Antimicrobial peptides of fungal origin

Fungi are unique group of microorganisms accomplished of producing an array of fascinating metabolites. Their potential to yield antibiotics has been realized long back. Other metabolites of concern are also being produced by fungi. Fungi from different ecological niches are generating potential metabolites. Peptide antibiotics are being produced by many fungi. Antimicrobial peptides of fungal origin belong to mainly peptaibols and defensins. Trichoderma and related fungi are capable of producing peptaibols with extensive sequence diversity. Their uniqueness lies in having nonstandard amino acids such as α-aminoisobutyric acid (Aib) with high propensity. Antimicrobial activity of peptaibols is attributed to ion channel induction in membranes of target organisms. Species and strains of Trichoderma differ in their capability to produce peptaibols of various lengths. The antagonistic property of Trichoderma is endorsed to ability to produce these peptides. Microheterogenity has been observed in peptides due to interchange of amino acids in different positions. Defensins from fungi are rich in cysteine residues. Broad spectrum of activities has been assigned to fungal peptides which make them useful therapeutic molecules. Mass spectral-based peptide detection methods have revolutionized our understanding of structure of fungal peptides. These peptides are produced by nonribosomal pathway involving multifunctional peptide synthetases. Peptide databases are available owing to their unique biosynthetic pathways. Fungal peptides have been explored for their biotechnological applications in human medicine and plant protection. Several novel methods of delivery using nanotechnology are being developed. Current fungal fermentation technology and downstream processing will also aid in the mass production of useful fungal peptides.