旋扭山绿豆根瘤菌MXDI6菌株氢酶诱导表达

EXPRESSION OF HYDROGENASE SYSTEM IN STRAIN MXDI6 OF RHIZOBIUM (DESMODIUM INTORTUM)

摘要:

在自生异养条件下，旋扭山绿豆根瘤菌ＭＸＤＩ６菌株的氢酶诱导表达受气相、ｐＨ值、镍等因子影响：氢酶表达的最适氧浓度为４％，最适氢浓度为１５％，二氧化碳没有明显影响；氢酶表达的ｐＨ值以５．０—６．０为宜；０．５μｍｏｌ／ＬＮｉＣｌ２明显促进吸氢活性，但镍浓度大于１μｍｏｌ／Ｌ则抑制吸氢活性．

Abstract:

The capacity of inducing a H2-uptake hydrogenase under free-living heterotrophic condition was examined in strain MXDI6 of Rhizobium of Desmodium intortum, and the effect of some factors such as gas phase, pH values and nickel on the expression of hydrogenase in strain MXDI6 has been investigated. It has been found that: (1) The optimum concentration of O2 and H2 for hydrogenase expression of strain MXDI6 are 4% and 15% respectively, while carbon dioxide has no obvious effect. (2)Favourable pH values for expression of hydrogenase of strain MXDI6 are 5. 0-6. 0.(3) THe H2-up take activities in strain MXDI6 are enhanced markedly by adding a lower concentration (<1 μmol/L)of NiCl2, whereas it is inhibited by a higher concentration (> 1 μmol/L) of NiC12. When NiCl2 concentration is 0. 5 μmol/L, the H2-uptake activities are increased to 3. 4 times.