EFFECT OF PHOSPHORUS STARVATION ON GROWTH, PHOTOSYNTHESIS AND SOME METABOLIC PROCESSES IN THE UNICELLULAR GREEN-ALGA CHLORELLA-KESSLERI

The effect of phosphorus starvation on growth and several physiologica l parameters of the unicellular green alga, Chlorella kessleri have be en examined. Increase in dry weight production and decrease in optical density of the algal suspension, chlorophyll concentration, photosynt hetic activity (measured as oxygen evolution) and dark respiration are dominating features for phosphorus starvation. The lipid content of t he alga was separated into five classes depending on their mobilities on thin layer chromatography. The five classes identified are: Digalac tosyl diacylglycerol (DGDG), monogalactosyl diacylglycerol (MGDG), pho sphatidyl choline (PC), phosphatidyl glycerol (PG), and sulfoquinovosy l diacylglycerol (SQDG). The differences in fatty acid composition of the total lipids and each individual lipid class was estimated by gas liquid chromatography. The phosphorus content of total lipids of Pi-st arved and nutrient sufficient cells showed a large difference in the e xponential and stationary growth phase.