Luxury phosphorus uptake in cyanobacteria

Life in environments with scarce, fluctuating phosphorus (P) availability poses a variety of challenges to cyanobacteria. To cope with them, cyanobacteria developed diverse acclimations including the capability of luxury phosphorus uptake (LPU) - taking up P in excess of the current metabolic demand. Whereas the specific acclimations to P starvation are relatively well studied, the phenomenology and underlying mechanisms of LPU are greatly underexplored despite its importance for understanding nutrient-driven rearrangements in aquatic ecosystems. We studied the LPU occurring after re-feeding of P-deprived cells of Nostoc sp. PCC 7118 with inorganic phosphate (Pi). The study was focused on the kinetics of Pi uptake, turnover of P reserves, ultrastructural re-arrangements of the cells, and changes in differential gene expression.