Fermentation odor and bioprocess scale-up

During scaleup of Streptomyces avermitilis batch culture based on similarity of geometry, aeration and mixing conditions, the production of avermectins was proportional to the intensity of fermentation odor represented by geosmin. The active stimulatory role of odor component on antibiotic production was detected after addition of volatile compounds separated from the fermentation liquor by steam distillation.