Unveiling malic acid biorefinery: Comprehensive insights into feedstocks, microbial strains, and metabolic pathways

• Published in: Bioresource technology 2024-02, Vol.394, p.130265-130265, Article 130265
• Main Authors: Xu, Boyang, Zhang, Wangwei, Zhao, Eryong, Hong, Jiong, Chen, Xiangsong, Wei, Zhaojun, Li, Xingjiang
• Format: Article
• Language: English
• Subjects: Biomass; Biorefining; Consolidated bioprocessing; Fermentation; L-malic acid; Metabolic engineering
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2023.130265

[Display omitted] •Focus on key elements: feedstock, microbes and metabolic pathways.•Pivotal shift to biomass sugars from glucose for malic acid refinement.•Overview of strains for malic acid fermentation; focus on tolerance.•Strategies for redox and energy balance to boost malate production. The over-reliance on fossil fuels and resultant environmental issues necessitate sustainable alternatives. Microbial fermentation of biomass for malic acid production offers a viable, eco-friendly solution, enhancing resource efficiency and minimizing ecological damage. This review covers three core aspects of malic acid biorefining: feedstocks, microbial strains, and metabolic pathways. It emphasizes the significance of utilizing biomass sugars, including the co-fermentation of different sugar types to improve feedstock efficiency. The review discusses microbial strains for malic acid fermentation, addressing challenges related to by-products from biomass breakdown and strategies for overcoming them. It delves into the crucial pathways and enzymes for malic acid production, outlining methods to optimize its metabolism, focusing on enzyme regulation, energy balance, and yield enhancement. These insights contribute to advancing the field of consolidated bioprocessing in malic acid biorefining.