Production and Process Monitoring of 5-Aminolevulinic Acid (ALA) by Recombinant E. coli Ⅰ. Characteristics of ALA Production
Chung, S.Y.;Seo, K.H.;Han, K.A.;Cho, S.H.;Bak K.H.;Rhee, J.I.(Chonnam National University, Gwangju, Republic of Korea)E-mail:[email protected]
In this study the extracellular production of 5-aminolevulinic aicd (ALA) by recombinant E. coli BL2l (DE3) pLysS harboring the plasmid pFLS45 are investigated. Optimum concentrations of succinic acid and glycine for cell growth and ALA production were found to be 30 mM and 15 mM, respectively. Levulinic acid (LA) as an inhibitor of ALAD was added to the culture medium in the end of exponential cell growth phase and its optimum concentration was 30 mM. Growth of recombinant E. coli BL2l (DE3) pLysS [pFLS45] was largely dependent upon the pH value of culture medium. When the pH of culture medium was in the range of 6.0 and 6.5, high cell mass and ALA production were obtained. IPTG induction for the expression of the fusion gene did not enhance the production of ALA.
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