Growth of Scenedesmus obliquus in relation to the supply of iron.

Equal amounts of iron in the form of iron citrate or Fe-EDTA were added to the mineral media. The effect of the two salts upon cell-, substance-and chlorophyll-production of Scenedesmus obliquus cultivated in light-dark-regimes of 15:9 hours was studied.In bubbling cultures at 75 000 Lux the number of cells and the dry substance increased by a factor of about 16-19 with Fe-EDTA and by a factor of 10-12 with iron citrate. With both salts it was possible to get a production of daughter cells twice within one light-dark-cycle of 24 hours.The chlorophyll content of cells and substance cultivated in Fe-EDTA-medium was smaller than that of those cultivated in iron citrate-medium. The possible relations between the amount of chlorphyll and the production of substance are discussed.