Chlorella-Azospirillum Synthetic Mutualism

Community ID CommunityMech:000191

Ecological State ENGINEERED

Environment algal-bacterial laboratory culture
ENVO:01001405

A defined algal-bacterial synthetic mutualism pairing the freshwater green microalga Chlorella sorokiniana UTEX 2714 with the plant-growth-promoting bacterium Azospirillum brasilense Cd. The pair has been studied in co-immobilized alginate bead systems and related culture formats to test how nutrient availability shapes mutualistic population growth, tryptophan, thiamine, and indole-3-acetic acid exchange, starch accumulation, and algal-bacterial aggregation. The system is relevant to environmental biotechnology, microalgal biomass production, and algal-bacterial interaction design.

Taxonomy

Taxon	Ontology ID	Functional Roles	Abundance
Chlorella sorokiniana UTEX 2714	NCBITaxon:3076	PRIMARY_PRODUCER CROSS_FEEDER	N/A
doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO) "microalgae Chlorella sorokiniana UTEX 2714" doi:10.1093/femsec/fiw077 - SUPPORT (IN_VITRO) "The unicellular microalga C. sorokiniana (UTEX 2714"
Azospirillum brasilense Cd	NCBITaxon:192	SYNTROPHIC_PARTNER CROSS_FEEDER	N/A
doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO) "plant growth-promoting bacterium Azospirillum brasilense Cd" doi:10.1093/femsec/fiw077 - SUPPORT (IN_VITRO) "bacterium Azospirillum brasilense Cd (DSM 1843"

Ecological Interactions

Taxon

Cross-feeding

Mutualism

Syntrophy

Competition

Commensalism

Niche partitioning

Colonization facilitation

Strain competition

Predation

Nutrient-Modulated Synthetic Mutualism

MUTUALISM

Source Taxon: Chlorella sorokiniana UTEX 2714

Target Taxon: Azospirillum brasilense Cd

Biological Processes:

photosynthesis (GO:0015979)
biological process involved in interspecies interaction between organisms (GO:0044419)

Evidence

doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO)

"synthetic mutualism between C. sorokiniana and A. brasilense can be modulated"
doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO)

"Overall, populations of bacteria and microalgae were larger when co-immobilized."

Tryptophan, Thiamine, and IAA Exchange

CROSS_FEEDING

Source Taxon: Chlorella sorokiniana UTEX 2714

Target Taxon: Azospirillum brasilense Cd

Metabolites: L-tryptophan (CHEBI:16828), thiamine (CHEBI:18385), indole-3-acetic acid (CHEBI:16411)

Biological Processes:

indole-3-acetic acid biosynthetic process (GO:0009684)
tryptophan biosynthetic process (GO:0000162)
biological process involved in interspecies interaction between organisms (GO:0044419)

Evidence

doi:10.1093/femsec/fiw077 - SUPPORT (IN_VITRO)

"using tryptophan and thiamine released by the microalga"
doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO)

"production of signal molecules tryptophan and indole-3-acetic acid"

Co-Immobilization and Cell Aggregation

COLONIZATION_FACILITATION

Source Taxon: Azospirillum brasilense Cd

Target Taxon: Chlorella sorokiniana UTEX 2714

Biological Processes:

cell aggregation (GO:0098743)
biological process involved in interspecies interaction between organisms (GO:0044419)

Evidence

doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO)

"Formation of aggregates made of microalgae and bacteria occurred"
doi:10.1093/femsec/fiw077 - SUPPORT (IN_VITRO)

"Microorganisms were immobilized individually and co-immobilized in alginate beads"

IAA-Linked Starch Accumulation Response

MUTUALISM

Source Taxon: Azospirillum brasilense Cd

Target Taxon: Chlorella sorokiniana UTEX 2714

Metabolites: L-tryptophan (CHEBI:16828), indole-3-acetic acid (CHEBI:16411)

Biological Processes:

indole-3-acetic acid biosynthetic process (GO:0009684)
biological process involved in interspecies interaction between organisms (GO:0044419)

Evidence

doi:10.1016/j.resmic.2016.02.005 - SUPPORT (IN_VITRO)

