Lecture 13:

Microbial Cross-Feeding

An interaction where metabolic byproducts of one microorganism (producer) serve as nutrients for another (receiver or beneficiary).

Assemblage of microbial communities

The formation of microbial communities shaped by deterministic and stochastic processes. Can be created through genetic diversity or dispersal. The amount of members depends on genetic drift, ongoing dispersal, and natural selection.

Deterministic processes

Factors based on specific conditions that influence microbiome assembly.

Stochastic processes

Random fluctuations that affect the composition of microbial communities.

Metabolite Transfer

The transfer of metabolites among microbes that can occur through direct contact or environmental release.

Interspecies Hydrogen Transfer

Interaction between hydrogen-producing and hydrogen-consuming bacteria critical for metabolic processes in anaerobic environments.

Butyrate Production

The generation of butyrate, an important molecule for gut health, through cross-feeding between Bifidobacterium and butyrate-producing bacteria.

Metabolite Exchange Score (MES)

A score inferred from metabolic models to compare interactions in healthy versus diseased microbial states.

Coculture experiments

Experiments involving the growth of two different bacterial types together to observe cross-feeding interactions.

Flux-Balance Analysis

A modeling approach to predict optimal microbial species combinations based on nutrient sharing and best growth together.

Crohn’s Disease

A condition linked to specific alterations in cross-feeding interactions, such as changes in hydrogen sulfide production.

Evolutionary Models

Hypothetical models suggesting microbial strains lose functions to improve growth efficiency and cross-feeding.

Genetic Adaptations

Distinct gene clusters responsible for substrate utilization that indicate evolutionary support for cross-feeding.

Microbiome Stability

The ability of microbial communities to maintain function and stability through interactions like cross-feeding.

Ecological Implications of Cross-Feeding

Cross-feeding contributes to energy conservation and growth yield in various ecosystems.