"Cold Spring"), Tran Municipality [bg], Pernik Province, Bulgaria.

In the microbiological laboratory of Professor Léon Massol in Geneva, he discovered that a certain strain of bacillus is the basis of yogurt.

In the 1950s, the state-owned yogurt company patented and promoted a specific blend of bacterial strains to create an "official Bulgarian yoghurt".

[2] Apart from the discovery of Lactobacillus bulgaricus, Grigorov contributed to the creation of a tuberculosis treatment in 1906, along with Albert Calmette.

Through his scientific experiments in-vitro and in-vivo on lab animals and later on human patients, Grigorov demonstrated the healing effect of Penicillium fungi in the treatment of tuberculosis.