Molecular insights into toxic bloom development through metaproteomics

Metaproteomics is an emerging field enabling insights into the complex interplay between microorganisms and their influence on biogeochemical processes. The field is uniquely relevant to the study of complex cyanobacterial bloom systems, with the potential to map bloom initiation, maintenance and senescence at the molecular level. Metaproteomics was applied to profile the seasonal regulation of a cyanobacterial bloom in an Australian wetland. The site was home to a transient flying fox colony contributing as a major nutrient source. 16s and shotgun metagenomics were applied to understand taxonomic distributions over the course of 1 year. Amplification of mcyE within the community was used to infer microorganisms containing the microcystin biosynthetic gene cluster. Protein and peptide-level identifications were used to infer the contribution of major taxonomic groups to nutrient flux based on the expression of metabolic enzymes and transporter families. Communities were investigated in the sediment and upper pelagic space to enable insights into species recruitment and potential contributions to bloom initiation. While this study is ongoing, it offers initial molecular insights into the drivers of toxic cyanobacterial blooms, and potential triggers for bloom development.