Method of treating bacterial contamination in a microalgae culture with ph shock

Abstract

Methods of treating contamination, particularly bacterial contamination, in an open culture of microalgae with organic carbon are described herein. The methods comprise reducing the pH of a culture for a period of time and then raising the pH of the culture, wherein the culture comprises the presence of a first acid and the culture is contacted with a second acid to reduce the culture pH from a first pH value to a second pH value. The culture is maintained at the second pH value for at least 5 minutes before the culture pH is raised from the second pH value by contact with a base.