Natamycin or Tennectin-E235 is a natural antibiotic produced by the bacterium Streptomyces natalensis (the genus streptomyces actinobacteria). It is a fungicide (and therefore a pesticide) that is produced industrially as a pharmaceutical product and as a food additive.
It is a polyene macrolide used as drug including against the keratitis, and specially of Aspergillus and Fusarium corneal infections.