Resuscitation-promoting factor (Rpf) terminates dormancy among diverse soil bacteria

Area of Science:

• Microbiology
• Biochemistry
• Ecology

Background:

• Microorganisms enter dormancy to survive harsh conditions.
• Resuscitation-promoting factor (Rpf) is an enzyme that helps bacteria exit dormancy.
• Understanding Rpf's role in soil bacteria is crucial for ecosystem functioning.

Purpose of the Study:

• To characterize Rpf from the soil bacterium *Micrococcus* KBS0714.
• To investigate the effects of this Rpf on the resuscitation of diverse dormant soil bacteria.
• To link Rpf's activity to bacterial functional traits and phylogeny.

Main Methods:

• Protein purification and enzymatic assays of *Micrococcus* KBS0714 Rpf.
• Site-directed mutagenesis and deletion analysis of Rpf.
• Live-cell resuscitation assays with diverse soil bacteria exposed to recombinant Rpf.

Main Results:

• *Micrococcus* KBS0714 Rpf exhibited high substrate affinity and required specific catalytic sites and structural motifs for activity.
• Rpf-induced resuscitation varied among bacterial strains, correlating with phylogeny and cell envelope composition.
• Rpf's effect was associated with functional traits like moisture niche and biofilm production.

Conclusions:

• Rpf from *Micrococcus* KBS0714 is a key factor in soil bacterial dormancy and resuscitation.
• Rpf activity is influenced by bacterial phylogeny and functional traits.
• These findings have implications for microbial population dynamics and ecosystem processes in soils.