Photosynthetic Activities of Membrane Preparations of the Blue‐Green Alga Phormidium luridum

Abstract

Techniques were developed for the isolation of whole spheroplasts and membrane preparations from the blue-green alga P. luridum which are active in photosystem-II-sensitized and photosystem-I-sensitized electron-transport reactions and in photophosphorylation. Attention is called to the necessity of supplying Mn and phosphate throughout the preparation and procedures for obtaining active membranes. Selective washing of a proper membrane preparation is shown to remove a new protein factor termed protein factor 1, which restores the ability of the preparation to catalyze photosystem-I-sensitized reactions.