Cyanobacterial harmful algal blooms ('cyanoHABs') occur worldwide — causing detrimental effects to ecosystems and local economies — and can produce toxins that pose threats to human health and limit potable water supplies. Microcystis and other genera of cyanobacteria produce a compound known as Microcystin-LR (MCLR) that is toxic to the liver and inhibits nerve functions, muscle activity, and cellular metabolism. Conventional municipal water treatment techniques cannot remove MCLR.
At the recent 7th Symposium on Harmful Algae in the U.S. held in Sarasota, Fla., University of Tennessee researchers reported initial findings from their NCCOS-sponsored project to develop a workable, affordable commercial biofiltering system that uses bacteria to removeMCLR from public drinking water supplies. Some bacteria co-occurring with cyanoHABs degrade MCLR to use as an energy source. One bacteria strain, identified as Pseudomonas alcaligenes, degraded up to 90 percent of MCLR toxin in 10 days.
The team's ongoing experiments are characterizing MCLR degradation rates and byproducts with the long-term goal of identifying bacteria that can be deployed as part of commercial toxin remediation strategies for potable water. The results of this research will be applicable to Lake Ontario and Lake Erie in the U.S., which have increasing cyanobacteria blooms.