All nine species of marine phytoplankton tested (a cyanobacterium: Synechococcus sp., three diatoms: Chaetoceros simplex, Thalassiosira oceanica and Skeletonema costatum, two prymnesiophytes: Pleurochrysis carterae and Isochrysis galbana, a prasinophyte: Tetraselmis sp., a green alga: Dunaliella tertiolecta, and a dinoflagellate: Amphidinium carterae) were able to decompose hydrogen peroxide in the dark. Since these phytoplankton species can be found widely in a variety of marine sub-environments, this indicates that the dark decomposition of hydrogen peroxide by phytoplankton is a general phenomenon in the oceans. The decomposition rates were first order with respect to the concentration of hydrogen peroxide and biomass. The second-order rate constants... |