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比较了用海藻酸钠、琼脂、聚丙烯酰胺、K-卡拉胶和明胶包埋法及DEAE-纤维素吸附法固定化的固氮菌的乙炔还原活性,表明海藻酸钠包埋的菌体固氮酶的活性最高、持续时间也最长,琼脂包埋的次之.菌体悬液(10~(20)/ml)与海藻酸钠(4％)的配比以1:5为佳。其固定化菌体的乙炔还原活性的最适pH为7.5,最适温度为32℃,Km为20μM,活化能为10.29kcal/mol,Vmax为14.2μM.丙二酸,2,4-二硝基酚,叠氮化钠,磺基水杨酸,硫酸铵,硝酸钾,高浓度亚硝酸钠有抑制作用,而低浓度亚硝酸钠有刺激作用,CO_2对其乙炔还原和放氢有抑制作用,CO对其放氢无抑制作用.其乙炔还原的最适氧分压为10kPa.
Acetylene reduction activity of azotobacter immobilized with sodium alginate, agar, polyacrylamide, K-carrageenan and gelatin and DEAE-cellulose adsorption was compared, indicating that alginate-embedded bacterial nitrogenase The highest activity, the longest duration, followed by agar embedding.Mice suspension (10 ~ (20) / ml) and sodium alginate (4%) ratio of 1: 5 is better. The optimum pH of the acetylene reduction activity of the immobilized cells was 7.5, the optimum temperature was 32 ℃, the Km was 20μM, the activation energy was 10.29kcal / mol and the Vmax was 14.2μM. Malonic acid, 2,4-dinitro Phenol, sodium azide, sulfosalicylic acid, ammonium sulfate, potassium nitrate, high concentrations of sodium nitrite inhibition, and low concentrations of sodium nitrite stimulate the role of carbon dioxide on its acetylene reduction and hydrogen release inhibition , CO had no inhibitory effect on the release of hydrogen, and the optimum partial pressure of oxygen for the reduction of acetylene was 10kPa.