Sensitivity of Nostoc commune UTEX 584 (Cyanobacteria) to water stress

Abstract

Cells of Nostoc commune UTEX 584 from liquid cultures expressed an upshift in nitrogenase activity when immobilised on inert supports and exposed to matric water potentials between -1.10 and -99.5 MPa. Cells incubated at 0.10 MPa (aw=c 1.0) maintained increased activity for at least 48 h following immobilization. At water potentials below -23.1 MPa (aw=0.85), the upshift was transitory. Nitrogenase activity decreased rapidly when immobilised cells were incubated at lower values of ψm.