title: Photosynthetic Electron Transport in Spheroplasts and Thylakoid Membranes from the Thermophilic Blue-Green Alga, Synechococcus lividus.
abstract: Photosynthetic electron transport measurements and related analyses were carried out on spheroplasts and membrane fragments from the thermophilic blue-green alga, Synechococcus lividus . Intact spheroplasts that contained all of their phycobilin content required the presence of a lipophilic electron transport acceptor in the reaction medium for electron transport to proceed through Photosystem II. After gentle hypotonic shock, the resulting membrane fragments exhibited photosynthetic control through Photosystem II, with maximum electron transport activity occurring at 45 °C. Photosystem II electron transport was inhibited by DCMU. Analysis of membrane-bound cytochromes indicated the presence of the low potential cytochrome c549 , in addition to high and low potential cytochrome bs59, cytochrome f, and cytochrome b563. Membrane fragments exhibited cyclic photophosphorylation around Photosystem I and very slow rates of phosphorylation through Photosystem II. These results suggest that this organism is a promising system for the study of photosynthetic electron transport in cyano- phytes.
authors.affiliation: Bioenergetics Laboratory, 170 Acheson Hall, State University of New York at Buffalo, Buffalo, New York 14214 USA.
authors.forename: G
authors.initials: G
authors.lastname: Smutzer
authors.forename: J H
authors.initials: JH
authors.lastname: Wang