From external-input sensitivity to resident persistence: community assembly in a sink p-trap model

Area of Science:

• Microbial ecology
• Environmental microbiology
• Community assembly

Background:

• Microbial habitats receiving repeated external input may not be permanently shaped by it.
• Local retention can allow resident microbial communities to establish and dominate over time.

Purpose of the Study:

• To investigate microbial community assembly during initial establishment in new habitats.
• To determine the influence of repeated external input versus local history on microbial community development in sink p-traps.

Main Methods:

• Utilized a controlled bench-scale sink p-trap system.
• Introduced repeated handwashing-water input to experimental p-traps.
• Compared microbial succession in treated p-traps against a tap-water control.

Main Results:

• Treated p-traps exhibited successional changes towards resident-like states.
• External input had the most significant influence early in succession.
• The p-trap's prior state became a stronger predictor of community composition over time.
• Post-flush community trajectories showed a return towards pre-flush states.

Conclusions:

• Repeated microbial inoculation does not guarantee sustained external influence in retentive habitats.
• Established microbial communities in retentive habitats are shaped more by local history than ongoing external input.
• Microbial habitats can transition from sensitivity to external factors to persistence driven by local conditions.