Utilization of oleuropein by microorganisms associated with olive fermentations

Oleuropein, the bitter glucoside of olives, and its hydrolysis products can possess antibacterial action. However, there is no information on the possible utilization of this polyphenolic compound; therefore studies have been made to assess its utilization as a major source of carbon. Various microorganisms associated with fermentation of olives (both desirable lactic acid bacteria and spoilage organisms) did use oleuropein, many without a significant delay in growth resulting in the appearance of a strong visible turbidity. Although the increase in oleuropein from 0.2 to 0.4% (w/v) had little or no effect on the spoilage organisms, the additional glucoside caused a delay in development of growth with some of the lactic acid bacteria. However, all of the latter cultures tested eventually grew and developed strong visible turbidity.