Fig. 1
From: Advances and trends for astaxanthin synthesis in Phaffia rhodozyma
Astaxanthin biosynthetic pathways in P. rhodozyma. Enzymes are as follows: (1) Mevalonate pathway: AACT, acetyl-CoA acetyltransferase; HMGS, hydroxymethylglutaryl-CoA synthase; HMGR, 3-hydroxy-3-methylglutaryl-CoA reductase; MK, mevalonate kinase; PMK, phosphomevalonate kinase; MVD, mevalonate diphosphodecarboxylase. (2) Isoprenoids pathway: idi, isopentenyl pyrophosphate isomerase; ERG20, geranyl pyrophosphate synthase; CrtE, geranylgeranyl pyrophosphate synthase; CrtYB, phytoene-β-carotene synthase. (3) Carotenoids pathway: CrtI, phytoene desaturase; CrtYB, lycopene cyclase; CrtS, astaxanthin synthetase; CrtR, cytochrome P450 reductase. The Solid arrows indicate a single step reaction. The dashed arrows indicate multistep reactions