Phosphatase activity of the particular material in a polluted ecosystem: Toulon sea port
Phosphatase activity was estimated on particulate material resulting from filtration of sea water on 90, 5 and 0.25 μm membranes, from December 1999 to March 2000 in Toulon seaport. Para-nitrophenylphosphate (pNPP) dissolved in seawater was used as substrate. In these conditions, activities with low and high affinities were disclosed on each size class. The contribution of the 0.25-5 μm fraction was low, whereas the activity of the size class superior to 90 μm was elevated. Enzyme activities of fixed bacteria were characterized in the zooplanktonic and phytoplanktonic fractions. However, they cannot explain the totality of the measured activities in particular for zooplankton.