Any of various filamentous,mostly anaerobic microorganisms of the genus Actinomyces,which includes the causative agents of actinomycosis.

• 肉毒杆菌一种（肉毒梭状芽孢杆菌）属的厌氧型钩形细菌，能分泌肉毒毒素，寄生于土壤中