due to their GRAS (generally recognized as safe) status and probiotic characteristic. However, AMPs produced by LAB bacteria are not completely effective against several Gram-positive and Gram-negative pathogens. Therefore, there is still a need to search for microbes with the ability to produce novel and effective antimicrobials. Extreme niches provide tremendous opportunities to find new bacteria with distinct features. In recent years, scientists have been focused on studies of secondary metabolites produced by extremophiles. They are characterized by an enormous ability to synthesize numerous chemicals. AMPs derived from microbes with active metabolisms that can adapt to a variety of extreme environments have long been sought after. Bacteria and archaea from extreme environments are a resource that is just beginning to be exploited in research toward the production of biomolecules. However, some species have been studied extensively for their respective AMPs production. This chapter summarizes information on the potential of extremophiles as host microorganisms for the production of AMPs. We focused on the present knowledge on AMPs produced by bacteria and archaea and their activity.