| 초록 |
As other microbial production process, the performance of biocatalyst often determines the success of dark fermentative hydrogen (H2) production. However, it is not simple to determine which microorganism is suitable for H2 production process. Here, we compared 4 different Enterobacteriacea (Enterobacter aerogenes, Citrobacter amalonaticus Y19, Escherichia coli K-12 and Escherichia coli DKJ135) for its capability of H2 production. The comparison showed that H2 production activities of microorganisms were not much different except of wild type E. coli K-12 from format and modification of gene expression of fhlA (encoding activator of formate-hydrogen lyase(FHL)) could affect to improvement of H2 production activity. Therefore, by modifying the expression of relevant genes including fhlA, improvement of H2 production activities was attempted. H2 production activity was significantly increased more than 3-fold by deleting both hycA (encoding repressor of FHL) and iscR (iron-sulfur cluster regulator) and overexpressing fhlA. In addition, we confirmed the high volumetric H2 production activity (2.4 L/L/h) from formate using mutant strain of E. coli SH5. |
