Large-scale engineering of the Corynebacterium glutamicum genome.
Appl. Environ. Microbiol.  71: 3369-3372. 2005.
N. Suzuki, S. Okayama, H. Nonaka, Y. Tsuge, M. Inui and H. Yukawa.

The engineering of Corynebacterium glutamicum is important forenhanced production of biochemicals. To construct an improvedC. glutamicum genome, we developed a precise genome excisionmethod based on the Cre/loxP recombination system and successfullydeleted 11 distinct genomic regions identified by comparativeanalysis of C. glutamicum genomes. Despite the loss of severalpredicted open reading frames, the mutant cells exhibited normalgrowth under standard laboratory conditions. With a total of250 kb (7.5% of the genome), the 11 genomic regions were loadedwith cryptic prophages, transposons, and genes of unknown functionwhich were dispensable for cell growth, indicating recent horizontalacquisitions to the genome. This provides an interesting backgroundfor functional genomic studies and can be used in the improvementof cell traits.