This essay explores connections between bacteriology and the disciplinary evolution of biochemistry in this country during the 1930s. Many features of intermediary metabolism, a central component of biochemistry, originated as attempts to answer fundamental bacteriological questions. Thus, many bacteriologists altered their research programs to answer these questions. In so doing they changed their disciplinary focus from bacteriology to biochemistry. Chester Hamlin Werkman's (1893-1962) Iowa State career illustrates the research perspective that many bacteriologists adopted. As a junior faculty member in the (...) Bacteriology Department in the late 1920s, Werkman faced a powerful professional dilemma: establishing a research identity that distinguished him from his colleagues with flourishing national and international reputations. His solution was to radically alter his research program from traditional bacteriology to a biochemistry program, which reflected the influence of the Dutch microbiologist/biochemist, Albert Jan Kluyver (1888-1956). Werkman was extremely successful in this career change. His laboratory made significant contributions to biochemistry, and Werkman achieved a notable degree of personal success. His career began in the shadow of his departmental bacteriological colleagues; within a decade he became the department's dominant research figure, as a biochemist. Werkman's personal success, however, had profound consequences for the disciplinary future of bacteriology at Iowa State. (shrink)