Peptaibols: stable markers of fungal development in the marine environment.

Different peptaibols were observed in both fresh and frozen marine sediments collected from a marine area devoted to bivalve culture (Fier d'Ars, Atlantic coast, France). The identification of the peptaibols was based on a three-step mass-spectrometric analysis: observation of doubly charged ions with a characteristic isotopic profile, cleavage and observation of C- and N-terminal fragments, and partial sequencing of the N-terminal segments. The MS characteristics indicated numerous similarities between the peptaibols detected and those produced by different strains of Trichoderma species isolated from fresh sediments.

Toxicity assessment of peptaibols and contaminated sediments on Crassostrea gigas embryos.

Peptaibols are known membrane-modifying peptides that were recently detected in marine sediments and mussels collected from a shellfish farming area (Fier d'Ars, Atlantic coast, France). In this investigation, embryotoxicity bioassays with oysters (Crassostrea gigas) were performed to assess acute toxicity of alamethicin and different groups of peptaibols produced by a Trichoderma longibrachiatum strain isolated from marine environment. C.

Determination of peptaibol trace amounts in marine sediments by liquid chromatography/electrospray ionization-ion trap-mass spectrometry.

Extraction followed by reverse phase liquid chromatography (LC)/electrospray ionization-ion trap-mass spectrometry (ESI-IT-MS) analysis has been successfully developed for the determination of peptaibols, fungal toxic metabolites, in marine sediments. Spiking experiments showed that the mean recovery of target compounds exceeded 85% at a spiking level of 10 ng/g of sediment (wet weight). Detection and quantification limits were 250 and 830 pg/g of sediment, respectively.

New short peptaibols from a marine Trichoderma strain.

The production of peptaibols by a marine-related Trichoderma longibrachiatum strain was studied using electrospray ionisation multiple-stage ion trap mass spectrometry (ESI-MSn-IT) and gas chromatography/electron impact mass spectrometry (GC/EI-MS). Two major groups of peptaibols were identified, those with long sequences (20 amino acids) and others with short sequences (11 amino acids). This paper describes the methodology used to establish the sequences of short peptaibols in a mixture without previous individual separation.