*Review* **Marine Microalgae for Potential Lutein Production**

## **Sushanta Kumar Saha \* , Hande Ermis and Patrick Murray**

Shannon Applied Biotechnology Centre, Limerick Institute of Technology, Moylish Park, V94 E8YF Limerick, Ireland; Hande.Ermis@lit.ie (H.E.); Patrick.Murray@lit.ie (P.M.)

**\*** Correspondence: Sushanta.Saha@lit.ie; Tel.: +353-61-293-536

Received: 8 September 2020; Accepted: 13 September 2020; Published: 16 September 2020

**Abstract:** Lutein is particularly known to help maintain normal visual function by absorbing and attenuating the blue light that strikes the retina in our eyes. The effect of overexposure to blue light on our eyes due to the excessive use of electronic devices is becoming an issue of modern society due to insufficient dietary lutein consumption through our normal diet. There has, therefore, been an increasing demand for lutein-containing dietary supplements and also in the food industry for lutein supplementation in bakery products, infant formulas, dairy products, carbonated drinks, energy drinks, and juice concentrates. Although synthetic carotenoid dominates the market, there is a need for environmentally sustainable carotenoids including lutein production pathways to match increasing consumer demand for natural alternatives. Currently, marigold flowers are the predominant natural source of lutein. Microalgae can be a competitive sustainable alternative, which have higher growth rates and do not require arable land and/or a growth season. Currently, there is no commercial production of lutein from microalgae, even though astaxanthin and β-carotene are commercially produced from specific microalgal strains. This review discusses the potential microalgae strains for commercial lutein production, appropriate cultivation strategies, and the challenges associated with realising a commercial market share.

**Keywords:** commercial microalgae cultivation; dietary supplements; lutein production; marine microalgae
