Comparison of stroma- and pyrenoid-starch in Chlorella grown under low and high CO sub(2)conditions

• Published in: Journal of plant research Vol. 119; p. 91
• Main Authors: Izumo, A, Fujiwara, S, Satoh, A, Fujita, N, Nakamura, Y, Tsuzuki, M
• Format: Journal Article
• Language: English
• Published: 01.12.2006
• Subjects: Chlorella
• ISSN: 0918-9440

Green algae have starch, like higher plants, which consists of amylose and amylopectin. However, components of pyrenoid starch have not been analyzed yet separatedly from stroma starch. Therefore we examined a culture condition with Chlorella and tried to separate pyrenoid and stroma starch. A starch content per a cell was low with an early stage of the culture, and then increased during the culture in 3% CO sub(2). The cells contained only stroma starch due to the poor development of pyrenoid. When the cell in the early stage of the culture was transferred to ordinary air, each cell showed a developed pyrenoid in 12 hrs, and contains mostly pyrenoid starch which did not include the stroma starch. As a result, stroma starch and pyrenoid starch had both amylose and amylopectin, but a ratio of amylose was higher in the latter. A gelatinization temperature characteristic was different in the two. In addition, starch content increased during the culture in low CO sub(2) condition where the cells had a high content of stroma starch. Some characteristics of stroma starch were suggested to be affected by CO sub(2) during the culture.