Visualizing the spatial distribution of secondary metabolites produced by marine cyanobacteria and sponges via MALDI-TOF imaging

Abstract

Marine cyanobacteria and sponges are prolific sources of natural products with therapeutic applications. In this paper we introduce a mass spectrometry based approach to characterize the spatial distribution of these natural products from intact organisms of differing complexities. The natural product MALDI-TOF-imaging (npMALDI-I) approach readily identified a number of metabolites from the cyanobacteria Lyngbya majuscula 3L and JHB, Oscillatoria nigro-viridis, Lyngbya bouillonii, and a Phormidium species, even when they were present as mixtures. For example, jamaicamide B, a well established natural product from the cyanobacterium Lyngbya majuscula JHB, was readily detected as were the ions that correspond to the natural products curacin A and curazole from Lyngbya majuscula 3L. In addition to these known natural products, a large number of unknown ions co-localized with the different cyanobacteria, providing an indication that this method can be used for dereplication and drug discovery strategies. Finally, npMALDI-I was used to observe the secondary metabolites found within the sponge Dysidea herbacea. From these sponge data, more than 40 ions were shown to be co-localized, many of which were halogenated. The npMALDI-I data on the sponge indicates that, based on the differential distribution of secondary metabolites, sponges have differential chemical micro-environments within their tissues. Our data demonstrate that npMALDI-I can be used to provide spatial distribution of natural products, from single strands of cyanobacteria to the very complex marine assemblage of a sponge.

Enzymatic resistance to the lipopeptide surfactin as identified through imaging mass spectrometry of bacterial competition

“…However, the relative differences in growth, development, and metabolism of the two organisms in coculture obscure the functions of individual metabolites. As an approach to monitoring natural products, including surfactin, during competitive interactions between B. subtilis and streptomycetes, we used MALDI-imaging mass spectrometry (IMS) (31,40). B. subtilis and Streptomyces spp.…”

“…We used IMS to monitor the production and fate of natural product metabolites in the competitive interaction between B. subtilis NCIB3610 and S. Mg1 (31,40). Application of IMS enabled spatial tracking of metabolites in the mass range that we surveyed, 500-3000 m/z.…”

Desorption electrospray ionization mass spectrometry reveals surface-mediated antifungal chemical defense of a tropical seaweed

“…The Dorrestein and Gerwick groups demonstrated the utility of matrix-assisted laser desorption ionization time-offlight mass spectrometry (MALDI-TOF MS) for pinpointing secondary metabolite locations within marine microbeinvertebrate assemblages (21,22), and this strategy may prove widely applicable in assigning biosynthetic origins and distributions of chemical defenses within tissues or cell types. Further, time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been recently applied in assessing antibiotic distributions on Streptomyces coelicolor bacterial culture surfaces (23).…”

MALDI Imaging Mass Spectrometry of Fresh Water Cyanobacteria: Spatial Distribution of Toxins and Other Metabolites

“…13 This technique has also been applied for analysis of microbial natural products, 14 microbial interactions 15 and metabolic profiling of microorganisms. 16 Recently, MALDI-IMS has been tested for filamentous marine cyanobacteria, 17 showing the spatial distribution of natural products. The main challenges in MALDI-IMS are the sample preparation and the spatial resolution.…”