Inorganic ion compositions in brown algae, with special reference to sulfuric acid ion accumulations

Cellular pH estimated from cell extract pH and the ion compositions of major inorganic ions (Na+, NH4+, K+, Mg2+, Ca2+,Cl-, Br-, N03-, S042-) were studied by ion chromatography in 61 species of 10 orders (Dictyotales, Desmarestiales, Ectocarpales, Chordariales, Scytosiphonales, Dictyosiphonales, Cutleriales, Sporochnales, Laminariales and Fucales) of Phaeophyceae. Three species in the order Dictyotales, Dictyopteris sp., Spatoglossum solierii (Chauv.) Kiitzing and umaria stipitata Tanaka et K. Nozawa, were newly found to be highly acidic (pH 0.6 and 1.4 within cells), in addition to previously reported dictyotalean species, Dictyopteris latiuscula (Okamura) Okamura, D. prolifera (Okamura) Okamura, D. repens (Okamura) B~rgesen and Spatoglossum crassum J. Tanaka. They all contained high concentrations of S042- perhaps within the vacuoles. Furthermore, Delamarea attanuata (Kjellman) Rosenvinge (Dictyosiphonales) and Thalassiophyllum clathrus (GmeI.) P. et R. (Laminariales) were shown to contain relatively high concentrations of S042- balanced by relatively high concentrations of Ca2+.