Abstract
The effects of Fe ion on lipase activity of two kinds of Rhizopus japonicus sp. were studied. The enzyme activities with Fe and without Fe were compared in various pH values. In sample A, almost same activities were observed at pH 3.2, 4.0, 5.0 and 6.0, while in sample B, the activity was low at pH 3.2 without Fe ion and increased in proportion to pH values. Activity was almost same at pH 4.0, 5.0 and 6.0, but increased at pH 3.2 with Fe and almost same at pH 3.2, 4.0, 5.0 and 6.0. It was found that samples A and B had the same components, but the different molecular states in protein as tested by the electrophoresis method and molecular filtering. In low pH values, sample B was in higher molecular state than sample A. However, in the presence of Fe ion, it changed to the low molecular state. It was considered that the lipase activity accelerated in the presence of Fe ion influenced the molecular state.
