Novel approach to controlling toxic cyanobacteria: effect of 365 nm UV-A LED irradiation on six Microcystis aeruginosa strains and their eleven associated microcystins
Start Date
24-5-2022 5:45 PM
End Date
24-5-2022 7:00 PM
Abstract
Cyanobacterial blooms pose a threat to human and animal health due to the presence of cyanotoxins and challenge potable water treatment worldwide. Retrofitting water treatment plants is impractical, thus, alternative mitigation strategies such as in-reservoir treatment are needed.
Traditionally, UV-C (250 nm) is considered germicidal, however, UV-C treatment cannot be applied in situ because it is non-selective and would harm other biota. In a previous study (https://doi.org/10.1016/j.jenvman.2021.113519), UV-A 365 nm irradiation successfully removed Microcystis aeruginosa PCC 7813 cells and its four associated microcystins. To explore the suitability of this approach for in situ treatment of cyanobacteria and toxins, six geographically diverse Microcystis aeruginosa strains (SCIENTO, NIES 1099, B2666, PCC 7820, 7813 and 7806) and their eleven associated microcystins were exposed to 365 nm UV-A LED irradiation for seven days. UV-A 365 nm LED irradiation significantly decreased photosynthetic activity after only 24 hours of irradiation. Intra- and extracellular microcystin concentrations were markedly decreased in UV-A treated samples with a combined microcystin removal of 86%. Microcystins removal was analogue dependent and varied from 9% removal for MC-YR to complete degradation of MC-WR. UV-A irradiation was demonstrated to be an effective approach in the control of Microcystis aeruginosa and associated toxins.
Novel approach to controlling toxic cyanobacteria: effect of 365 nm UV-A LED irradiation on six Microcystis aeruginosa strains and their eleven associated microcystins
Cyanobacterial blooms pose a threat to human and animal health due to the presence of cyanotoxins and challenge potable water treatment worldwide. Retrofitting water treatment plants is impractical, thus, alternative mitigation strategies such as in-reservoir treatment are needed.
Traditionally, UV-C (250 nm) is considered germicidal, however, UV-C treatment cannot be applied in situ because it is non-selective and would harm other biota. In a previous study (https://doi.org/10.1016/j.jenvman.2021.113519), UV-A 365 nm irradiation successfully removed Microcystis aeruginosa PCC 7813 cells and its four associated microcystins. To explore the suitability of this approach for in situ treatment of cyanobacteria and toxins, six geographically diverse Microcystis aeruginosa strains (SCIENTO, NIES 1099, B2666, PCC 7820, 7813 and 7806) and their eleven associated microcystins were exposed to 365 nm UV-A LED irradiation for seven days. UV-A 365 nm LED irradiation significantly decreased photosynthetic activity after only 24 hours of irradiation. Intra- and extracellular microcystin concentrations were markedly decreased in UV-A treated samples with a combined microcystin removal of 86%. Microcystins removal was analogue dependent and varied from 9% removal for MC-YR to complete degradation of MC-WR. UV-A irradiation was demonstrated to be an effective approach in the control of Microcystis aeruginosa and associated toxins.