Light as a possible regulator of MIB-producing Planktothrix in source water reservoir, mechanism and in-situ verification

Publication date: September 2019Source: Harmful Algae, Volume 88Author(s): Zeyu Jia, Ming Su, Tingting Liu, Qingyuan Guo, Qi Wang, Michael Burch, Jianwei Yu, Min YangAbstractThe typical musty/earthy odor-causing compound, 2-methylisoborneol (MIB), is usually associated with the occurrence and proliferation of benthic/subsurface-living cyanobacteria in source water. Control of MIB-producing cyanobacteria in source water may greatly reduce the processing burden for drinking water treatment plants. We explored the mechanism and feasibility of restricting the growth of subsurface-living Planktothrix sp. by reducing underwater light availability. The effects of light intensity (5, 17, 36, 85, and 250 μmol photons m−2 s−1) on the growth and MIB production of Planktothrix sp. were first determined using batch culture, followed by an in-situ experiment deployed at different depths (0.5, 1.5, 3.5, and 5.0 m) in a drinking source water reservoir (Miyun Reservoir, China) to verify the laboratory results. The optimum conditions for growth (7.5 × 108 cells L−1) and MIB production ((1300 ± 29) μg L−1) of Planktothrix sp. were achieved at 85 μmol photons m−2 s−1 in the laboratory and at 1.5 m (the corresponding average light intensity of 66 μmol photons m−2 s−1) in the field. The minimum light requirement for the growth of Planktothrix sp. (4.4 μmol photons m−2 s−1) was determined according to the laboratory data. While ...
Source: Harmful Algae - Category: Environmental Health Source Type: research