Nickel regulation of photoautotrophy in a cyanobacterium

Abstract

Ni inhibited photoautotrophic growth, nitrogenase activity, oxygenic photosynthesis (O2-evolution, 14CO2-uptake) and respiratory O2-uptake in the diazotrophic cyanobacterium, Nostoc muscorum. 14CO2-uptake was more sensitive to Ni compared to nitrogenase activity, O2evolution or respiratory O2-uptake. Lower Ni concentrations (1 μ.M and 5 μM) stimulated N2ase as well as RuBPcase (ribulose bisphosphate carboxylase) activity. It is proposed that Ni inhibition is mainly through the regulation of RuBPcase activity in the cyanobacterium. © 1990 Kluwer Academic Publishers.