The changes in growth and biochemical composition of Porphyridium cruentum cultures

In this study, the growth and accumulation of polysaccharides in Porphyridium cruentum at different light (50, 100 and 150 µmol photon m-2 s-1) and temperatures (18, 22 and 26 ºC) in small volume cultures (1 L), in different light path lengths (17,5, 23,0 and 27,5 cm), in polyethylene bags (20 L) and in open ponds in large volume cultures (1000 L) were studied. The result of the studies carried out showed that the best growth was achieved at 22 ºC and 150 µmol photon m-2 s-1 on the 16th day. Accordingly, the highest cell count was found to be 23,9 x 106 cells mL-1 and the dry weight was found to be 1,75 g L-1. As for the different light path lengths, the highest cell count was found in 17,5 cm (4,2 x 106 cells mL-1). The highest polysaccharide content in the cells was found on the 12th day at 18 ºC and 50 µmol photon m-2 s-1 to be 45 % of the dry weight. In the trials carried out in polyethylene bags, the cell count was 6,3 x 106 cells mL-1 on the 15th day at 100 µmol photon m-2 s-1. As for pond cultures, the cells were increased during the first 6 days (0,9 x 106 cells mL-1), and the cells started to decrease in the following days.As a result, it was seen that the both of the growth and the rate of polysaccharide production were in general increased by the increasing temperature and light. In addition, it was seen that starting with higher cell concentrations in the experiments to be done outdoors under strong sun light was important.Keywords: Porphyridium cruentum, polysaccharide, growth, polyethylene bags, pond