A review of the use of wheat bran waste as a sustainable nutrient source to improve growth, protein synthesis, and biopigment production in the microalgae Dunaliella salina

The increasing global demand for high-value bioactive compounds such as beta-carotene, protein, biolipids, and antioxidants has led to the attention of microalgae as rich sources for the food, pharmaceutical, and cosmetic industries. Dunaliella salina is one of the most carotenogenic microalgae that is capable of producing significant amounts of beta-carotene under stress conditions. However, commercial production of this algae is challenging due to the need for rich culture media and high nutrient costs. On the other hand, wheat bran, which is a by-product of wheat grain processing, is one of the most abundant wastes in the flour and bakery industries, with millions of tons of it produced annually. This waste is rich in fiber, protein, essential amino acids, B vitamins, minerals such as iron, magnesium, zinc, phosphorus, and antioxidant phenolic compounds. These properties have made wheat bran a cheap and sustainable nutrient source for use in microalgae cultivation. Studies show that adding hydrolyzed wheat bran extract to Dunaliella salina culture medium increases biomass by ۲۰-۴۵%, increases protein synthesis, increases absorbable nitrogen content, and improves carotenoid synthesis, especially beta-carotene. Phenolic compounds in bran reduce cellular oxidative stress and stimulate metabolic pathways related to carotenoid production. Also, the presence of free amino acids can improve photosynthesis, growth, and nitrogen metabolism. In this article, while examining the chemical composition of wheat bran and the technologies for extracting nutrients from it, the effect of this waste on growth, protein synthesis, and bio-pigment production in Dunaliella salina is reviewed. The results show that wheat bran is a valuable waste that can be used as a supplement to the culture medium and can significantly reduce the cost of producing organic products.

کلیدواژه ها:

Wheat bran ، agricultural waste ، beta-carotene ، biomass ، culture medium ، antioxidants