Abstract: In various aspects, the present invention is directed to a scalable method of producing rhamnolipids by bacterial fermentation with higher product concentrations, yields and productivities and preventing excessive foaming during the cell growth phase when the cell respiration rate is higher. It has been found that by slowing the growth rate of the bacteria by altering the ratio of the nitrogen source to the non-nitrogen source in the initial fermentation medium and supplementing the nitrogen source, excessive foaming in the growth phase can be prevented. Further, by using the non-nitrogen source as the limiting nutrient that initiates the stationary phase and then supplementing fermentation broth with the nitrogen and carbon sources, the length of the standing phase, and with it the time during which rhamnolipid production occurs can be greatly extended.

Abstract: In various aspects, the present invention is directed to a scalable method of producing rhamnolipids by bacterial fermentation with higher product concentrations, yields and productivities and preventing excessive foaming during the cell growth phase when the cell respiration rate is higher. It has been found that by slowing the growth rate of the bacteria by altering the ratio of the nitrogen source to the non-nitrogen source in the initial fermentation medium and supplementing the nitrogen source, excessive foaming in the growth phase can be prevented. Further, by using the non-nitrogen source as the limiting nutrient that initiates the stationary phase and then supplementing fermentation broth with the nitrogen and carbon sources, the length of the standing phase, and with it the time during which rhamnolipid production occurs can be greatly extended.