Phytoene desaturase (lycopene-forming) Phytoene desaturase (lycopene-forming) Phytoene desaturase (lycopene-forming) (CrtI, "four-step phytoene desaturase") (, "15-cis-phytoene:acceptor oxidoreductase (lycopene-forming)") are enzymes found in archaea, bacteria and fungi that are involved in carotenoid biosynthesis. They catalyze the conversion of colorless 15-"cis"-phytoene into a bright red lycopene in a biochemical pathway called the poly-trans pathway. The same process in plants and cyanobacteria utilizes four separate enzymes in a poly-cis pathway. Bacterial phytoene desaturases were shown to require FAD as a cofactor for their function. During the chemical reaction in total four additional double bonds are introduced into phytoene: In 2000 it was discovered that the gene insertion
Lycopene food, or as a dietary supplement, and any of these cancers." A 2017 review concluded that tomato products and lycopene supplementation had small positive effects on cardiovascular risk factors, such as elevated blood lipids and blood pressure. A 2010 review concluded that research has been insufficient to establish whether lycopene consumption affects human health. Lycopene has been studied in basic and clinical research for its potential effects on cardiovascular diseases and prostate cancer, although results through 2017 have not changed the prevailing FDA view that evidence of benefit remains inconclusive. Lycopene Lycopene (from the neo-Latin "Lycopersicum", the tomato species) is