Evidence for microbiological manganese oxidation in the river Tamar Estuary, South West England

Abstract

Water samples from the Tamar Estuary oxidized manganese when supplemented with Mn 2+ (2 mgl −1). The rates of oxidation were depressed in the presence of various metabolic inhibitors. The effect of Mn 2+ and temperature on the rate of manganese oxidation suggested that a biological process was largely responsible for converting Mn 2+ to Mn 4+. Rates of manganese oxidation were much higher in freshwater (3·32 μgl −1 h −1 in water containing 30 mgl −1 of suspended matter) than in saline water (0·7 μgl −1 h −1 in water of salinity 32‰) containing the same amount of particulate matter. The rate of manganese oxidation was proportional to the particulate load (up to 100 mgl −1 particulates).