Effects of light intensity on pigments, cell migration, and toxin levels in Microcystis aeruginosa

Session: Poster session

Dominique Derminio, SUNY, College of Environmental Science & Forestry, [email protected]
Gregory Boyer, SUNY-ESF, [email protected]

Abstract

Cyanobacteria gather light energy needed for growth within photosystem II using a phycobilisome. Phycobilisomes contain three major pigment-proteins: allophycocyanin, phycocyanin (PC) and phycoerythrin (PE). These latter two proteins, PC and PE, form the light gathering antenna complex. To understand how this antenna changes with light intensity, an 18-hour experiment was conducted on a natural toxic cyanobacterial harmful algal bloom (cyanoHABs) in Lake Neatahwanta (Fulton, NY, USA). Light intensity, cyanobacteria biomass as both cell number and pigment fluorescence, and toxicity were measured at 2-hr intervals at four depths between the hours of 4:00 am and 10:00 pm. Cell numbers (Microcystis) and toxicity per liter did not significantly change with time of day or depth. In contrast, pigments (chl-a and PC) did significantly vary with time of day and depth. There was a significant difference in PC/PE ratio based on fluorescence over the course of the experiment. This study will improve our fundamental understanding of how Microcystis pigment composition responds to a changing light field and has important implications for the use of fluorescent techniques in monitoring cyanoHABs.

1. Keyword
harmful algal blooms

2. Keyword
Microcystis

3. Keyword
photosynthesis

4. Additional Keyword
pigments

5. Additional Keyword
monitoring