The Normal and Induced Occurrence of Cyanophycin Inclusion Bodies in Several Blue‐green Algae¹

Multi‐L‐arginyl‐poly(L‐aspartic acid) [arg‐poly(asp)], the polypeptide component of the cyanophycin inclusion body, is found in cells of many blue‐green algae. Formation of this material can be induced by a variety of treatments including the addition of excess nitrogen‐containing compounds, the addition of specific inhibitors of macromolecular synthesis, and the exclusion of sulfur or phosphorus. Knowledge of the conditions that induce the synthesis of this polypeptide has made possible an ultrastructural survey to determine the presence and cellular location of cyanophycin bodies in a variety of cyanobacteria. Data presented show that certain strains of the unicellular genus Synechococcus Nägeli do not contain arg‐poly(asp) under environmental conditions that markedly increase the level of such material in other cyanobacteria. In addition many strains show spatial localization of the cyanophycin bodies under normal growth conditions, and moreover the normal pattern is retained even when massive synthesis of arg‐poly(asp) is induced. Finally there is no evidence that these inclusion bodies occur in certain beggiatoan gliding bacteria.