摘要
A submerged culture technique for Magneto-spirillum gryphiswaldense under the nitrogen-fixing condition (microaerobic and N-limited) was set up. In N-limited medium with Na-lactate as a sole carbon source, the optical density (A600 nm) and activity of nitrogen fixation of cells were 1.3 and 217 nmol of ethylene produced per hour per A600nm respectively within 21 h by three times of feeds. The pH and temperature were controlled at 7.2 and 30℃ respectively, and the oxygen concentration was controlled by sparging with N2 containing 0.4%-0.8% of O2. The activity of nitrogen fixation of cells was obviously inhibited by oxygen and ammonium. It indicated that the posttranslational regulation of nitrogenase existed in M. gryphiswaldense.
A submerged culture technique for Magneto-spirillum gryphiswaldense under the nitrogen-fixing condition (microaerobic and N-limited) was set up. In N-limited medium with Na-lactate as a sole carbon source, the optical density (A600 nm) and activity of nitrogen fixation of cells were 1.3 and 217 nmol of ethylene produced per hour per A600nm respectively within 21 h by three times of feeds. The pH and temperature were controlled at 7.2 and 30℃ respectively, and the oxygen concentration was controlled by sparging with N2 containing 0.4%-0.8% of O2. The activity of nitrogen fixation of cells was obviously inhibited by oxygen and ammonium. It indicated that the posttranslational regulation of nitrogenase existed in M. gryphiswaldense.
基金
This work was supported by the National Natural Science Foundation of China (Grant No. 30170012)
the National Key Basic Research Development Program (Grant No. 001CB 108904).
