HYDROGENASE ACTIVITY IN SCENEDESMUS D3 CULTURED IN A MEDIUM CONTAINING CARROT EXTRACT1

Abstract

Scenedesmus species D₃ (GAFFRON's strain) cultured in a medium containing boiled extract of carrot root was found to be able to absorb molecular hydrogen in the presence of MB or nitrite as a hydrogen acceptor in the dark under H₂-atmosphere and also to carry out photoreduction in the presence of CO₂ and the oxyhydrogen reaction in the presence of oxygen without the dark period of adaptation which was required for the appearance of these activities in the cells grown in an inorganic medium. At the light intensity exceeded a certain threshold, transition from photoreduction to normal photosynthesis occurred, but the absorption of hydrogen by the cells cultured in a carrot medium was resumed upon return to low light intensity.