From Atlas Obscura's description on YouTube:

According to Karl De Smedt, the man behind the world’s only sourdough library, sourdough belongs to the entire world. Burbling away in refrigerators are over 100 sourdough starters from around the globe, all chosen due to their renown, unusual origins, and often, estimated age.

Smedt refreshes the starters with the original flours as well. That's dedication.