Sustainable carotenoid production using amylaceous agro-industrial byproducts: process efficiency and environmental assessment

Abstract The transition to production systems with sustainable design requires innovative biotechnological approaches to obtain high-value-added compounds from renewable resources. Microbial carotenoids, known for their antioxidants and antimicrobial properties, have promising applications in the food, pharmaceutical, and cosmetic industries. However, their large-scale production is constrained by high costs, limiting commercial viability. In this study, grain by-products were explored as sustainable low-cost feedstocks for microbial carotenoid production, enhancing both economic and environmental feasibility. Corn, soybean, rice, and wheat bran hydrolysates were evaluated as carbon and nutrient sources, supporting microbial growth and carotenoid synthesis without additional supplementation or detoxification. Despite variations in hydrolysate composition, carotenoid production was achieved across all substrates, with rice and soybean bran yielding 24.55 and 28.41 mg carotenoids /L growth medium , respectively. Life cycle assessment (LCA) identified rice bran as the most environmentally favorable option, reinforcing its potential as a sustainable bioprocess feedstock. This study highlights the valorization of agro-industrial residues as an efficient strategy to reduce production costs and environmental impact, contributing to the development of more sustainable biotechnologies for carotenoid synthesis and beyond.