Microbial generalist or specialist: Intraspecific variation and dormancy potential matter

Area of Science:

• Microbial ecology
• Evolutionary biology
• Soil science

Background:

• Microbial generalists and specialists shape soil community dynamics.
• Mechanisms defining microbial generalist vs. specialist roles are unclear.

Purpose of the Study:

• Investigate intraspecific variation in bacterial generalists and specialists.
• Understand how niche breadth influences microbial community stability and assembly.

Main Methods:

• Collected soil samples nationwide.
• Identified bacterial generalists and specialists by niche breadth (OTU level).
• Measured intraspecific variation (single-nucleotide differences at zero-radius OTU level).

Main Results:

• Generalists showed significantly higher intraspecific variation than specialists.
• Higher intraspecific variation in generalists correlated with wider niche breadth and lower variability.
• Generalists displayed higher asynchrony, varied niche preferences, greater dormancy potential, and stronger stochastic assembly signatures.
• Generalists exhibited higher diversification and transition rates, enhancing environmental adaptability.

Conclusions:

• Intraspecific variation and dormancy potential are crucial for microbial generalist stability.
• Generalists play a significant role in microbial community assembly and adaptation to environmental change.
• This study enhances understanding of assembly rules and evolutionary roles of bacterial generalists and specialists.