Preliminary Characterization of a NADPH Dependent Chromate Reductase from Trichoderma pseudokoningii

Intracellular chromate reductase enzyme extracted from a chromium tolerant strain Trichoderma pseudokoningii was partially purified by ultrafiltration and gel filtration chromatography. The purified fraction showed highest reducing activity in presence of 1% (w/v) hexavalent Chromium. NADPH at a conentration of 2 mM was found to act as electron donor in the reduction reaction. The intracellular chromate reductase was found to have an optimum pH and temperature of 7.4 and 70 °C respectively. The enhancement of reductase activity in presence of exogenous thiols indicated the presence of thiols at active site.