Drew S W, Winstanley D J, Demain A L
Appl Environ Microbiol. 1976 Jan;31(1):143-5. doi: 10.1128/aem.31.1.143-145.1976.
DL-Norleucine, which is known to replace methionine for stimulation of cephalosporin C formation, also mimics methionine's effect on arthrospore formation. Thus, hyphal fragmentation, like antibiotic biosynthesis, is divorced from a sulfur donation role.