MycUpscaling · Upscaling in vitro arbuscular mycorrhizal fungi inoculum production via combinatorial lipid metabolic engineering of host plants

Upscaling in vitro arbuscular mycorrhizal fungi inoculum production via combinatorial lipid metabolic engineering of host plants

The MycUpscaling project addresses the major limitation in the large-scale, clean, and cost-efficient production of arbuscular mycorrhizal fungi (AMF) inoculum. Although AMF are critical symbiotic organisms supporting nutrient uptake in over 70% of land plants—particularly phosphorus—their industrial production remains constrained. Current large-scale methods mostly rely on in vivo soil-based systems, which are space-demanding and prone to microbial contamination. In contrast, in vitro systems, while cleaner, are technologically demanding and yield lower spore outputs, limiting their commercial application. This bottleneck is compounded by the fungi’s dependency on plant-derived lipids (especially TAGs) for spore formation and propagation, and the limited understanding of lipid transfer mechanisms at the plant–AMF interface. The project’s outcomes are crucial for sustainable agriculture, aligning with the EU’s Green Deal and Farm-to-Fork strategies. By improving the mass production of biofortified AMF inoculum—rich in triacylglycerol and produced under sterile, controlled conditions—MycUpscaling offers a biotechnological alternative to synthetic fertilizers, reduces environmental impact, and improves crop resilience. This supports ecological intensification of farming practices, restores soil biodiversity, and enhances food security, particularly under the pressures of climate change and land degradation. The overarching objective is to develop a novel platform for high-quality, high-yield in vitro AMF inoculum production by engineering host plant lipid metabolism. This goal is broken down into three specific and interlinked objectives: Engineering plant lipid metabolism – To identify optimal gene combinations that enhance TAG biosynthesis and transfer to AMF in Medicago truncatula roots, using a combinatorial “Push, Pull, Package” (PPP) metabolic engineering strategy. Deciphering metabolic flux responses – To trace how the plant’s lipid metabolic network is rewired in response to genetic modifications, by using isotopic labeling and lipidomics to monitor fatty acid flux toward AMF-compatible lipid species. Assessing scalability and production cost – To evaluate the engineered systems’ suitability for large-scale AMF spore production in Petri plates and bioreactors, and to perform cost-efficiency analyses to ensure industrial relevance.

Data: CORDIS, © European Union