Nitrogen Metabolism in Scenedesmus as Affected by Environmental Changes.

In recent years investigations into the physiology of green algae have been stimulated by a recognition of their possible commercial use (6) in addition to their common acceptance as research tools for certain fundamental problems. These physiological studies have shown that green algae have a high nitrogen content. A correspondingly high protein content has been inferred (28). Relatively little attention has been given to the utilization of the absorbed nitrogen or to changes in the nitrogen fractions of cells subjected to a changing environment. Comparisons with higher plants (7, 30) have not been possible because of the necessity for large and frequent samples of algae required for reliable analytical determinations. The development of a mass culture technique (14, 16) has made this feasible. This paper reports an extensive study of the nitrogen metabolism of a representative, fresh-wN-ater, green alga, Scenedesmus obliquus (Turp.) Kiutz., grown in mass culture. Changes in the content of the major nitrogen fractions are correlated with modifications in the environment, and a basis is established for future detailed examination of specific pathways of nitrogen metabolism.