Peptaibiomics: Screening for Polypeptide Antibiotics (Peptaibiotics) from Plant-ProtectiveTrichoderma Species

Abstract

were selected because of their antagonistic potential against Eutypa dieback and Esca which are fungal diseases of grapevine trunks. These isolates were screened for the production of a group of polypeptide antibiotics named peptaibiotics, including its subgroups peptaibols and lipopeptaibols. Fully-grown fungal cultures on potato-dextrose agar were extracted with CH 2 Cl 2 /MeOH, and these extracts were subjected to SPE using C 18 cartridges. The methanolic eluates were analyzed by on-line LC/ESI-MS n coupling -a method which is referred to as peptaibiomics . New seven-, ten-, and eleven-residue lipopeptaibols, with N-terminal alkanoyl, and Cterminal leucinol or isoleucinol residues were found and named lipostrigocins and lipopubescins. Furthermore, new 18-residue peptaibols named trichostromaticins and 19-residue peptaibols named trichostrigocins were discovered. One peptaibiotic carrying a free C-terminal valine (or isovaline) named trichocompactin XII was also sequenced. These results corroborate the hypothesis that peptaibiotics might contribute to the plant-protective action of their fungal producers. The data also point out that comparison of peptaibiotic sequences is of limited relevance in order to establish chemotaxonomic relationships among species of the genus Trichoderma.

Intact-cell MALDI-TOF mass spectrometry analysis of peptaibol formation by the genus Trichoderma/Hypocrea: can molecular phylogeny of species predict peptaibol structures?

“…Compared to the recently described peptaibiomics approach (Degenkolb et al, 2006a;Krause et al, 2006), our approach only partially identifies the peptaibols, but the information can be obtained from extremely small amounts of biomass and much more rapidly. Below, we discuss the consistency of our data with the available structural data and the implications of molecular genetic data for the study of the evolution of these NRPS systems.…”

“…brevicompactum, the same study describes trichocompactins and trichobrevins in CBS In a recent peptaibiomics study, plant-protective Trichoderma strains of different origins (T. strigosum, T. pubescens and T. stromaticum) were compared (Degenkolb et al, 2006a). The authors concluded from the differences between the strains and similarities between different species that peptaibol sequences are of limited relevance for chemotaxonomy.…”

“…DStrain numbers refer to Table 1. dWe detected no products in this survey; data were taken from Degenkolb et al (2006a).…”

“…Our data with the ex-type strain of T. strigosum are consistent with a detailed analysis of the same strain and strain T. cf. strigosum CBS 119777 (Degenkolb et al, 2006a) which produce trichostrigocins and tricholongins, respectively.…”

“…pubescens BBA 66989 and T. pubescens CBS 345.93, respectively (Degenkolb et al, 2006a). Interconversion of the 11-and 10-residue compounds would require alteration (Gly/Vxx) and deletion/insertion of one module, probably involving extensive alterations of the respective NRPS gene.…”