Antifungal membranolytic activity of the tyrocidines against filamentous plant fungi.

The tyrocidines and analogues are cyclic decapeptides produced by Brevibacillus parabrevis with a conserved sequence of cyclo(D-Phe-Pro-X-x-Asn-Gln-X-Val-X-Leu) with Trp/Phe in the aromatic dipeptide unit, Lys/Orn as their cationic residue and Tyr (tyrocidines), Trp (tryptocidines) or Phe (phenicidines) in position 7. Previous studies indicated they have a broad antifungal spectrum with the peptides containing a Tyr residue in position 7 being more active than those with a Phe or Trp residue in this position. Detailed analysis of antifungal inhibition parameters revealed that Phe-D-Phe in the aromatic dipeptide unit lead to more consistent activity against the three filamentous fungi in this study.

Antifungal peptides: To be or not to be membrane active.

Most antifungal peptides (AFPs), if not all, have membrane activity, while some also have alternative targets. Fungal membranes share many characteristics with mammalian membranes with only a few differences, such as differences in sphingolipids, phosphatidylinositol (PI) content and the main sterol is ergosterol. Fungal membranes are also more negative and a better target for cationic AFPs.

Inhibition of agronomically relevant fungal phytopathogens by tyrocidines, cyclic antimicrobial peptides isolated from Bacillus aneurinolyticus.

The tyrocidines, a complex of analogous cyclic decapeptides produced by Bacillus aneurinolyticus, exhibited noteworthy activity against a range of phytopathogenic fungi, including Fusarium verticillioides, Fusarium solani and Botrytis cinerea. The activity of the tyrocidine peptide complex (Trc mixture) and purified tyrocidines exhibited minimum inhibition concentrations below 13 µg ml(-1) (~10 µM) and was significantly more potent than that of the commercial imidazole fungicide, bifonazole. Although the tyrocidines' activity was negatively influenced by the presence of Ca(2+), it remained unaffected by the presence of Mg(2+), Na(+) and K(+).

Synergistic activity of the tyrocidines, antimicrobial cyclodecapeptides from Bacillus aneurinolyticus, with amphotericin B and caspofungin against Candida albicans biofilms.

Tyrocidines are cationic cyclodecapeptides from Bacillus aneurinolyticus that are characterized by potent antibacterial and antimalarial activities. In this study, we show that various tyrocidines have significant activity against planktonic Candida albicans in the low-micromolar range. These tyrocidines also prevented C.

A novel 96-well gel-based assay for determining antifungal activity against filamentous fungi.

In recent years the global rise in antibiotic resistance and environmental consciousness lead to a renewed fervour to find and develop novel antibiotics, including antifungals. However, the influence of the environment on antifungal activity is often disregarded and many in vitro assays may cause the activity of certain antifungals to be overestimated or underestimated. The general antifungal test assays that are economically accessible to the majority of scientists primarily rely on visual examination or on spectrophotometric analysis.