title: Enhanced enzyme activities of inclusion bodies of recombinant beta-galactosidase via the addition of inducer analog after L-arabinose induction in the araBAD promoter system of Escherichia coli.
abstract: We observed that an inclusion body (IB) of recombinant beta-galactosidase that was produced by the araBAD promoter system in Escherichia coli (E. coli) showed enzyme activity. In order to improve its activity, the lowering of the transcription rate of the beta-galactosidase structural gene was attempted through competition between an inducer (L-arabinose) and an inducer analog (D-fucose). In the deep-well microtiter plate culture and lab-scale fermentor culture, it was demonstrated that the addition of D-fucose caused an improvement in specific beta-galactosidase production, although beta-galactosidase was produced as an IB. In particular, the addition of D-fucose after induction led to an increase in the specific activity of beta-galactosidase IB. Finally, we confirmed that the addition of D-fucose after induction caused changes in the structure of beta-galactosidase IB, with higher enzyme activity. Based on these results, we expect that an improved enzyme IB will be used as a biocatalyst of the enzyme bioprocess, because an enzyme IB can be purified easily and has physical durability.
authors.affiliation: Division of Food and Biotechnology, Chungju National University, Chungju, Chungbuk 380-702, Korea. khjung@cjnu.ac.kr
authors.forename: Kyung-Hwan
authors.initials: KH
authors.lastname: Jung
mesh_terms: D001089:Arabinose / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D005643:Fucose / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D002479:Inclusion Bodies / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D001616:beta-Galactosidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D011994:Recombinant Proteins; D005643:Fucose; D001089:Arabinose; D001616:beta-Galactosidase