FIG 4.

Zeaxanthin production by GF1. (a) Zeaxanthin biosynthesis pathway and corresponding genes of GF1. GGPP, geranylgeranyl diphosphate. (b) Zeaxanthin biosynthesis gene cluster. The annotation of each gene, which starts with “peg,” is listed in Table S4 in the supplemental material. (c) LC-MS/MS chromatograms of zeaxanthin in the methanol extract of GF1. Zeaxanthin was detected in positive ion mode by MRM from m/z 568.30 to 476.35, 119.15, and 145.15. A 1-μg/ml zeaxanthin standard is shown for retention time comparison. Zeaxanthin was not detected from the methanol used for extraction.