Nocardia amarae grown in a liquid medium induced coalescence of emulsions which differed in type, composition of the organic phase, and structure of stabilizing emulsifiers. De-emulsifying activity varied with the type of growth medium, culture age, and postharvest treatment. Based on extraction and degradation studies, it was concluded that de-emulsifying properties are due to the bacterial cell surface. Thus, bacteria may provide a new source of de-emulsifying agents.