Formation and emission of monohalomethanes from marine algae

Methyl bromide (5.9 ng g wet algae(-1) hr(-1)) and methyl iodide (6.9 ng g wet algae(-1) hr(-1)) were produced by the microalga Pavlova gyrans, and methyl iodide (21.4 ng g wet algae hr(-1) for Papenfusiella kuromo and 4 ng g wet algae hr(-1) for Sargassum horneri) and a trace amount of methyl bromide by macroalgae. Methyl halides were synthesized from S-adenosyl-L-methionine (SAM) in cell-free extracts of P. gyrans, P. kuromo and S. horneri. This mechanism corresponded to the emission of methyl halides from the three algae in vivo. We have studied the optimal pH, and halide ion and methyl donor specificities of the novel enzyme from P. gyrans. (C) 1997 Elsevier Science Ltd.