The study of micro-organisms in Britain in the early twentieth century was dominated by medical concerns, with little support for non-medical research. This paper examines the way in which microbes came to have a place in industrial contexts in the 1920s and early 1930s. Their industrial capacity was only properly recognized during World War I, with the development of fermentation processes to make required organic chemicals. Post-war research sponsored by chemical and food industries and the D.S.I.R. established the industrial significance (...) of microbes. The primary focus here is the D.S.I.R. work which aimed to pull microbes away from medical concerns and promote the role of microbes in British industry. (shrink)