Recovery and Purification Techniques Used for AMPs Produced by Lactic Acid Bacteria

The biotechnological research on lactic acid bacteria (LAB), which produce antimicrobial peptides (AMPs), has involved different efforts since the beginning of the last century, among other aspects, isolation, selection, and improvement of strains; culture media and operating conditions during fermentation; methods of recovery and purification of the produced AMPs, among others. In particular, regarding the recovery and purification of AMPs, the methods depend on the AMPs chemical nature, which determines the interactions of these biomolecules with other chemical species under the direct influence of the surrounding “chemical environment”. For example, the precipitation of peptides (i.e. by salts—ammonium sulphate- or solvents –acetone-); interactions due to electrical charge -attraction or rejection (i.e. ion exchange chromatography); physical interactions (i.e. gel permeation chromatography); solubility in different solvents (i.e. liquid–liquid extraction), among others. This chapter presents the fundamentals of the physicochemical interactions of AMPs that determine the methods generally used for their study in basic research, technology development, and industrial production, with the main achievements and perspectives.