EFFECTS OF CO2 CONCENTRATIONS ON GROWTH IN THE COCCOLITHOPHORIDS (HAPTOPHYTA)

Transformation CO2 into cell organic matter and cell CaCO3 (coccoliths ) by coccolithophorids is one of the useful ways to remove CO2 indirec tly in fluegas generated at thermal power plants in addition to the re duction of atmospheric CO2. To examine the effects of 100% CO2 on the growth, determined as cell organic carbon and cell inorganic carbon (c occoliths), in the two coccolithophorids species, Pleurochrysis carter ae and Pleurochrysis haptonemofera, the cultures with race way method were carried out by maintaining pH with intermittent supply of 100% CO 2. Furthermore, the results of the growth under 100% CO2 were compared with that of the growth under atmospheric CO2 concentration (0.04% CO 2). As a result, the growth rates of both species were increased remar kably by supply of 100% CO2, and the growth rates and the maximum yiel ds with 100% CO2 of P. haptonemofera were 1.5 times and 2 times higher than those of P. carterae, respectively.