Enhancement of lysine production in recombinant Corynebacterium glutamicum through expression of Deinococcus radiodurans pprM and dr1558 genes

The expression of Deinococcus radiodurans dr1558 and pprM genes was examined for enhanced lysine production in recombinant Corynebacterium glutamicum. These genes are known to confer high tolerance to pH and osmotic shock in Escherichia coli. D. radiodurans dr1558 and pprM genes were expressed in C. glutamicum by using 6 synthetic promoters of different strengths, to evaluate the effect of expression efficiency on lysine production. Recombinant C. glutamicum expressing DR1558 under the L26 and I64 promoters showed higher lysine production than that expressing DR1558 under other promoters. Similarly, recombinant C. glutamicum expressing PprM under same promoters (L26 and I64) showed a higher increase in lysine production compared to that expressing PprM under other promoters. In the absence of CaCO₃ in the medium, the expression of DR1558 or PprM also increased lysine concentration in C. glutamicum depending on the promoter used. Together, these results suggest that genes involved in radiation tolerance in D. radiodurans can be used to enhance production of amino acids and their derivatives.