Carotenoid biosynthesis in C. glutamicum ATCC 13032 and gene deletion and complementation analysis of carotenogenic genes. Cell pellets of C. glutamicum deletion mutants lacking one of the carotenogenic genes crtB, crtI, crtEb or crtY
and the wild type and the corresponding complemented strains (right, EV: empty vector). The cells were grown in 50 ml CGXII medium with 100 mM glucose, inoculated to an OD600 of 1 with a BHI overnight culture. The overexpression was induced at the beginning of the cultivation with 1 mM IPTG.