- cross-feeding
- metabolite exchange
- syntrophy
- mycorrhizal exchange
- photosymbiosis
- gut microbial fermentation
- partner-mediated electron transfer
Operational definition
Dependency and acquisition strategy.
Resource acquisition in which another living system captures, transforms, concentrates, transports, or releases a substance that the focal system then uses.
Examples include:
- microbial cross-feeding;
- photosynthate transfer from a symbiont;
- mycorrhizal nutrient delivery;
- gut-microbial fermentation products;
- syntrophic removal of an inhibitory product;
- interspecies electron transfer.
The defining criterion is that the partner’s metabolism materially changes resource accessibility to the focal system. Membrane transport and endocytosis distinguish dissolved molecular uptake from particulate ingestion, while cross-feeding extends acquisition across organismal boundaries. (NCBI)