huxleyi grown for 6 days. The amount of cell used for analysis was corresponded to 5 μg Chl. Total and acid polysaccharide bands were visualized by “Stains-all” and “Alcian blue,” respectively Discussion According to the IPCC scenario, oceanic pH is estimated to decrease 0.5 U, namely to pH 7.7, by 2100 (IPCC 2007). In addition to the effects of atmospheric CO2 elevation, Salubrinal supplier acidification also can be seen at shallow coastal sites of volcanic CO2 vents. Along gradients of normal pH (8.1–8.2) to lowered pH (7.8–7.9, lowest 7.4–7.5), typical rocky shore communities with abundant calcareous organisms shifted

to communities lacking scleractinian corals with significant reductions in sea urchin and coralline algal abundance (Hall-Spencer et al. 2008). If it happens in the surface ocean, coccolithophores will also be damaged and such damage of the primary producers selleckchem in the ocean will change the composition

of the global phytoplankton community and ecosystems. There are various views on the effect that ocean acidification has on calcification of the coccolithophore E. huxleyi. Algal growth was reported to be suppressed by acidification in coccolithophores, e.g., the decrease in the specific growth rate of coccolithophores at pH values below 8.0 (Swift and Taylor 1966). Iglesias-Rodriguez et al. (2008) reported that promotion of the MCC950 purchase calcification would happen by increase of the CO2. In contrast, Riebesell et al. (2000) described that the formation of the coccoliths will be inhibited by acidification. In this study, we intended to compare the difference of acidification effect between

acidification by acid supply and the bubbling of elevated concentrations of CO2 in order to observe how coccolithophores respond potentially to acidification. The experimental conditions set in this study were not exactly the same as those expected in ocean acidification since seawater contained buffers to induce change in alkalinity. Cell density was also very high, and the rate of bubbling was not strong enough to get complete equilibration of inorganic carbons. Therefore, while the data we obtained are not directly applicable to the determination of the effect of ocean acidification on coccolithophores in the ocean, the data are still useful to predict how coccolithophores mafosfamide will respond to acidification physiologically. For this purpose, we analyzed the whole effect of acidification on cell growth, photosynthetic O2 evolution, photosystem’s activity, Ca-uptake, the productivity of polysaccharides of AP and NP and coccolith production in the most abundant, bloom-forming coccolithophore, E. huxleyi. When pH was simply decreased to 7.7 by acidification with HCl, the specific growth rate of E. huxleyi was diminished 31.2 % lower than that at pH 8.2 and they rapidly died within 1 day at pH 7.2 (Fig. 1a–d). In contrast, the acidification by CO2 enrichment by bubbling of 816 (lowest pH 7.