Persistence of Only a Minute Viable Population in Chlorotic Microcystis aeruginosa PCC 7806 Cultures Obtained by Nutrient Limitation

摘要: Cultures from the cyanobacterial strain Microcystis aeruginosa PCC 7806 submitted to nutrient limitation become chlorotic. When returned rich conditions these cultures regain their green colour. The aim of this study was verify whether cells in could be considered resting stages allowing survival periods starvation as has been reported for Synechococcus 7942. experiments with were carried out parallel rule possibility that any results obtained due our particular experimental conditions. 7942 comparable literature. For a different response observed. Analysis chlorotic by flow cytometry showed phenotype population not homogenous: amount nucleic acids about same all but only around one percent emitted red autofluorescence indicating presence chlorophyll. Monitoring reversion chlorosis re-greening most likely result division small autofluorescent originally present cultures. This assumption confirmed analysing integrity DNA and membrane permeability Most degraded integrity. Thus, contrary what other genera, are dead. It is interesting note double strength ASM-1 medium differ respect metabolism: levels emission higher ability convert fluorescein diacetate heterogeneous when compared differentiated metabolic state allow them persist which loses viability; persistent can detected maintained more than year.