Minimizing co-growth as a broad predictor of community robustness

Area of Science:

• Ecology
• Microbiology
• Systems Biology

Background:

• Microbial communities are dynamic, not static, exhibiting life cycles that alter ecological interactions.
• Existing ecological theories primarily address coexistence with fixed interactions, lacking predictors for dynamic communities.
• Robustness in microbial communities undergoing growth and dispersal cycles requires new quantitative measures.

Purpose of the Study:

• To identify simple quantitative predictors of robustness in dynamically maturing microbial communities.
• To investigate the role of temporal dynamics in microbial community stability and persistence.
• To determine if a common feature predicts robustness across diverse community maturation models.

Main Methods:

• Modeled microbial community maturation using scenarios like chemotactic spatial patterning and cross-feeding with toxicity.
• Introduced a phenomenological many-species model with defined growth trajectories.
• Quantified community robustness by measuring persistence under stochastic reseeding and analyzing temporal co-growth.

Main Results:

• Temporal co-growth, the overlap in species' growth phases, emerged as a key predictor of community robustness.
• Communities with distinct, non-overlapping species growth periods showed significantly longer persistence than those with overlapping growth.
• Community lifetime increased exponentially as temporal co-growth decreased across all modeled systems.

Conclusions:

• Temporal co-growth is a unifying quantitative feature of robust, dynamically maturing microbial communities.
• Mechanisms promoting robustness, including spatial organization and metabolic interactions, function by reducing temporal growth overlap.
• Minimizing temporal co-growth may serve as a general ecological principle for enhancing community robustness.