Pythium oligandrum is a microorganism that taxonomically belongs to the kingdom Chromalveolata and the family Oomycetes. Charles Drechsler (1943) was the first to describe Pythium oligandrum as the mycoparasite of the wide range of phytopathogenic fungal microorganisms. During the 1970’s, Dr. Dáša Veselý focused his research on development of Pythium oligandrum for plant protection uses. In the 1990’s, the company Biopreparáty, spol. s r.o. succeeded to formulate, register and commercialize Pythium oligandrum, strain M1, as the biological fungicide.