Cloning of Enterobacter aerogenes fhlA gene and overexpression of hydrogen production
产气肠杆菌fhlA基因克隆、表达及重组菌株产氢量

Abstract: Objective] We amplified and overexpressed the FHL activator (fhlA) in E. aerogenes ATCC13408 to enhance hydrogen production. Methods] By using universal primers and genome walking, we cloned the full open reading frame (ORF) of fhlA gene. We inserted it into the glutathion S-transferase (GST) fusion expression vector pGEX-4T-2-Cat, and transformed the recombinant plasmid into E. aerogenes ATCC13408 via electroporation for expression. Then we measured the hydrogen production of the recombinant strain in a batch culture. Results] We found that the ORF of fhlA was 2073 base pair in length, potential to encode a 690 amino acid peptide (GenBank accession GU188474). The FhlA protein from E. aerogenes ATCC13408 shared high amino acid identities with those from other bacterial species. By using SDS-PAGE and Western blot analysis, we confirmed that the fhlA gene had successfully expressed in the strain. The hydrogen yield of the recombinant strain was increased from 1.23 to 1.48 mol H2/mol glucose. Conclusion] Enhancement of hydrogen productivity was attained under anaerobic conditions with the recombinant strain.