Saccharomyces cerevisiae
Enable an agent to identify Saccharomyces cerevisiae, assess a particular strain or culture, and decide whether it is suitable for a specified research or fermentation use.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to identify Saccharomyces cerevisiae, assess a particular strain or culture, and decide whether it is suitable for a specified research or fermentation use.
Saccharomyces cerevisiae is a species of unicellular ascomycete fungus that commonly reproduces by budding, ferments sugars to ethanol and carbon dioxide, and is widely used in food production, biotechnology and research.
It can be Resolve a culture's species and strain identity against reference material and identification evidence.; Compare strains for a specified fermentation or experimental objective using measurements made under comparable conditions.; Determine whether documented nutrient dependencies and carbon-use phenotypes match a proposed cultivation environment.; Assess whether mating, sporulation or genetic manipulation is compatible with the recorded strain state.; Accept, quarantine, re-identify or replace a culture based on identity, purity, viability and stability evidence.; Select a preservation and recovery approach supported for the strain and verify its condition after recovery..
Distinguishing features
Require a documented species-identification method that distinguishes S. cerevisiae from close relatives; budding morphology alone does not establish species identity.
Check whether identification evidence supports S. cerevisiae or a hybrid involving it, particularly when the material is described only as brewing yeast.
Treat baker's yeast, brewer's yeast and similar use labels as insufficient identifiers without a strain or species record.
Distinguish a viable S. cerevisiae culture from inactivated biomass or yeast extract before assigning growth or fermentation capabilities.
Separate species membership from strain performance: a laboratory strain and a production strain need independent evidence of suitability.
Scope
+ Species identification and differentiation from related Saccharomyces species and hybrids
+ Strain identity, provenance, genotype and modification history
+ Ploidy, mating type, reproduction and population heterogeneity
+ Fermentation, respiration, nutrient requirements and stress responses
+ Culture viability, purity, stability and suitability for an intended use
- Yeasts or fungi as broader biological groups
- Other Saccharomyces species and interspecies hybrids as independent organisms
- Bread, beer, wine, yeast extracts and other products containing or derived from the organism
- Fermenters, cultivation equipment and complete manufacturing processes
- Host diseases, clinical diagnosis and treatment
- Purified metabolites and their chemical specifications
Characteristics
- Species assignment
- Supported S. cerevisiae assignment | unresolved Saccharomyces | suspected hybrid | conflicting identification Determines whether this model applies and whether further identification is necessary.
- Strain and lineage
- Culture-collection accession, supplier identifier, isolate identifier and parent-strain links Connects observations to the correct biological material rather than to the species in general.
- Ploidy and chromosome state
- Haploid | diploid | polyploid | aneuploid | mixed | unknown, with supporting assay Affects genetic interpretation, reproductive options and strain stability.
- Mating-type configuration
- MAT locus configuration, switching capability and assay evidence, or unknown Supports decisions about mating, crossing and maintenance of a defined lineage.
- Genetic dependencies and modifications
- Documented alleles, auxotrophies, constructs, selectable markers and mitochondrial alterations Determines medium requirements and limits which phenotypes can be attributed to the unmodified organism.
- Viability
- Percent viable cells or CFU/mL, with method, sampling time and culture conditions Distinguishes measured living material from total biomass and supports inoculum assessment.
- Carbon-use phenotype
- Growth, substrate consumption and product formation for each tested carbon source under stated oxygen conditions Prevents assumptions that all strains use the same substrates or produce equivalent fermentation outcomes.
- Growth and fermentation performance
- Specific growth rate in h^-1, substrate consumption in g/L/h and ethanol yield in g/g, with assay conditions Makes strain suitability testable without treating context-dependent performance as a species constant.
- Culture purity
- No contaminants detected by stated tests | mixed culture | contamination detected | untested Determines whether observed behavior can be assigned to the intended strain.
- Stress-response profile
- Growth or survival across tested temperature, pH, ethanol concentration and osmotic conditions Defines an evidence-based operating range for the particular strain and application.
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Species and strain identity Establish what biological material is present and which lineage-specific records apply.
