Figure 1.

Diagram of the astaxanthin biosynthetic pathway in X. dendrorhous. The astaxanthin biosynthesis pathway in X. dendrorhous proposed by [21] and [22]. Metabolite abbreviations: IPP (isopentenyl pyrophosphate), DMAPP (dimethylallyl pyrophosphate), GPP (geranyl pyrophosphate), FPP (farnesyl pyrophosphate), GGPP (geranylgeranyl pyrophosphate) and HDCO (3-hydroxy-3′,4′-didehydro-β,ψ-carotene-4-one). The names of the genes controlling each step are written in red: idi (IPP-isomerase), crtE (geranylgeranyl pyrophosphate synthase), crtYB (PBS, phytoene-β-carotene synthase), crtI (PDS, phytoene desaturase), crtS (astaxanthin synthase) and crtR (cytochrome P450 reductase).