Nutritional control of copper uptake in the cyanobacterium Nostoc calcicola Bréb

Abstract

The kinetics of Cu uptake in nutritionally starved cells of the diazotrophic cyanobacterium Nostoc calcicola Bréb. have been compared with those in cells recovering from starvation. Unstarved cyanobacterial cells assimilated 97.0 nmol Cu mg-1 protein within 1 h when incubated in medium containing 40 μM Cu. Uptake was markedly inhibited in carbon-starved cells and, to a lesser extent, in cells starved of nitrogen or sulphur. The intracellular concentrations of protein and photopigments were markedly lower in cells starved of carbon, nitrogen, sulphur or phosphorus, whilst that of carbohydrate was lower in cells starved of carbon, sulphur or phosphorus, but almost doubled in cells starved of nitrogen. The ability to assimilate Cu was partially restored in cells after 72 h of recovery from phosphorus or sulphur deprivation, but showed little improvement during recovery from carbon or nitrogen starvation. A possible role of phosphorus in regulating Cu transport and accumulation is discussed. © 1991 Springer-Verlag.