A rationally designed two-member artificial consortium composed of Clostridium phytofermentans ISDg, currently represented in NCBI Taxonomy as Lachnoclostridium phytofermentans ISDg, and Escherichia coli K-12 MG1655. The community was built to improve conversion of cellulose-derived sugars into ethanol, biomass, and other bioproduct-relevant outputs through division of labor between a cellulolytic obligate anaerobe and a facultative anaerobe. It is DOE-relevant because it models consolidated lignocellulosic bioprocessing, cellobiose conversion, biofilm oxygen partitioning, and cross-feeding mechanisms that can improve cellulosic fuel and chemical production.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Clostridium phytofermentans ISDg — ontology label: Lachnoclostridium phytofermentans ISDg | NCBITaxon:357809 · TaxonMech · TraitMech |
PRIMARY_DEGRADER
|
COMMON |
|
|||
| Escherichia coli K-12 MG1655 — ontology label: Escherichia coli str. K-12 substr. MG1655 | NCBITaxon:511145 · TaxonMech · TraitMech |
SECONDARY_FERMENTER
CROSS_FEEDER
|
COMMON |
|
|||
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.
Cellobiose Hydrolysis And Glucose Scavenging Feedback
CROSS_FEEDINGC. phytofermentans extracellular cellobiase hydrolyzes cellobiose to glucose, supporting E. coli cross-feeding. Glucose-addition and spent-medium enzyme assays support inhibitory feedback. PARTIAL - relief through E. coli glucose consumption is the proposed consortium mechanism; its regulation and contribution to each outcome are not selectively resolved. These consortium experiments use cellobiose, not direct polymer-cellulose conversion.
Source Taxon: Clostridium phytofermentans ISDg
Target Taxon: Escherichia coli K-12 MG1655
Metabolites: cellobiose (CHEBI:17057 · MediaIngredientMech · CMMMech), glucose (CHEBI:17234 · MediaIngredientMech · CMMMech)
Biological Processes:
- fermentation (GO:0006113 · PathwayMech)
PARTIAL - glucose scavenging can relieve inhibition and sustain cellobiose conversion, consistent with glucose-addition, extracellular-enzyme and coculture comparisons. This supports the planktonic conversion model, not a direct measurement of biofilm ethanol output.
Evidence
-
PMID:33268782 - PARTIAL (IN_VITRO)"E. coli consumed inhibitory byproducts from cellobiose catabolism"
-
PMID:33268782 - SUPPORT (IN_VITRO)"released cellobiase enzyme which hydrolyzed cellobiose into glucose extracellularly"
Reciprocal Necromass-Supported Partner Growth
CROSS_FEEDINGAdded C. phytofermentans necromass supports aerobic E. coli growth, while filtered sonicated E. coli necromass enhances anaerobic C. phytofermentans growth. CFU measurements separately support better C. phytofermentans viability in coculture. PARTIAL - peptide mediation and the contribution of endogenous biomass turnover within intact consortia remain proposed; the reciprocal effects were tested in distinct assays.
Participating Taxa: Clostridium phytofermentans ISDg, Escherichia coli K-12 MG1655
Metabolites: peptide (CHEBI:16670 · MediaIngredientMech · CMMMech)
PARTIAL - necromass-addition controls support resource recovery as a contributor to partner growth and consortium biomass. They do not isolate its contribution to all planktonic products or establish biofilm ethanol production.
Evidence
-
PMID:33268782 - SUPPORT (IN_VITRO)"E. coli necromass enhanced C. phytofermentans growth"
-
PMID:33268782 - SUPPORT (IN_VITRO)"C. phytofermentans necromass aided E. coli growth"
Biofilm Oxygen Partitioning
Oxygen microprofiles and species distributions support E. coli respiration maintaining an anoxic region after biofilms first grow anoxically. Fully oxic inoculation did not yield the enhanced consortium phenotype. PARTIAL - qPCR-based cell equivalents and spatial persistence do not alone measure viability or establish a colonization-facilitation effect.