"measured the relations between tryptophan production, the phytohormone indole-3-acetic acid"
doi:10.1016/j.resmic.2016.02.005 - SUPPORT (IN_VITRO)

"created by co-immobilization in alginate beads"

External Resources

Name	Repository	Resource ID
Exact-system publication - nutritional modulation of synthetic mutualism Primary exact-composition publication on how nutrient-rich, nitrogen-free, and carbon-free initial conditions affect C. sorokiniana UTEX 2714 and A. brasilense Cd synthetic mutualism.	OTHER	doi:10.1007/s00248-018-1282-1
doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO) "Chlorella sorokiniana UTEX 2714 and the plant growth-promoting bacterium Azospirillum brasilense Cd"
Exact-system publication - tryptophan, thiamine, and IAA exchange Exact-composition publication measuring tryptophan, thiamine, and indole-3-acetic acid exchange between C. sorokiniana and A. brasilense.	OTHER	doi:10.1093/femsec/fiw077
doi:10.1093/femsec/fiw077 - SUPPORT (IN_VITRO) "Chlorella sorokiniana and the plant growth-promoting bacterium"
Exact-system publication - starch response under heterotrophic conditions Exact-composition follow-up publication linking tryptophan, IAA, and starch accumulation in the C. sorokiniana-A. brasilense synthetic mutualism.	OTHER	doi:10.1016/j.resmic.2016.02.005
doi:10.1016/j.resmic.2016.02.005 - SUPPORT (IN_VITRO) "synthetic mutualism between the microalgae Chlorella sorokiniana and the microalgae growth-promoting bacteria Azospirillum brasilense"
Related predecessor publication - Chlorella vulgaris and Azospirillum brasilense alginate beads Related alginate bead coculture precedent using Chlorella vulgaris and A. brasilense; included as historical context, not as exact species composition evidence for this C. sorokiniana record.	OTHER	doi:10.1128/AEM.66.4.1527-1531.2000
doi:10.1128/AEM.66.4.1527-1531.2000 - PARTIAL (IN_VITRO) "Chlorella vulgaris and the plant-growth-promoting bacterium Azospirillum brasilense"
NCBI Taxonomy - Chlorella sorokiniana NCBI Taxonomy record for Chlorella sorokiniana.	OTHER	NCBITaxon:3076
NCBI Taxonomy - Azospirillum brasilense NCBI Taxonomy record for Azospirillum brasilense.	OTHER	NCBITaxon:192

Environmental Factors

Factor	Value	Unit
Initial nitrogen and carbon availability	nutrient-rich, nitrogen-free, and carbon-free initial conditions	N/A
doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO) "three different nutritional conditions during the initial 12 h" doi:10.1007/s00248-018-1282-1 - SUPPORT (IN_VITRO) "presence or absence of nitrogen and carbon in the medium"
Co-immobilized alginate beads	co-immobilized algal-bacterial bead culture	N/A
doi:10.1093/femsec/fiw077 - SUPPORT (IN_VITRO) "beads of 2 mm diameter were formed"
Light and aerobic culture context	illuminated aerobic laboratory culture	N/A
doi:10.1093/femsec/fiw077 - SUPPORT (IN_VITRO) "60 umol photon m-2 s-1" doi:10.1016/j.resmic.2016.02.005 - SUPPORT (IN_VITRO) "dark, heterotrophic and aerobic growth conditions"

Growth Media

Chlorella-Azospirillum alginate bead coculture assay

Atmosphere AEROBIC

Composition

Component	Concentration	Unit	CHEBI
L-tryptophan	N/A	N/A	CHEBI:16828
indole-3-acetic acid	N/A	N/A	CHEBI:16411

Preparation notes: Publications support alginate bead immobilization and nutrient-perturbation assays for the C. sorokiniana UTEX 2714 and A. brasilense Cd pair. Detailed medium composition is not asserted here beyond the reported nutrient-rich, nitrogen-free, and carbon-free condition classes.

Evidence

doi:10.1007/s00248-018-1282-1

"nutrient-rich medium"

doi:10.1007/s00248-018-1282-1

"nitrogen-free (N-free) or carbon-free (C-free) media"