Isolation and Characterization of Lake Erie Bacteria that Degrade the Cyanobacterial Microcystin Toxin MC-LR Article (Faculty180)

cited authors

  • Thees, Alison; Atari, Ealla; Birbeck, Johnna; Westrick, Judy A; Huntley, Jason F


  • Microcystin-LR (MC-LR) is a cyclic hepatotoxin produced by cyanobacteria, including sp. and sp. Harmful algal blooms (HABs) in Lake Erie have become a major human health concern in recent years, highlighted by the August 2014 city of Toledo, Ohio, municipal water "do not drink" order that affected nearly 500,000 residents for 3 days. Given that microcystin degrading bacteria have been reported from HAB-affected waters around the world, we hypothesized that MC-LR degrading bacteria could be isolated from Lake Erie. To test this hypothesis, 13 water samples were collected from various Lake Erie locations during the summers of 2014 and 2015, MC-LR was continuously added to each water sample for 3 to 5 weeks to enrich for MC-LR-degrading bacteria, and MC-LR was quantitated over time. Whereas MC-LR was relatively stable in sterile-filtered lake water, robust MC-LR degradation (up to 19 ppb/day) was observed in some water samples. Following the MC-LR selection process, 67 individual bacterial isolates were isolated from MC-LR degrading water samples and genotyped to exclude potential human pathogens, and MC-LR degradation by smaller groups of bacterial isolates (, groups of 22 isolates, groups of 11 isolates, ) was examined. Of those smaller groups, selected groups of four to five bacterial isolates were found to degrade MC-LR into non-toxic forms and form robust biofilms on siliconized glass tubes. Taken together, these studies support the potential use of isolated bacterial isolates to remove MC-LR from drinking water.

publication date

  • 2019

published in

start page

  • 138

end page

  • 149


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