Screening, Isolation, and Identification of Zeaxanthin-Producing Bacteria.

Zeaxanthin is a yellow xanthophyll, dihydroxy-carotenoid, that is naturally found in some of the green, orange, and yellow vegetables and fruits and has a powerful antioxidant activity. Epidemiological evidences suggest that increasing the consumption of zeaxanthin in the diet is associated with a lower risk of age-related macular degeneration (ARMD) and cataracts, two of the leading causes of blindness in the world. Zeaxanthin is a promising nutraceutical/colorant with many applications in feed, food, and pharmaceutical industries. Currently, the commercial production of zeaxanthin is dependent on synthetic routes with limitation in production from biological sources. However, the biotechnological production of natural zeaxanthin is favored due to its safety, potential large-scale production and consumers' preference for natural additives. In this chapter, we describe a rapid screening method based on 16S rRNA gene sequencing and effective HPLC with diode array detector/MS methods for the isolation and identification of zeaxanthin-producing bacteria and their carotenoid analysis.