Disruption of the uptake hydrogenase gene, but not of the bidirectional hydrogenase gene, leads to enhanced photobiological hydrogen production by the nitrogen-fixing cyanobacterium Anabaena sp PCC 7120
Disruption of the uptake hydrogenase gene, but not of the bidirectional hydrogenase gene, leads to enhanced photobiological hydrogen production by the nitrogen-fixing cyanobacterium Anabaena sp PCC 7120
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DOI：
10.1007/s00253-002-0934-7
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发表时间：
2002-04-01
影响因子：
5
通讯作者：
Sakurai, H
中科院分区：
文献类型：
--
作者：
Masukawa, H;Mochimaru, M;Sakurai, H
研究了氢酶基因缺失对异囊固氮蓝藻光合产氢的影响。我们从鱼腥藻PCC 7120构建了三种氢化酶突变体：hupL（-）（摄取氢化酶缺陷）、hoxH（-）（双向氢化酶缺陷）和hupL（-/）hoxH（-）（两种基因都缺陷）。在最佳条件下，hupL（-）突变体产生H-2的速率是野生型的4至7倍。hoxH（-）突变体产生的H-2量显著低于野生型，固氮酶活性略低于野生型。hupL（-）/hoxH（-）突变体的H-2产量略低于但几乎等于hupL（-）突变体的H-2产量。在氩气氛下，光化可见光强度为10 W/m2（PAR）时，hupL（-）突变体在其最高H-2产生阶段的光能转化效率为1.2%。这些结果表明，hupL基因的缺失可以用作进一步改善基于固氮酶的光生物H-2生产系统中的H-2生产的来源。
In order to determine the effects of the deletion of hydrogenase genes on nitrogenase-based photobiological H-2 productivity by heterocystous N-2-fixing cyanobacteria. we have constructed three hydrogenase mutants from Anabaena sp. PCC 7120: hupL(-) (deficient in the uptake hydrogenase), hoxH(-) (deficient in the bidirectional hydrogenase), and hupL(-/)hoxH(-) (deficient in both genes). The hupL(-) mutant produced H-2 at a rate four to seven times that of the wild-type under optimal conditions. The hoxH(-) Mutant produced significantly lower amounts of H-2 and had slightly lower nitrogenase activity than wildtype. H-2 production by the hupL(-)/hoxH(-) mutant was slightly lower than, but almost equal to, that of the hupL(-) mutant. The efficiency of light energy conversion to H-2 by the hupL(-) mutant at its highest H-2 production stage was 1.2% at an actinic visible light intensity of 10 W/m(2) (PAR) under argon atmosphere. These results indicate that deletion of the hupL gene could be employed as a source for further improvement of H-2 production in a nitrogenase-based photobiological H-2 production system.