Microbial immobilization is a critical strategy for enhancing bioethanol production by improving process efficiency and microbial reusability. Despite the progressive research over the past two decades, a comprehensive bibliometric assessment mapping research evolution in microbial immobilization for bioethanol production has been largely lacking. This study presents a bibliometric analysis of research on microbial immobilization for bioethanol production from 2005 to 2025. Publication data were retrieved from the Web of Science database and analyzed using VOSviewer to assess publication growth, citation patterns, collaboration networks, and keyword co-occurrence. An initial search using the terms “bioethanol” and “immobilization” yielded approximately 98,000 records, which were refined to 597 relevant publications through a PRISMA-based screening process. The findings reveal that India, China, Brazil, and the United States lead research output, supported by strong institutional collaborations and targeted funding. Prominent contributors include Da Silva SS, Nikolić S, and Rakin M. Encapsulation, adsorption, and flocculation emerged as the most studied immobilization techniques, with alginate, chitosan, and silica as widely used materials, while sweet sorghum, rice straw, cheese whey, and molasses were the predominant feedstocks. Saccharomyces cerevisiae , Zymomonas mobilis , and Pichia stipitis were the most frequently investigated microorganisms. Emerging themes such as magnetic nanomaterials, smart and mesoporous supports, microfluidic systems, and integrated biorefinery concepts indicate a shift toward advanced immobilization platforms. Biocatalyst stability and mass transfer limitations are identified as key challenges to microbial immobilization. This analysis provides a strategic overview for researchers and organizations to track global competition, identify collaborators and research gaps, and highlight emerging research directions in microbial immobilization for bioethanol production. • 597 publications (2005–2025) analyzed using Web of Science and VOSviewer. • India, China, Brazil, and the USA dominate global research output. • Encapsulation, adsorption, and flocculation are the leading immobilization strategies. • Major benefits are reusability for batch processes and continuous flow for packed-bed processes. • Emerging trends include magnetic nanomaterials and biorefinery concepts.
Abdulmumin et al. (Thu,) studied this question.