Unlocking the potential of agro-industrial wastes as valorizable substrates for bacterial carotenoid production – A comprehensive review

Abstract

The sustainable production of valorizable bacterial metabolites, such as carotenoids, using inexpensive substrates or waste materials, including agrowaste, faces several challenges. Research in this area needs to gain momentum to achieve green goals for a better tomorrow. Efficient bacterial strains from diverse natural sources must be identified to contribute to the green and economically suitable production of carotenoids using waste agrobiomass. The current investigation focuses on the current state of research, highlighting key findings and exploring the gaps in research that hinder the commercialization of these bioprocesses. The global carotenoid market is in rapid expansion due to its extensive use across diverse sectors, including the food, pharmaceutical, and cosmetic industries. Yet synthesis of carotenoids remains largely dependent on chemical methods that are expensive and lack sustainability. A detailed bibliometric analysis of reports from 2000 to 2026 (March) reveals the current status of reports and identifies relevant areas that require attention. The significance of lignocellulose-based agrowaste materials as a storehouse of nutrients for generating value-added products has been discussed, and the involvement of advanced fermentation technology in process optimization has been elaborated in this compilation. In silico analysis revealed predictive pathways leading to successful carotenoid synthesis and identified possible genes involved in these metabolic pathways. A comparative approach to different downstream processing techniques has been proposed, clearly distinguishing the steps and tools required for final product recovery, followed by physicochemical analysis to ensure product quality and purity. This study elucidates the economic relevance and practical implications of these processes in the present global scenario. Numerous reports have demonstrated that individual agro-industrial wastes can serve as substrates for carotenoid production using various microorganisms. But a holistic representation of these reports, along with bibliometric trend analysis, metabolic pathway prediction, advanced fermentation strategies, and techno-economic feasibility, makes this work a one-of-a-kind. This review report can serve as a valuable source of insights and as guidance for future researchers interested in exploring the potential of various agro-wastes as substrates for the sustainable production of bioactive carotenoids.