Dormancy in heterocystous nitrogen fixing cyanobacteria: linking akinete shape and germination patterns

DE TEZANOS PINTO, PAULA; KUST, ANDREJA; ZAPOMELOVÁ, ELISKA

Granada

Congreso; ASLO; 2015

 Akinetesare dormant cells in nitrogen fixing cyanobacteria. Akinetes? shape differ amongspecies with similar ecologies. During germination: a) the cell wall is brokenand the endospore emerges and divides afterwards, or b) the endospore divideswithin the cell wall of the akinete before breaking the cell wall. Thesedifferent types of germination may imply reliance of external or internalnutrient availabilities, respectively. This, combined with the external sourceof nutrients may impact on recruitment success (and bloom). We experimentallyassessed if akinete shape was linked to germination patterns. We used 28strains of nitrogen fixing Cyanobacteria and forced them to express akinetes,by drying the cultures. We then stimulated germination by adding full strengthmedium WC during one week. Most strains germinated within the week of theexperiment, but not all, suggesting that favourable germinating conditions arespecies-specific. Most cylindrical akinetes germinated after breaking the akinetecell wall, whereas spherical and oval akinetes germinated within the cell wall.Germination patterns seem species specific, though rarely both germinationtypes occurred within a strain.