Heterogeneity of cyanobacterial gas-vesicle volume and metabolic activity

The literature suggests that relative gas-vesicle volume and metabolic acti vity differ between individuals within natural populations of cyanobacteria . We demonstrate, using flow cytometry and fluorcscein diacetate (FDA) conv ersion rates, that individual relative gas-vesicle volumes differed by 6.7- and 4.6-fold, and individual cell photosynthetic rates ranged from 0.026 t o 0.127 and from 0.075 to 2.415 fmol O-2 cell(-1) min(-1) within phosphorus -starved and phosphorus-replete Microcystis aeruginosa populations, respect ively. The observation that there is considerable heterogeneity in gas-vesi cle volume and cell metabolic activity in cultured populations suggests tha t this could also contribute to heterogeneity in buoyancy of field populati ons.