A review: Carbon-based materials as effective additives in anaerobic fermentation, focusing on microbial chain elongation and medium chain fatty acids production

Microbial chain elongation (CE), utilizing anaerobic fermentation for the synthesis of high-value medium chain fatty acids (MCFAs), merges as a promising strategy in resource sustainability. Recently, it has pivoted that the use of different types of additives or accelerantstowards enhancing the products yield and fermentation quality has got much attention, with carbon-based materials emerging as vital facilitators. Based on bibliometrics insights, this paper firstly commences with a comprehensive review of the past two decades' progress in applying carbon-based materials within anaerobic fermentation contexts. Subsequently, the recent advancements made by different research groups in order to enhance the performance of CE systemperformance are reviewed, with particular focus on the application, impact, and underlying mechanisms of carbon-based materials in expediting MCFAs biosynthesis via CE. Finally, the future research direction is prospected, aiming to inform innovative material design and sophisticated technological applications, as well as provide a reference for improving the efficiency of anaerobic fermentation of MCFAs using carbon-based material, thereby contributing to the broader discourse on enhancing sustainability and efficiency in bio-based processes. This review summarizes the current applications of carbon-based materials in anaerobic fermentation and microbial chain elongation (CE), elucidates the mechanisms of CE, and focuses on the potential mechanisms by which different carbon-based materials promote medium chain fatty acids (MCFAs) biosynthesis, aiming to provide insights for improving the efficiency and sustainability of MCFAs fermentation using carbon-based materials.