MALDI Imaging of Fungal Interactions: A tool to facilitate the isolation of fungal inhibitors from marine bacteria

摘要

Imaging mass spectrometry can be used to study other microorganisms besides bacteria directly on the agar plate as was demonstrated for fungi. Media containing 100percent sea salt water such as M1 yielded sufficient signal to noise ratios in MALDI-IMS to allow visualization of numerous bacterial and fungal metabolites. Isolation of antifungal metabolite produced by pseudomonaltermonas OT59 was facilitated by the use of imaging mass spectrometry. Alteramide A, previously identified as a cytotoxic metabolite appeared responsible for the antifungal activity. HMBC and HSQC are still needed for full structure elucidation. Upon exposure to UV light this compound converted to a cycloaddition product which no longer displayed antifungal activity. Structure elucidation of the weak m/z 495 antifungal product is in progress. Antibacterial metabolites produced by OT59 are currently being isolated using a similar process.