从作物根际分离的多粘芽孢杆菌固氮作用的研究

从作物根际分离的多粘芽孢杆菌固氮作用的研究 STUDIES ON NITROGEN FIXATION BY BACILLUS POLYMYXA ISOLATED FROM CROP RHIZOSPHERES 张高峡 Zhang Gaoxia 1 first-author 卢振祖 Lu Zhenzu 1 武汉大学生命科学学院 武汉大学生命科学学院 College of Life Science, Wuhan University College of Life Science, Wuhan University 用乙炔还原法，研究了从作物根际分离的５１株多粘芽孢杆菌的固氮作用，结果表明：２８株在有氧条件下培养能合成固氮酶并固氮，其中ＨＷ－１菌株固氮酶活性达７８．３×１０－６ｍｏｌＬ－１ｈ－１．该菌株固氮活性在对数生长后期（３６ｈ）最高，最适固氮培养条件是３５℃和ｐＨ８．０．该菌株在有５％氧气的条件下培养时，固氮活性最高，在初始培养和乙炔还原体系中分别注入５０％氧气仍能检测到乙炔还原活性．培养基中ＮＨ＋４阻遏该菌株固氮酶合成，但对已合成的固氮酶活性无影响． Nitrogenase activities of 51 Bacillus polymyxa strains were studied by acetylene reduction tests. These strains were isolated from crop rhizospheres. The result indicated that 28 strains could synthesize nitrogenase and fix nitrogen under aerobic culture, the nitrogenase activity of strain HW 1 was 78.3 ×10 -6 mol·L -1 ·h -1 （type strain DSM36 was 2.2×10 -6 mol·L -1 ·h -1 ）. The nitrogenase activity of strain HW 1 was the highest in late exponential phase （36 h）, the optimal conditions of nitrogease activty were 35℃、pH 8.5. The highest nitrogenase activity of strain HW 1 was measured under 5% O 2 culture. The nitrogenase activity could detected by injecting 50% O 2 not only in the beginning of culture but also in acetylene reduction system. The nitrogenase protein synthesis was repressed by ammonia in growth medium, but in acetylene reduction system no effect of ammonia on nitrogenase activity was observed. 多粘芽孢杆菌 固氮作用 乙炔还原 B. polymyxa nitrogen fixation acetylene reduction S154.351 1998-06-01 2021-04-01 6