Osmotic shock-induced release of low molecular weight metabolites from free-living and immobilized cyanobacteria

Abstract

A procedure is described for the release of low molecular weight carbohydrates and free amino acids from the unicellular cyanobacteria Synechocystis PCC6714 and Synechococcus PCC6311. Metabolite release was induced by rapid transfer of free-living or immobilized cells grown in a medium containing 490 mol m −3 NaCl to a freshwater-based medium (BG-11); up to 50% of the low molecular weight carbohydrates and 73% of the intracellular free amino acids were released within 2 min. Cells of Synechocystis PCC6714 were subjected to repeated osmotic shock, with no evidence of long-term damage to the cells after three cycles of metabolite release over a 48 h period. Because this procedure does not involve harvesting or death of the cells, it may prove to be a useful means of recovering metabolites from viable microorganisms.