Effect of dissolved oxygen on nitrite reductase fermentation by Bacillus megaterium MPF-906

Bacillus megaterium MPF-906 was cultivated by shaking culture with static intervals.The effects of different static intervals on nitrite reductase(NiR) production were investigated.The relationship between the growth of B.megaterium MPF-906,the consumption of substrate and the activity of nitrite reductase was analyzed.The results showed that when there was a 60min static interval following every 2h shaking in the initial 12h of fermentation,the highest NiR activity was appeared at 20h.Under above conditions,the biomass of B.megaterium MPF-906,the degradation of nitrite and the consumption of glucose were all lower than control under shaking flask cultivation,but the NiR activity at 20h was 98.7U/ml and 103.4% higher than control.