Heterogeneity of cyanobacterial gas-vesicle volume and metabolic activity

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research Centre

MDFRC item.

The literature suggests that relative gas-vesicle volume and metabolic activity differ between individuals within natural populations of cyanobacteria. We demonstrate, using flow cytometry and fluorescein diacetate (FDA) conversion rates, that individual relative gas-vesicle volumes differed by 6.7- and 4.6-fold, and individual cell photosynthetic rates ranged from 0.026 to 0.127 and from 0.075 to 2.415 fmol O2 cell–1 min–1 within phosphorus-starved and phosphorus-replete Microcystis aeruginosa populations, respectively. The observation that there is considerable heterogeneity in gas-vesicle volume and cell metabolic activity in cultured populations suggests that this could also contribute to heterogeneity in buoyancy of field populations.