Co-culture engineering for sustainable bacterial cellulose manufacturing: Process intensification, functional materials and industrial translation

Bacterial cellulose (BC) has emerged as a promising bio-based material owing to its unique nanofibrillar architecture, high purity, excellent mechanical properties, and broad application potential in biomedical, environmental, and advanced material fields. However, conventional monoculture-based production systems remain constrained by low productivity, inefficient substrate utilization, oxygen-transfer limitations, and poor scalability, which hinder the industrial deployment of BC. In recent years, microbial co-culture engineering has emerged as a promising process-intensification strategy to address these challenges through metabolic specialization, cooperative resource utilization, and dynamic microenvironment regulation. This review provides a comprehensive engineering-oriented analysis of microbial co-culture systems for BC biomanufacturing. Emphasis is placed on the engineering principles underlying co-culture design, including metabolic division of labor, cross-feeding interactions, population regulation, and cooperative carbon conversion. We further discuss how these mechanisms translate into practical process advantages, such as enhanced BC productivity, improved mass transfer, increased process robustness, and reduced production costs. Repressentative bacteria-bacteria and bacteria-microalgae co-culture platforms are critically evaluated from the perspectives of fermentation performance, reactor operation, scalability, and sustainability. Beyond productivity enhancement, the review highlights emerging opportunities for co-culture-enabled in situ functionalization and the fabrication of advanced BC-based composite materials, thereby establishing direct links between microbial community engineering, material structure, and functional performance. Finally, current bottlenecks and future directions are discussed, including community stability, scale-up challenges, reactor engineering, process monitoring, and intelligent biomanufacturing strategies. This review aims to provide a technology-focused framework for translating microbial co-culture systems from laboratory studies to scalable and application-oriented BC manufacturing.