Common yeast names and intended uses do not reliably establish S. cerevisiae identity or strain equivalence.
Species boundary
Separate S. cerevisiae from related species, ambiguous isolates and hybrids.
Evidence for species assignment
Record the identification method, reference comparison and its ability to resolve close relatives or mixed ancestry.
- Which identification results support assigning this isolate to S. cerevisiae? provenance
- Can the method distinguish close Saccharomyces relatives and detect hybrid ancestry, or does that remain unresolved? boundary
Strain provenance
Connect the working culture to a traceable isolate, accession or parent lineage.
Lineage and aliases
Record strain identifiers, aliases, source material and derivation history without equating similar commercial names.
- Which accession or isolate identifier anchors this strain, and where did the current culture originate? provenance
- Which names denote the same documented lineage, and which merely describe a baking, brewing or other use? boundary
Genome and reproductive state Represent the genetic configuration and reproductive capabilities of the particular strain.
Ploidy, mating configuration and engineered dependencies materially change what an agent can infer or do.
Genetic configuration
Capture nuclear and mitochondrial features relevant to interpretation and maintenance.
Strain genotype and dependencies
Record measured ploidy, chromosome variation, relevant alleles, constructs and nutrient dependencies.
- What evidence establishes ploidy, aneuploidy or genetic heterogeneity in this culture? measurement
- Which auxotrophies, introduced constructs or mitochondrial changes affect cultivation and phenotype interpretation? definition
Reproductive capability
Separate vegetative propagation from strain-specific mating and sporulation behavior.
Mating and sporulation competence
Record mating-type configuration, switching behavior and evidence of successful mating or sporulation.
- What are the strain's MAT configuration and documented mating-type switching behavior? definition
- Under which tested conditions does this strain mate or produce viable spores? measurement
Carbon metabolism and growth Describe how the strain grows and partitions carbon under specified environmental conditions.
S. cerevisiae performance depends on substrate, oxygen availability, nutrient supply and strain background.
Fermentation and respiration
Capture measured carbon-use behavior without inferring metabolism from oxygen presence alone.
Condition-dependent carbon use
Associate growth, sugar consumption, ethanol production and respiratory evidence with the conditions of observation.
- Which carbon sources support growth or fermentation in this strain, and under what oxygen and concentration conditions? measurement
- What measurements distinguish fermentative, respiratory or mixed activity in the observed culture? measurement
Nutrients and stress
Represent the strain's nutritional requirements and responses to fermentation-relevant stresses.
Supported growth envelope
Record tested nutrient requirements and responses to temperature, acidity, ethanol and osmotic stress.
- Which nutrients or supplements are required under the intended oxygen regime and strain genotype? measurement
- What growth and survival evidence defines acceptable temperature, pH, ethanol and osmotic conditions for this use? action
Culture condition and continuity Assess the present population and maintain a traceable connection to its reference stock.
A correctly named strain can still be nonviable, contaminated, heterogeneous or altered during propagation.
Population condition
Distinguish biomass, viable cells, aggregation and contamination.
Viability, purity and aggregation
Interpret culture measurements using assay limitations, including budding cells, flocculation and mixed populations.
- What are the measured viable fraction and viable concentration, and how did counting account for buds or cell aggregates? measurement
- Which tests assessed bacterial contamination, other yeasts and unintended S. cerevisiae strains? measurement
Stock continuity
Track preservation, recovery and passage history against a reference culture.
Preservation and drift
Record handling history and checks for loss of defining genetic or performance traits.
- Which reference stock, preservation conditions and propagation history link to the current culture? provenance
- Which identity, genotype or performance checks must pass after recovery or repeated propagation? action
Use fitness and handling Translate strain evidence into decisions for a defined application and handling context.
Species identity alone cannot establish production performance, experimental validity or permission for a particular use.
Application performance
Connect the intended role to strain-specific acceptance criteria.
Role-specific acceptance
Evaluate traits such as gas production, fermentation completion, flocculation or experimental phenotype according to the actual task.
