Engineered Soil Fungi Put Forward as Carbon Capture and Bioremediation Platform

A peer-reviewed review published in Communications Earth and Environment argues that genetically engineered soil fungi could mitigate carbon dioxide emissions and enhance environmental resilience, positioning a largely ignored microbial kingdom as a candidate platform for carbon management. The paper, by Davis and Tannous (2026, volume 7, article 846, DOI 10.1038/s43247-026-04088-5), arrives two decades into a period in which anthropogenic carbon dioxide emissions have risen substantially while reduction efforts have failed to deliver real progress.

The authors frame the gap precisely: plants and marine prokaryotes absorb carbon dioxide and store it as biomass, and plant carbon-fixation pathways have been engineered repeatedly. Fungi, by contrast, have received few studies. The review sets out four engineering fronts where that could change.

What does this change for carbon storage?

Two fungal compounds anchor long-term carbon retention in soil: melanin and glomalin-related soil proteins (GRSP). Fungi synthesize melanin through two mapped routes. The L-DOPA pathway starts from L-dopamine or tyrosine and proceeds to dihydroxyindole polymerization, producing DOPA melanin. The DHN pathway begins with malonyl-CoA and ends in 1,8-dihydroxynaphthalene polymerization, creating DHN melanin.

GRSP is the obstacle. The genes and pathways behind its production remain unidentified, which blocks any attempt to transfer them into new host organisms or improve biosynthetic routes for carbon dioxide sequestration. Until that gap closes, half of the soil-carbon chemistry the review describes stays outside engineering reach.

On the fixation side, the authors point to precedent. Laboratory evolution and genetic engineering have already produced an autotrophic strain of Escherichia coli that uses carbon dioxide as its only carbon source. Applying the same logic to fungi would require rewiring endogenous metabolic networks and introducing specific Calvin cycle enzymes. Yeasts such as Saccharomyces cerevisiae, already used for biofuels, could be engineered to reduce waste and redirect carbon flux toward desired products, and fatty acid production in yeasts has been exploited to capture carbon dioxide. Soil yeasts, the review notes, tolerate conditions poorly suited to standard laboratory strains, which makes them candidate engineering platforms.

Which waste streams can fungi actually degrade?

The review catalogs fungal isolates with documented activity against pollutants and polymers:

• Pestalotiopsis microspora isolates degrade polyester polyurethane and use it as a carbon source.
• Engyodontium album and Aspergillus terreus isolates break down polypropylene after ultraviolet or heat pretreatment.
• Phanerochaete chrysosporium and Aspergillus niger remove petroleum hydrocarbons from diesel- and petrol-contaminated soil.
• Fusarium solani solubilizes and degrades methane at a biodegradation rate comparable to a consortium of methanotrophic bacteria catalyzed by a cytochrome P450.

Each degradation pathway mitigates greenhouse gas release while detoxifying contaminated ground. There is a catch worth tracking: most of these activities have been reported in fungal pathogens that threaten plants and humans. The review proposes engineering the metabolic capabilities into beneficial species rather than deploying the pathogens themselves.

Can engineered symbiosis scale up carbon sequestration?

Fungi already trade with plants, exchanging improved water and nutrient uptake for carbohydrates. Greater nutrient acquisition promotes root biomass and photosynthetic capacity, which increases atmospheric carbon dioxide stored in soils and fixed into plant tissue. Engineering that mutualism is the proposed application.

The molecular levers are specific. Orchid (OrM) and ericoid (ErM) mycorrhizal fungi carry carbohydrate-active enzymes (CAZymes) that degrade plant cell walls and enable root symbiosis; characterizing the genes behind them opens the way to engineering non-symbiotic fungi for plant association. Fungi also produce signaling molecules such as lipo-oligosaccharides (LCOs), or nodulation factors, and modifying LCO biosynthetic pathways could strengthen those interactions. Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) fungi could serve as platforms for engineered nitrogen fixation, though the authors flag unresolved problems in expressing multiple genes and targeting their products to mitochondria for anaerobic reactions.

What decides what happens next?

The review closes with its own milestone list: genetic engineering hurdles, ecological safety, and the long-term stability of stored carbon must be addressed before any of these approaches can run at scale. Further research into fungal metabolic pathways and their interactions with surrounding ecosystems, the authors write, is essential to translating these developments into practical, sustainable climate solutions. For now the GRSP pathway identification stands as the first measurable gate on the carbon-storage track.