铁和镍对光合细菌生长和产氢的影响

Effects of Iron and Nickel on Hydrogen Photoevolution, Cell Growth, and Photosynthetic Pigment of Photosynthetic Bacteria

基于金属元素在生物体功能发挥中的作用以及它们参与光合细菌光合放氢的重要性 ,着重进行了铁和镍对沼泽红假单胞菌 (Rhodopseudomonaspalustris)Z菌株和一株红杆菌(Rhodobactersp.)细胞生长、光合放氢和光合色素合成影响的研究。结果表明 ,高浓度Fe3+可显著提高两菌株光放氢能力和生物合成能力 ,最适浓度的Fe3+可使其产氢能力分别达对照组的 1 32倍和 2 8倍 ,产氢得率分别为 360 6mL g和 385 9mL g,生物量分别为对照组的1 42倍和 1 5 4倍。 9μmol LNi2 +的添加可使两菌株产氢能力分别达对照组的 1 48倍和 1 96倍 ,产氢得率分别为 42 9 7mL g和 45 6 3mL g。而当Ni2 +浓度为 1 2 μmol L时 ,两菌株的产氢活性受到不同程度的抑制 ,产氢得率分别降低 46 7%和 1 9 4%。在铁浓度相同时 ,添加 6μmol LNi2 +能明显促进两菌株的生长。而当Ni2 +浓度大于 6μmol L时 ,细胞生长受到抑制。Fe3+和Ni2 +对Rhodobactersp .菌株类胡萝卜色素有显著影响。研究结果显示 ,42 6nm色素峰随铁浓度的增加和镍的添加而消失 ,同时 。

The influences of metal ions of Fe 3+ and Ni 2+ on H 2 productivity, cell growth and photosynthetic pigment in Rhodopseudomonas palustris Z strain and Rhodobacter sp. were investigated. The results showed that the addition of the optimal concentrations of Fe 3+ and Ni 2+ to the medium could enhance H 2 productivity and cell growth remarkably. Metal ions of Fe 3+ and Ni 2+ had strong influence on photosynthetic pigments. The optimal concentrations of Fe 3+ and Ni 2+ for H 2 production in R.palustris Z strain lay in the range of 150 ～ 200 μmol/L and 3 ～ 9 μmol/L, the highest H 2 yield was 360 6 mL/g and 429 7 mL/g, which was 1 32 fold and 1 48 fold comparing with the control, respectively. The optimal concentrations of Fe 3+ and Ni 2+ for cell growth were 100 μmol/L and 6 μmol/L, respectively. For Rhodobacter sp., the optimal concentrations of Fe 3+ and Ni 2+ for H 2 evolution were 150 μmol/L and 9 μmol/L, the maximal H 2 yield of 385 9 mL/g and 456 3 mL/g were obtained, which was 2 8 fold and 1 96 fold comparing with the control, respectively. Cell growth could be stimulated by adding 150 μmol/L of Fe 3+ and 6 μmol/L of Ni 2+ to medium, which was 1 54 fold and 1 39 fold comparing with the control. The relationship between H 2 productivity and the appearance or disappearance of 426 nm absorption peak by adding higher concentration of Fe 3+ and Ni 2+ to the medium revealed that the photosynthetic pigment of 426nm may plays an important role in H 2 photoevolution.