Clostridial neurotoxins (CNTs) are the deadliest toxins known and the causative agents of botulism and tetanus. Despite their structural and functional complexity, no CNT homologs are currently known outside
Clostridium. Here, we report the first homologs of ClostridiumCNTs within the genome of the rice fermentation organism Weissella oryzaeSG25. One gene in W. oryzaeS25 encodes a protein with a four‐domain architecture and HExxH protease motif common to botulinum neurotoxins (BoNTs). An adjacent gene with partial similarity to CNTs is also present, and both genes seem to have been laterally transferred into the W. oryzaegenome from an unknown source. Identification of mobile, CNT‐related genes outside of Clostridiumhas implications for our understanding of the evolution of this important toxin family.