Detailed biosynthetic pathway to decaprenoxanthin diglucoside in Corynebacterium glutamicum and identification of novel intermediates

Carotenogenic mutants of Corynebacterium glutamicum were analyzed for their carotenoid content. Mutant MV10 accumulated the same carotenoids as the wi ld-type, decaprenoxanthin, decaprenoxanthin monoglucoside, and (2R,6R,2 'R, 6 'R)-decaprenoxanthin di-(beta -D)-glucoside, but in three-fold higher amo unts. In addition, decaprenoxanthin diglucoside fatty acid esters and the i ntermediates nonaprene, 2-(3-methyl-2-butenyl)-epsilon,psi -carotene, and s arcinene, 2,2 ' -bis(3-methyl-2-butenyl)-epsilon,epsilon -carotene were ide ntified as minor carotenoids. The pink mutants MV40 and MV60 synthesized on ly lycopene. From another pink mutant, MV70, novel C-50-carotenoids were is olated. By NMR and mass spectroscopy, nonaflavuxanthin, 2-(4-hydroxy-3-meth yl-2-butenyl)-1,16-didehydro-1,2-dihydro-psi,psi -carotene, and flavuxanthi n, 2,2 ' -bis(4-hydroxy-3-methyl-2-butenyl)-1,16,1 ' ,16 ' -tetradehydro-1, 2,1 ' ,2 ' -tetrahydro-psi,psi -carotene, were identified. The identificati on of these intermediates revealed the detailed pathway for the formation o f decaprenoxanthin derivatives in Corynebacterium glutamicum.