Abstract
The glr gene, which encodes glutamate racemase involved in the conversion of l-glutamic acid to its D-isomer, was cloned and expressed in Bacillus licheniformis WX-02. Overexpression of the glr gene not only increased the production of poly-γ-glutamic acid (γ-PGA) by 22.5% but also increased the proportion of d-glutamate in γ-PGA from 77 to 85%. The activity of glutamate racemase was higher than in the original strain throughout cultivation. This is the first report that overexpression of the glr gene could enhance the l- and d-glutamate conversion in B. licheniformis WX-02 and increase the proportion of d-glutamate in γ-PGA and the yield of γ-PGA.
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Acknowledgments
This work was supported by the Program for New Century Excellent Talents in University of China (no. NCET-07-0341) and the National High-Tech Research and Development Program of China (no. 2008AA10Z317).
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Jiang, F., Qi, G., Ji, Z. et al. Expression of glr gene encoding glutamate racemase in Bacillus licheniformis WX-02 and its regulatory effects on synthesis of poly-γ-glutamic acid. Biotechnol Lett 33, 1837–1840 (2011). https://doi.org/10.1007/s10529-011-0631-7
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DOI: https://doi.org/10.1007/s10529-011-0631-7