Metabolic activities of isolated heterocysts of the blue-green alga Anabaena cylindrica.

Abstract

KNOWLEDGE of the nature of the heterocysts of blue-green algae has been limited by the lack of suitable techniques for investigation of the physiology and biochemistry of these puzzling structures. The association of the presence of heterocysts with the ability to fix free nitrogen and the findings1,2 that ammonia suppresses both nitrogen fixation and heterocyst formation have led to the suspicion that these cells might be involved in the nitrogen-fixation process. In this communication we report a successful technique of ‘differential cell disruption’ for the isolation of heterocysts of Anabaena cylindrica. We also present the first results concerning the metabolic activities of isolated heterocysts.