Algae. 1989; 4(1): 63-67.

Studies on Nitrate Reductase in Ulva pertusa 1. In vivo Nitrate Reductase Activity

Bang-Ook Jun, Dae-Hwan Kim

Department of Biology, Kangreung National University

The applicability of in vivo nitrate reductase assay and effects of several factors influencing enzyme induction in Ulva pertusa were investigated. Four percent propanol was most suitable for the in vivo assay, and starvation of 3 days are prerequisite for induction study. For the induction of nitrate reductase both light and nitrate were required. Glucose could not substitute for light. DCMU completely inhibited, whereas 2,4-dinitrophenol, cyanide and azide hardly affected enzyme induction. These results suggest the possibility that reducing power required for the induction of nitrate reductase is NADPH. Tungstate inhibited increment of nitrate reductase activity probably by competition with molybdate required for enzyme activity. Ammonium, ion and cycloheximide repressed enzyme induction.

Keywords : In vivo assay, nitrate reductase, Ulva pertusa.