A review of the research progress on co-cultivation of symbiotic methanotroph bacteria with algae

Abstract This review provides an in-depth analysis of recent advancements in co-cultivation strategies involving methanotroph and algal symbiotic bacteria, while exploring their biotechnological applications. The study specifically highlights the consortium's potential for simultaneous methane and carbon dioxide utilisation in producing value-added bioproducts, including biofuels, single-cell proteins, single-cell oils, and biodegradable plastics. A comprehensive examination is presented regarding the underlying mechanisms of microbial cross-feeding, critical influencing factors (e.g., nutrient exchange dynamics, redox balance maintenance, and quorum sensing regulation), and system optimisation approaches for enhanced symbiotic efficiency. Current technical bottlenecks in industrial scalability are critically addressed, particularly focusing on reactor type, metabolic flux imbalances, and ecological stability maintenance in open systems. Future research directions are proposed to emphasise multi-omics-guided consortia design, synthetic biology-enabled metabolic pathway engineering, and AI-driven cultivation parameter optimisation. By synthesising cutting-edge findings from recent studies, this review establishes a systematic framework for understanding and engineering symbiotic microbial systems, ultimately contributing to the development of carbon-negative biomanufacturing platforms that align with circular economy principles.