Properties of mutants of Synechocystis sp. strain PCC 6803 lacking inorganic carbon sequestration systems

Abstract

A mutant (Δ5) of Synechocystis sp. strain PCC 6803 constructed by inactivating five inorganic carbon sequestration systems did not take up CO 2 or HCO3- and was unable to grow in air with or without glucose. The Δ4 mutant in which BicA is the only active inorganic carbon sequestration system showed low activity of HCO 3- uptake and grew under these conditions but more slowly than the wild-type strain. The Δ5 mutant required 1.7% CO2 to attain half the maximal growth rate. Electron transport activity of the mutants was strongly inhibited under high light intensities, with the Δ5 mutant more susceptible to high light than the Δ4 mutant. The results implicated the significance of carbon sequestration in dissipating excess light energy. © The Author 2008. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved.