Green macroalga Ulva lactuca Linnaeus and red macroalga Ahnfeltiopsis flabelliformis (Harvey) Masuda were cultured in CO2-enriched seawater (including 5-10 times CO2 than normal seawater) (CSW) and normal seawater (NSW) for a week, respectively. We compared daily growth rate (DGR), morphology and intracellular soluble proteins between CSW- and NSW-cultured thalli. DGR of CSW-cultured thalli was higher than NSW-cultured thalli in both U. lactuca (1.2 times) and A. flabelliformis (1.7 times). Morphology of A. flabelliformis in CSW-cultured thalli had much branchlets issued from lateral portion of branches than that in NSW-cultured thalli. In comparison of intracellular soluble protein, we detected specific protein in CSW-cultured thalli in both U. lactuca (33 kDa) and A. flabelliformis (60 kDa) by bi-dimensional electrophoresis.
