The effect of physical conditions of cultivation on the respiratory metabolism of algae

An investigation was made as to whether the cultivation conditions of algae affect their respiratory metabolism. Chlorella pyrenoidosa (82), Scenedesmus obliquus (125) and Euglena gracilis (259) were cultivated both in a static and shaken culture. It was found that shaking considerably affects the respiratory metabolism of algae. The shaken cultures, in contrast to the static ones, display a higher O2 consumption and have mostly a different RQ. It is possible that the differences observed are due to accelerated development and ageing of the shaken cultures. It thus appears that shaking is an important factor in cultivation which must be taken into account during growth of experimental material. The values of RQ found here to be about 1–3 point to the fact that anaerobic glycolytic processes can proceed even under fully aerobic conditions. The culture of Scenedesmus obliquus (125) appears to have a less adaptable metabolism and does not respond to environmental changes as readily as Euglena gracilis or Chlorella pyrenoidosa.