Algae. 1991; 6(2): 203-212.

A physio-biochemical study on the Synthesis and Degradation of Poly-β-hydroxybutyrate and Polyphosphate in a Blue-green Alga chlorogloea fritschii

Ki Sung Lee, Soon Ae Yoo, Young Sik Park

Department of Biology, Pai Chai University, Department of Biology, Hanyang University

The blue-green alga Chlorogloea fritschii was cultured under various conditions (Pi-free or sufficient and /or different light/dark photoperiod) in order to elucidate the physio-biochemical interrelationship between synthesis and degradation of poly-β-hydroxybutyrate and polyphosphate body. Under Pi-starved condition, the activity of phosphatase was derepressed, whereas under Pi-sufficient condition it was repressed. The major phospholipid components of C. fritschii were analyzed as phosphatidyl ethanolamine, cardiolipin, phosphatidyl glycerol, and lysophosphatidyl ethanolamine. The change of their amounts was marked according to the culture conditions. Their synthesis and intracellular conversion were active in vigorous cells or dividing cells. The components of photosynthetic pigments i. e. carotenoid, phycocyanin, and phycoerythrin increased in Pi-free culture, but they decreased in Pi-sufficient culture. The longer culture of C. fritschii under Pi-free condition, the lower the energy charge, and both the uridylate pool and cytidylate pool increased.

Keywords : phosphatase, phosphate stress, photosynthetic pigment, energy charge, optimal condition for PHB synthesis