Chlorella-Rhizobium Bioflocculation

Ecological State ENGINEERED

Environment wastewater treatment plant
ENVO:00002001

Source File Chlorella_Rhizobium_Bioflocculation.yaml

A co-culture system pairing the microalgae Chlorella vulgaris with the bioflocculant-producing bacterium Rhizobium radiobacter F2 for enhanced algal harvesting in wastewater treatment applications. The bacterium produces extracellular polysaccharide bioflocculants that induce aggregation and flocculation of algal cells, enabling efficient biomass recovery for biofuel production. This bioflocculation approach avoids the negative effects of traditional chemical flocculants and provides a cost-effective, environmentally friendly method for microalgae harvesting, with flocculation efficiency improving from 0.2% (axenic algae) to >90% with bacterial co-culture.

Taxonomy

Taxon	Ontology ID	Functional Roles	Abundance
Chlorella vulgaris	NCBITaxon:3077	PRIMARY_PRODUCER	N/A
Rhizobium radiobacter F2	NCBITaxon:358	PRIMARY_DEGRADER	N/A

Ecological Interactions

Photosynthetic Carbon Fixation

COMMENSALISM

Source Taxon: Chlorella vulgaris

Biological Processes:

photosynthesis (GO:0015979)
lipid biosynthetic process (GO:0008610)

Downstream Effects:

→ Bioflocculant Production and Cell Aggregation

Evidence

doi:10.1111/jbm.12334 - SUPPORT (IN_VITRO)

"enhancing microalgae harvesting and lipid content"

Bioflocculant Production and Cell Aggregation

MUTUALISM

Source Taxon: Rhizobium radiobacter F2

Metabolites: polysaccharide (CHEBI:18154)

Biological Processes:

extracellular polysaccharide biosynthetic process (GO:0045226)
cell aggregation (GO:0098743)
single-species biofilm formation (GO:0044010)

Downstream Effects:

→ Algal Biomass Harvesting

Evidence

doi:10.1111/jbm.12334 - SUPPORT (IN_VITRO)

"Bioflocculant-producing microbes are environmentally friendly functional materials that avoid the negative effects of traditional chemical flocculants"

Algal Biomass Harvesting

MUTUALISM

Source Taxon: Chlorella vulgaris

Biological Processes:

cell aggregation (GO:0098743)

Evidence

doi:10.1111/jbm.12334 - SUPPORT (IN_VITRO)

"provided new insights into microalgae harvesting and cost-effective production of microalgal bioproducts"

Environmental Factors

Factor	Value	Unit
Light	Required for photosynthesis	N/A
Glucose concentration	Optimized concentration	g/L (specific value determined by response surface methodology)
Bacteria-to-algae inoculation ratio	Optimized ratio	N/A
Co-culture time	Optimized duration	hours or days