- Is the strain intended for baking, brewing, winemaking, another bioprocess or laboratory research, and which outcomes define success? definition
- Which representative-condition results establish that this culture meets those acceptance criteria? measurement
Handling and use status
Associate the exact strain and preparation with applicable handling assessments and use documentation.
Context-specific use decision
Distinguish live cultures, inactivated preparations and modified strains when assessing an intended use.
- Which documented handling assessment and use status apply to this exact strain, preparation and jurisdiction? provenance
- Do the intended exposure route, genetic modifications or culture condition require additional review before use? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- The supplied chemical-material context is inappropriate for this organism: strain identity, viability and culture conditions matter more than chemical purity or melting point.
- The kinds listed are overlapping functional strain groups, not formal taxonomic subdivisions; dimensions and performance vary with strain and conditions.
- This is recalled knowledge without source consultation; strain-specific safety claims and jurisdiction-specific regulatory status require verification.
- Which of these check these first hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Baking strains
- Ale-brewing strains
- Wine-fermentation strains
- Distilling and industrial ethanol strains
- Laboratory strains
- Probiotic strains commonly called Saccharomyces boulardii
- Which of these kinds and varieties hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- Scientific binomial - Saccharomyces cerevisiae - Identifies a fungal species, not a chemical substance or a particular commercial yeast preparation.
- NCBI Taxonomy - 4932 - Species-level taxonomy identifier.
- Laboratory strain designation - S288C - A widely used reference strain; findings about it do not necessarily describe every strain of the species.
- Which of these identifiers and schemes hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Leavening bread through carbon dioxide production.
- Producing alcoholic beverages through fermentation.
- Producing fuel and industrial ethanol.
- Serving as a model organism for genetics, cell biology and molecular biology.
- Producing recombinant proteins and other biotechnology products.
- Which of these real-world use hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Typical vegetative cell dimension - Approximately 3-10, depending on strain, growth conditions and cell-cycle stage - µm
- Reference haploid nuclear genome size - Approximately 12 - megabase pairs
- Reference haploid nuclear chromosome count - 16 - chromosomes
- Which of these typical measurements hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Fermentation can slow or stop because of nutrient limitation, unsuitable temperature, inhibitory compounds or ethanol stress.
- Contaminating microorganisms can alter fermentation performance and product quality.
- Uncontrolled fermentation in sealed containers can cause pressure buildup.
- Strain variation and genetic instability can reduce industrial consistency or experimental reproducibility.
- Rare opportunistic infections, including fungemia associated with probiotic strains, can occur in vulnerable patients.
- Which of these failure modes and hazards hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Traditional baking, brewing and winemaking practices use different locally selected strains.
- Requirements for food, feed, probiotic and genetically modified yeast products vary by jurisdiction and intended use.
- Which of these regional variation hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Yeast - Yeast describes a growth form shared by many fungi; Saccharomyces cerevisiae is one particular species.
- Saccharomyces pastorianus - The principal lager-brewing yeast is a hybrid involving Saccharomyces cerevisiae and Saccharomyces eubayanus, rather than simply a cold-growing strain of Saccharomyces cerevisiae.
- Saccharomyces boulardii - This name commonly denotes probiotic lineages classified within Saccharomyces cerevisiae; probiotic properties require strain-level identification.
- Baker's yeast - Baker's yeast denotes strains or preparations selected for baking, whereas the species includes many other strains and uses.
- Yeast extract - Yeast extract is a processed mixture of cellular constituents, not a living organism or fungal species.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of Saccharomyces cerevisiae this model covers, and on what evidence? provenance
What the second pass must settle
- Which authoritative taxonomic reference and identification criteria should anchor the registry entry and resolve ambiguous or hybrid isolates?
- How should strains marketed as Saccharomyces boulardii be represented under the chosen taxonomic authority without creating duplicate species models?
- Which physiological claims are sufficiently supported across S. cerevisiae strains to record at species level, and which must remain strain-specific?
- Which comparable assays and reference conditions should define growth, fermentation, viability and stress-response measurements?
- Which strain-specific handling and use-status sources are needed for the intended applications and jurisdictions?