Increased biological hydrogen production by deletion of hydrogen-uptake system in photosynthetic bacteria.
Hydrogenases are the key enzymes for the biological hydrogen production, which can be classified as H(2)-uptake hydrogenase and H(2)-production hydrogenase. The genes encoding a membrane-bound [NiFe]-hydrogenase (MBH), which is mainly responsible for hydrogen uptake, from the photosynthetic bacterium Allochromatium vinosum was cloned and sequenced. It consist of two structural genes (hydS, hydL) and two intergenic genes (isp1, isp2), which are therefore organized as hydS-isp1-isp2-hydL. This is different from the arrangement of other typical hydrogenase gene clusters. A deletion mutant-strain PhihydSL, lacking isp1, isp2, partial hydS and hydL genes, was constructed by marker-exchange mutagenesis. Under dark fermentative conditions, the hydrogen production yield by this mutant increased by 62%. The result suggests that the disruption of MBH could greatly improve the hydrogen production in the cells by decreasing the hydrogen uptake.
Liang
Yi
Y
School of Life Sciences, School of Energy Research, Xiamen University, Xiamen 361005, PR China.
Wu
Xiaobing
X
Gan
Lihui
L
Xu
Huijuan
H
Hu
Zhong
Z
Long
Minnan
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002841:Chromatiaceae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010788:Photosynthesis; D016415:Sequence Alignment; D017384:Sequence Deletion
D001426:Bacterial Proteins; D006859:Hydrogen; C043296:nickel-iron hydrogenase; D006864:Hydrogenase