A two-member synthetic fungal-algal community pairing Saccharomyces cerevisiae with Chlamydomonas reinhardtii under engineered laboratory conditions that force reciprocal carbon and nitrogen exchange. Yeast metabolizes glucose and supplies carbon dioxide to the alga, while the alga photosynthetically releases oxygen and converts nitrite into reduced nitrogen that supports yeast growth.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Saccharomyces cerevisiae | NCBITaxon:4932 · TaxonMech · TraitMech |
CROSS_FEEDER
SECONDARY_FERMENTER
|
N/A |
| Chlamydomonas reinhardtii | NCBITaxon:3055 · TaxonMech · TraitMech |
PRIMARY_PRODUCER
CROSS_FEEDER
|
N/A |
Ecological Interactions
The graph shows only explicitly linked interaction participants. Community members without an asserted participant link are omitted; membership alone does not imply an interaction.
Yeast Carbon Dioxide Provisioning
CROSS_FEEDINGIn the sealed illuminated coculture, yeast glucose metabolism supplies carbon dioxide assimilated by the algal partner. This is the carbon arm of the authors' experimentally supported reciprocal carbon/nitrogen mutualism. The source does not isolate fermentation as the only route of yeast carbon dioxide production.
Source Taxon: Saccharomyces cerevisiae
Target Taxon: Chlamydomonas reinhardtii
Metabolites: glucose (CHEBI:17234 · MediaIngredientMech · CMMMech), carbon dioxide (CHEBI:16526 · MediaIngredientMech · CMMMech)
Biological Processes:
- photosynthesis (GO:0015979 · PathwayMech)
PARTIAL: yeast-derived carbon dioxide sustains the alga that supplies reduced nitrogen to yeast, closing the resource-dependence loop. Coculture and resource-availability comparisons support this reciprocal mechanism, but do not separately quantify how a change in carbon transfer changes ammonia release.
Evidence
-
PMID:24994654 - SUPPORT (IN_VITRO)"S. cerevisiae metabolizes glucose to carbon dioxide (CO2), a carbon source that C. reinhardtii fixes via photosynthesis"
Algal Reduced Nitrogen Provisioning
CROSS_FEEDINGAlgal nitrite metabolism supplies ammonia usable by yeast in the carbon/nitrogen mutualism. The dependence is conditional on the resource environment, not an unconditional property of these species; external reduced nitrogen can remove yeast dependence on the alga.
Source Taxon: Chlamydomonas reinhardtii
Target Taxon: Saccharomyces cerevisiae
Metabolites: nitrite (CHEBI:16301 · MediaIngredientMech · CMMMech), ammonia (CHEBI:16134 · MediaIngredientMech · CMMMech)
Biological Processes:
- interspecies interaction between organisms (GO:0044419 · PathwayMech)
PARTIAL: algal reduced nitrogen sustains yeast growth and therefore the yeast partner supplying carbon dioxide. This reciprocal support is consistent with the reported dependence, not a measured feedback gain or a separate temporal causal experiment.
Evidence
-
PMID:24994654 - SUPPORT (IN_VITRO)"C. reinhardtii reduces nitrite (NO2−) into ammonia (NH3) (14), which yeast can use as a nitrogen source"
Associated Datasets
| Dataset | Type | Repository | Accession |
|---|---|---|---|
|
Yeast-alga early adaptation sequencing data
Raw sequencing data for the later exact-composition S. cerevisiae-C. reinhardtii experimental-evolution study. |
GENOMICS | NCBI_BIOPROJECT | PRJNA735257 |
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN Is algal oxygen release a demonstrated additional benefit to yeast in this exact coculture?
The primary manuscript depicts oxygen release, but the reviewed main text establishes reciprocal carbon/nitrogen dependence rather than an isolated oxygen-mediated yeast benefit. The two-node resource loop is retained with PARTIAL mediation limits. The oxygen-benefit assertion is removed pending exact-system evidence. This does not assert that yeast cannot use oxygen. Broader re-evidencing remains in issue765, and cache-version/license provenance is tracked separately.
Attaches to: ecological_interactions#Yeast Carbon Dioxide Provisioning, ecological_interactions#Algal Reduced Nitrogen Provisioning
1 evidence item(s)
an environment requiring reciprocal carbon and nitrogen exchange
The abstract supports the established reciprocal resource basis, not an oxygen-specific benefit.
External Resources
| Name | Repository | Resource ID |
|---|---|---|
|
Exact-composition publication - fungal-algal obligate mutualism
Primary paper establishing the engineered S. cerevisiae-C. reinhardtii obligate mutualism. |
OTHER | PMID:24994654 |
|
||
|
Exact-composition publication - yeast-alga early adaptation
Later experimental-evolution study using the same two-species S. cerevisiae-C. reinhardtii composition. |
OTHER | doi:10.1038/s41559-022-01923-8 |
Environmental Factors
| Factor | Value | Unit |
|---|---|---|
| atmospheric carbon dioxide exclusion | N/A | |
| glucose and nitrite availability | N/A |
Growth Media
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