Chlorellin is the first antibiotic substance obtained from autotrophic
organisms. In 1940 Pratt found that antibacterial substances are produced in
cultures of the algae Chlorella pyrenoidosa and Chlorella vulgaris. In 1944 a group
of botanists (Pratt et al.) and pharmacologists undertook studies on the properties
of this substance, which was given the name chlorellin.