The invention relates to a microorganism from the species Lysobacter enzymogenes, having nematicidal activity and the ability to promote plant growth. The invention also provides methods for obtaining a biomass of said microorganism, as well as methods for biologically controlling nematodes, for treating and preventing plant infection caused by nematodes, and for promoting plant growth based on the use of said microorganism or of phytosanitary products obtained therefrom.