Cyanobacteria and Eukaryotic Microalgae as Emerging Sources of Antibacterial Peptides

• Main Authors: Verónica Rojas, Luis Rivas, Constanza Cárdenas, Fanny Guzmán
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Molecules
• Subjects: cyanobacteria; microalgae; peptide; antimicrobial; antibacterial activity; bioactive compounds
• Online Access: https://www.mdpi.com/1420-3049/25/24/5804

Cyanobacteria and microalgae are oxygen-producing photosynthetic unicellular organisms encompassing a great diversity of species, which are able to grow under all types of extreme environments and exposed to a wide variety of predators and microbial pathogens. The antibacterial compounds described for these organisms include alkaloids, fatty acids, indoles, macrolides, peptides, phenols, pigments and terpenes, among others. This review presents an overview of antibacterial peptides isolated from cyanobacteria and microalgae, as well as their synergism and mechanisms of action described so far. Antibacterial cyanopeptides belong to different orders, but mainly from Oscillatoriales and Nostocales. Cyanopeptides have different structures but are mainly cyclic peptides. This vast peptide repertoire includes ribosomal and abundant non-ribosomal peptides, evaluated by standard conventional methodologies against pathogenic Gram-negative and Gram-positive bacteria. The antibacterial activity described for microalgal peptides is considerably scarcer, and limited to protein hydrolysates from two <i>Chlorella</i> species, and few peptides from <i>Tetraselmis suecica.</i> Despite the promising applications of antibacterial peptides and the importance of searching for new natural sources of antibiotics, limitations still persist for their pharmaceutical applications.