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The whole-cell immobilization of D-hydantoinase-engineered Escherichia coli for D-CpHPG biosynthesis
Jin, Yuan-yuan; Li, Ya-dong; Sun, Wan; Fan, Shuai; Feng, Xiao-zhou; Wang, Kang-you; He, Wei-qing & Yang, Zhao-yong
Abstract
Background: D-Hydroxyphenylglycine is considered to be an important chiral molecular building-block of
antibiotic reagents such as pesticides, and β-lactam antibiotics. The process of its production is catalyzed by
D-hydantoinase and D-carbamoylase in a two-step enzyme reaction. How to enhance the catalytic potential of
the two enzymes is valuable for industrial application. In this investigation, an Escherichia coli strain genetically
engineered with D-hydantoinase was immobilized by calcium alginate with certain adjuncts to evaluate the
optimal condition for the biosynthesis of D-carbamoyl-p-hydroxyphenylglycine (D-CpHPG), the compound
further be converted to D-hydroxyphenylglycine (D-HPG) by carbamoylase.
Result: The optimal medium to produce D-CpHPG by whole-cell immobilization was a modified Luria-Bertani
(LB) added with 3.0% (W/V) alginate, 1.5% (W/V) diatomite, 0.05% (W/V) CaCl2 and 1.00 mM MnCl2. The
optimized diameter of immobilized beads for the whole-cell biosynthesis here was 2.60 mm. The maximized
production rates of D-CpHPG were up to 76%, and the immobilized beads could be reused for 12 batches.
Conclusions: This investigation not only provides an effective procedure for biological production of D-CpHPG, but
gives an insight into the whole-cell immobilization technology.
© 2016 Pontificia Universidad Católica de Valparaíso. Production and hosting by Elsevier B.V. All rights reserved.
Keywords
Calcium alginate; D-Carbamoyl-p-hydroxyphenylglycine; D-Hydantoinase; D-Hydroxyphenylglycine; Immobilization; Whole cell
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