The present invention provides a fermentation process for producing lipstatin comprising the steps of: a) preparing a fermentation medium containing a lipstatin-producing microorganism comprising an oil and an assimilable carbon source, wherein the wt/wt ratio of oil and assimilable carbon source is regulated to achieve an optimal lipstatin biosynthesis by the microorganism; and b) feeding the fermentation medium with an emulsifier, wherein the emulsifier provides an optimal viscosity for the fermentation medium and optimal pH during the fermentation to permit fermentation for lipstatin production. The disclosed process also provides a process for extracting a lipstatin from a fermentation broth.