Production of Antibiotic Substances 277 



prodigiosin, nisin, and colicincs. The soil fungi have yielded a large 

 number of antibiotics, most important of which is penicillin; others 

 include mycophenolic acid, gliotoxin, clavacin, gladiolic acid, che- 



FiG. 109. Streptomyces griseus, streptomycin-producing strain. Vegetati\e and 



aerial mycelium. 



tomin, penicillic acid, fumigatin, and fumigacin (Table 63). The 

 actinomycetes have already yielded more than seventy antibiotics, 

 some of which, notably streptomycin, chloramphenicol, aureomycin, 

 terramycin, and neomycin, have found extensive practical applica- 

 tion. Others include actinomycin, streptothricin, actidione, strep- 

 tocin, xantomycin, viomycin, antimycin, fungicidin, and fradicin. 



