Biodegradation of microcystins by microbiota of duckweed Spirodela polyrhiza

Here we analysed the biodegradation of microcystin-RR, MC-LR and MC-LF by microbiota of the macrophyte Spirodela polyrhiza.The NGS-based profiling of microbial consortia showed that there were no differences in the composition of bacterial communities across experimental treatments, yet the total bacterial abundance changed significantly. In all variants, Proteobacteria, which are well-known MC-degraders, dominated the bacterial community. The relative abundance of Bacteroida and Firmicutes varied between 7,6 to 14,9% and 2 to 6,4%, respectively. Our findings indicated that the microbiota associated with S. polyrhiza can biodegrade MC-RR and MC-LR variants in slightly different biochemical pathways than previously described. Apart from proteases that cut peptide bonds, other enzymes also participate in degradation. The potential of the microbiota of aquatic plants to biodegrade MCs can be environmentally relevant and further studies in this field are required.