Astaxanthin from bacteria as a feed supplement for animals

Abstract Currently regarded as the second most important carotenoid in terms of global market value, the red-orange liposoluble diketocarotenoid—astaxanthin—is a valuable pigment renowned for its outstanding antioxidant activity and with its numerous biological activities. It is widely used in various industries including feed, food, pharmaceutical, nutraceutical, and cosmetic. For many years, it has been used as a feed additive in aquaculture and poultry farming to enhance coloration of the flesh of farm-raised aquatic animals and eggs of birds. With significant influence on animal health and nutrition, the use of astaxanthin as a supplement in animal feed has been extended to livestock as well. Synthetic astaxanthin has been the major form of astaxanthin used in animal feeds till date. However, in the wake of the recent interest in natural astaxanthin, exploration and exploitation of microbial sources of astaxanthin has received massive attention. Among the exploited microbial source is bacterial astaxanthin (the least developed and less used). This review therefore deliberates on astaxanthin from bacteria and its use of as a supplement in animal feed.