Properties of heterocysts isolated with colloidal silica

✍ Scribed by R. B. Peterson; R. H. Burris

• Book ID: 104770006
• Publisher: Springer
• Year: 1976
• Tongue: English
• Weight: 867 KB
• Volume: 108
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00425090

✦ Synopsis

A method is described for the isolation of heterocysts that are virtually free of contaminating cell debris after sonication of aerobically grown Anabaena 7120. Isolated heterocysts reduced acetylene in a light-dependent process in the absence of exogenously provided ATP; heterocysts supplied with ATP and Na2S2O4 reduced acetylene slowly in the dark but still showed a marked light activation. Nitrogenase activity was greatest in fractions containing intact heterocysts. Up to 13% of the activity of the intact filaments was accounted for in the isolated heterocyst preparation. Isolated heterocysts took up O2 in a light-independent process; O2 uptake with added NADP+ was enhanced by pyruvate, isocitrate and intermediates of the oxidative pentose pathway.