Molds and cellular slime molds
Raper joined the US Department of Agriculture in 1929 and worked with mycologist Charles Thom. In 1935 he described Dictyostelium discoideum and investigated its growth and development; he received his Harvard doctorate in 1936. His later collaborations with Thom produced major manuals of Aspergillus and Penicillium.
References: [1]
Screening penicillin strains
At Peoria’s Northern Regional Research Laboratory from 1940, Raper organized a microbial culture collection. After Florey and Heatley’s 1941 visit, his role included testing cultures for penicillin production. Productive strains were shared with collaborators, including Wisconsin researchers, whose further selection and mutation work complemented improvements in media and fermentation.
Work at Wisconsin
Raper moved to the University of Wisconsin–Madison in 1953 with appointments in bacteriology and botany. He continued linking field collection and classification of cellular slime molds with experimental studies of development, remaining active after retirement in 1979.
References: [1]