An Enterotoxin-Like Binary Protein from Pseudomonas protegens with Potent Nematicidal Activity

Area of Science:

• Microbiology
• Biochemistry
• Toxicology

Background:

• Soil nematodes are preyed upon by soil microbes.
• Some soil bacteria possess mechanisms to deter predation by nematodes.

Purpose of the Study:

• To identify and characterize a novel nematicidal protein from *Pseudomonas protegens*.
• To investigate the activity and specificity of the identified protein against various nematodes.

Main Methods:

• Screening of *Pseudomonas protegens* strains for nematicidal activity.
• Protein purification and identification of the binary protein Pp-ANP.
• Testing Pp-ANP activity against *Caenorhabditis elegans* and other nematode species, as well as insects and fungi.

Main Results:

• Identified Pp-ANP, a binary protein from *Pseudomonas protegens* 15G2, with potent nematicidal activity.
• Pp-ANP inhibits *C. elegans* growth and development, arresting larvae and killing older worms.
• The toxin demonstrated specific activity against four free-living nematode species, with no observed effects on insects or fungi.
• Pp-ANP subunits (Pp-ANP1a and Pp-ANP2a) are active upon reconstitution and Pp-ANP2a shares structural similarities with bacterial enterotoxins.

Conclusions:

• Pp-ANP is a novel enterotoxin-like binary toxin with potent and specific activity against nematodes.
• The distinct characteristics of Pp-ANP differentiate it from known toxins like cholera toxin and *E. coli* heat-labile enterotoxin.
• Pp-ANP holds promise for applications in controlling parasitic nematodes and warrants further research into its mechanism of action.