In a groundbreaking advancement that leverages the power of photosynthesis for sustainable biotechnology, researchers at the Institute of Science Tokyo have successfully engineered cyanobacteria to produce sulfated polysaccharides (SPS), a class of valuable biomolecules with extensive applications in pharmaceuticals, cosmetics, and functional materials. This feat was achieved through the transfer and integration of a complete gene cluster responsible for SPS biosynthesis from one species of cyanobacteria to another, opening new frontiers in synthetic biology and green manufacturing.
Sulfated polysaccharides are complex carbohydrates characterized by the presence of sulfate groups attached to sugar monomers. These molecules exhibit unique physical and biological properties such as antiviral, anticoagulant, and anti-inflammatory effects, which have made them indispensable in a variety of industrial sectors. Traditionally derived from animal and marine sources, SPS extraction raises ecological concerns due to overharvesting and sustainability issues. Therefore, engineering microbial factories for SPS biosynthesis offers a promising alternative that aligns with the goals of environmental preservation and resource efficiency.
The team, led by Assistant Professor Kaisei Maeda in collaboration with Tokyo University of Agriculture’s Professor Satoru Watanabe, embarked on this ambitious project by focusing on cyanobacteria, photosynthetic microorganisms capable of converting sunlight and atmospheric CO2 into valuable biochemicals. Cyanobacteria are nature’s own solar-powered bioreactors, and several species naturally produce sulfated polysaccharides. However, controlled and scalable production of SPS using these organisms has remained elusive due to the complexity of their biosynthetic pathways.
Targeting the model cyanobacterium Synechocystis sp. PCC 6803 – an established producer of an SPS known as synechan – the researchers first identified and isolated the entire gene cluster orchestrating synechan biosynthesis and regulation. This genetic ensemble encompasses multiple enzymatic and regulatory elements that coordinate the assembly, sulfation, and export of the polysaccharide. Successfully decoding this pathway presented an opportunity to transplant this metabolic machinery into a cyanobacterial chassis more amenable to laboratory manipulation.
The recipient host, Synechococcus elongatus PCC 7942, naturally lacks the ability to produce sulfated polysaccharides, making it an ideal candidate for genetic engineering experimentation. By inserting the full gene cluster from Synechocystis into Synechococcus, the team reconstructed the biosynthetic network within a non-native organism. The engineered Synechococcus strain astonishingly began synthesizing and secreting extracellular sulfated polysaccharides, confirming the functionality and interoperability of the introduced gene system across species boundaries.
This cross-species gene transfer of a complex biochemical pathway demonstrates not only the modularity of microbial metabolism but also the feasibility of reconstructing sophisticated biosynthetic routes in new cellular contexts. The researchers validated their findings using a combination of microscopy techniques and biochemical assays, which revealed extracellular accumulation of SPS structurally analogous to that produced by the original Synechocystis strain. In-depth gene expression analyses indicated coordinated activation of the inserted genes and systemic metabolic shifts in the host, reflecting cellular adaptation to polysaccharide biosynthesis.
The rise in SPS production imposed a metabolic burden on the engineered cyanobacteria, which manifested as altered growth patterns and gene expression profiles indicative of a stress response state. Despite this, the cells prioritized SPS biosynthesis, showcasing the intricate balance between cellular fitness and engineered function. Understanding these physiological trade-offs is vital for optimizing production yields and process scalability in future research endeavors.
This pioneering work introduces a sustainable and controllable biomanufacturing platform for sulfated polysaccharides, leveraging photosynthetic microorganisms as green cell factories. Unlike conventional animal- or marine-derived SPS, microbial production system bypasses environmental constraints, potentially reducing ecological footprints while offering customizable biomolecule synthesis. The implications for industry are significant, heralding new strategies for producing high-value biopolymers through eco-friendly and cost-effective methods.
Looking forward, advances in synthetic biology hold the promise of fine-tuning polysaccharide structure and functionality by manipulating biosynthetic genes and regulatory circuits. Such flexibility could enable the design of tailor-made sulfated polysaccharides with enhanced bioactivity or novel functionalities suited to specific biomedical or industrial applications. Furthermore, engineering cyanobacteria capable of producing diverse biomaterials could revolutionize the manufacturing landscape by employing sunlight-driven biochemical processes.
With the successful demonstration of complex gene cluster transfer between cyanobacterial species, Science Tokyo’s research team sets a precedent for future synthetic biology projects that exploit photosynthetic microbes as versatile production platforms. Integrating carbon fixation with engineered biosynthesis lays the foundation for a new era of sustainable biomaterial production, combining innovation with environmental stewardship. The newfound ability to program cyanobacteria with sophisticated metabolic capacities paves the way toward carbon-neutral and resource-efficient biomanufacturing ecosystems.
This study not only advances fundamental understanding of cyanobacterial metabolism and gene regulation but also moves us closer to realizing synthetic photosynthetic organisms as factories for industrially valuable compounds. By harnessing the natural power of photosynthesis alongside synthetic genetic elements, these engineered microbes exemplify the fusion of biology and engineering to address pressing global challenges related to sustainability, resource scarcity, and material innovation.
Institute of Science Tokyo, established in 2024 from the merger of Tokyo Medical and Dental University and Tokyo Institute of Technology, remains at the forefront of interdisciplinary research, fostering developments that synergize chemistry, life sciences, and engineering. This latest achievement underscores their commitment to advancing science and human well-being, contributing significantly to cleaner production technologies and bio-based economies.
The research was supported by key funding bodies including the Japan Science and Technology Agency and the NODAI Genome Research Center. Published in the April 28, 2026, edition of Scientific Reports, it exemplifies cutting-edge experimental work pushing the boundaries of microbial engineering and synthetic biology. The authors report no competing interests, ensuring the integrity and collaborative spirit of the work.
Subject of Research: Cells
Article Title: Transfer of the synechan biosynthesis and regulatory pathway enables sulfated polysaccharide production in Synechococcus elongatus PCC 7942
News Publication Date: 28-Apr-2026
Web References: https://doi.org/10.1038/s41598-026-46439-4
Image Credits: Institute of Science Tokyo (Science Tokyo)
Keywords
Sulfated polysaccharides, cyanobacteria, genetic engineering, synthetic biology, photosynthesis, synechan, biomanufacturing, green chemistry, microbial metabolism, biosynthetic pathways, metabolic engineering, biomaterials
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