Source Taxon: Escherichia coli K-12 MG1655
Target Taxon: Clostridium phytofermentans ISDg
Metabolites: oxygen (CHEBI:15379 · MediaIngredientMech · CMMMech)
Biological Processes:
- biofilm formation (GO:0042710 · PathwayMech)
PARTIAL - biological oxygen consumption helps preserve an anoxic region after the anoxic-to-oxic transition and supports the biofilm biomass response. It is not a demonstrated driver of biofilm ethanol output, which was not directly measured.
Evidence
-
PMID:33268782 - SUPPORT (IN_VITRO)"E. coli consuming O2, creating an anoxic environment for C. phytofermentans"
-
PMID:33268782 - SUPPORT (IN_VITRO)"C. phytofermentans resided primarily in the anoxic bottom of the biofilm"
Measured Planktonic Conversion and Biofilm Biomass Outcomes
Anoxic planktonic coculture depleted more cellobiose and glycerol and produced more ethanol and biomass than the summed monocultures. Anoxic-to-oxic biofilms accumulated more total biomass plus extracellular material; their cellobiose use and ethanol output were not directly measured. These condition-specific outcomes do not by themselves establish each mechanism or constitute a separate syntrophy process.
Participating Taxa: Clostridium phytofermentans ISDg, Escherichia coli K-12 MG1655
Metabolites: cellobiose (CHEBI:17057 · MediaIngredientMech · CMMMech), glucose (CHEBI:17234 · MediaIngredientMech · CMMMech), ethanol (CHEBI:16236 · MediaIngredientMech · CMMMech)
Biological Processes:
- biofilm formation (GO:0042710 · PathwayMech)
Evidence
-
PMID:33268782 - SUPPORT (IN_VITRO)"enhanced substrate depletion, enhanced ethanol secretion, and enhanced biomass production as compared to monocultures"
Associated Datasets
| Dataset | Type | Repository | Accession |
|---|---|---|---|
|
Lachnoclostridium phytofermentans ISDg genome BioProject
NCBI BioProject for the complete genome of the C. phytofermentans ISDg member. |
GENOMICS | NCBI_BIOPROJECT | PRJNA16184 |
|
Escherichia coli K-12 MG1655 reference genome
Reference genome assembly for the E. coli K-12 MG1655 member. |
GENOMICS | OTHER | GCA_000005845.2 |
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN How much does each exchange mechanism contribute to viable biofilm biomass and product formation?
Glucose and necromass interventions support specific mechanisms, while oxygen profiles show a protected region after anoxic establishment. Partner-resolved transfer and viability assays would separate contributions. Direct biofilm substrate/product measurements are needed before assigning its inferred ethanol and cellobiose outcomes to these arrows.
Attaches to: ecological_interactions#Cellobiose Hydrolysis And Glucose Scavenging Feedback, ecological_interactions#Reciprocal Necromass-Supported Partner Growth, ecological_interactions#Biofilm Oxygen Partitioning, ecological_interactions#Measured Planktonic Conversion and Biofilm Biomass Outcomes
External Resources
| Name | Repository | Resource ID |
|---|---|---|
|
Primary publication - artificial cellobiose biofilm consortium
PubMed record for the primary publication reporting the C. phytofermentans and E. coli artificial consortium. |
OTHER | PMID:33268782 |
|
||
|
Full-text article - npj Biofilms and Microbiomes
Open-access full text containing methods, medium recipe, biofilm assays, and mechanistic interpretation for the exact two-member consortium. |
OTHER | doi:10.1038/s41522-020-00170-8 |
|
||
Environmental Factors
| Factor | Value | Unit |
|---|---|---|
| Modified GS-2 medium | mGS-2 | N/A |
|
||
| Temperature | 37 | C |
|
||
| Anoxic and oxic biofilm regimes | anoxic, oxic, and anoxic-to-oxic switch | N/A |
|
||
Growth Media
Cross-Mech Suite Links
Explore related entities across the CultureBotAI X-Mech knowledge bases: