Carotenoids are a class of pigments distributed ubiquitously in nature. These pigments have received considerable attention because of their biotechnological applications and due to their benefits in the fields of human healthcare.

Carotenoids have received much attention because of the variety of important biological roles they perform in all living systems. In the majority of organisms, the most relevant biological functions performed by the carotenoids are associated with their antioxidant properties, which are a direct outcome of their molecular structure.

Xanthophylls, for instance, perform the role of free-radical scavengers, potent quenchers of ROS (reactive oxygen species) and RNS (reactive nitrogen species) and chain-breaking antioxidants. 

Therefore, astaxanthin and canthaxanthin (which are xanthophylls) are better antioxidants and scavengers of free radicals compared to β-carotene. In the last few decades, the research on carotenoids, and their implementation in markets have advanced considerably.

However, further advancement of this development is required, especially in the processes used to obtain carotenoids; for example, chemical synthesis must be replaced by biological production

In this way, the reduction in the costs of the production of carotenoids and the generation of non-active waste would be achieved. Marine microorganisms offer numerous advantages as natural sources of carotenoids: 

1. They usually have low nutritional requirements during their growth and cultivation, which reduces the production costs

2. The culture medium in which they grow contains moderate or high salt concentrations, which prevents contamination with other microorganisms, reducing the costs and facilitating the downstream processes; 

3. These microorganisms are also a source of rare carotenoids, the properties of which are yet to be explored, for example, bacterioruberin from Haloarchaea.

In a more applied sense, it should be noted that an extensive bibliography is available on the biochemical characteristics of carotenoids and their potential beneficial effects on human health. 

However, further studies on the direct and real-time effects of carotenoids on human populations are required, to corroborate their antioxidant, antitumor, anti-aging and various other roles. 

On the nutritional level, the use of the carotenoids obtained from marine biomass is well studied; also, their use is common in the diets of people in several countries, especially in Asia.

The industry must continue to take steps in the direction of improving the organoleptic properties, which are altered by the addition of marine biomass to the conventional foods; especially in Europe, where such functional foods are relatively recent and not yet completely accepted.