Why fungi usually need food made by something else
Autotrophy means an organism builds its own food from simple inorganic ingredients, typically using energy from sunlight or chemical reactions. Heterotrophy means it must consume organic carbon that something else produced. Fungi are conventionally heterotrophs: they secrete enzymes and absorb nutrients from decaying matter or living hosts. The supplied evidence treats fungi as organisms that combine nutritional modes rather than as independent carbon-fixers [2].
The 1991 discussion of fungi and the origin of land plants notes that some fungi are described as effectively photosynthetic, but that phrasing refers to integrated nutritional strategies, not to a fungus running photosynthesis on its own [2]. That distinction matters: a fungus can live in a way that looks plant-like without possessing the machinery to fix carbon itself.
Can yeast be made to live on CO2 and light?
Yeast is a fungus, and it is widely used as a cell factory that converts sugar into fuels, chemicals, and pharmaceuticals. A 2024 paper proposes establishing yeast as autotrophic so it could grow solely on CO2 and light, which would make it a broader platform for a sustainable society [1]. This is a research goal and engineering direction, not a report that ordinary yeast already lives that way. The abstract frames autotrophy as something to be enabled, so the claim should be read as a possibility being pursued rather than a natural fungal lifestyle [1].
When a fungus gets help from a photosynthetic partner
A different route to fungus-associated autotrophy is partnership. In a 2026 study, researchers screened filamentous fungi and paired them with diazotrophic cyanobacteria, which are photosynthetic microbes that can also fix nitrogen. They identified mutually supportive consortia capable of sustained growth and biomineral formation from granular feedstocks [3]. Here the autotrophic partner is the cyanobacterium, not the fungus. The system as a whole is autotrophic-heterotrophic: the cyanobacterium supplies fixed carbon, and the fungus contributes to the consortium.
This is a synthetic, human-assembled system rather than a naturally autotrophic fungus. It shows that fungi can be part of a self-sustaining autotrophic community, which is a narrower and more carefully bounded claim than saying a fungus itself is autotrophic [3].
So is the answer yes, no, or not yet?
For naturally occurring fungi, the evidence points to no: they are heterotrophs, and descriptions of them as photosynthetic reflect integrated nutritional modes rather than independent carbon fixation [2]. For engineered or assembled systems, the answer is more open. Yeast has been proposed as a candidate for autotrophic growth on CO2 and light [1], and filamentous fungi have been experimentally paired with cyanobacteria in consortia that grow and biomineralize [3]. Neither result establishes a free-living autotrophic fungus in nature. The practical answer is that autotrophy in fungi is currently a frontier of engineering and synthetic biology, not a standard fungal mode of life.
Sources used in this answer
Autotrophic yeast
The paper explores establishing yeast, a fungus, as autotrophic so it could grow solely on CO2 and light as a sustainable cell factory.
21 Fungi and the Origin of
The paper discusses fungi in relation to combined nutritional modes and notes that some are described as effectively photosynthetic.
Weaving Life Into Regolith: Synthetic Autotrophic–Heterotrophic Consortia for Autonomous Biofabrication From Granular Feedstocks
The paper experimentally paired filamentous fungi with diazotrophic cyanobacteria to form mutually supportive consortia capable of sustained growth and biomineral formation.