Controlling of flagellates and ciliates contaminations in Chlorella mass culture

Abstract

Background: Flagellates and ciliates are two common bio-contaminants which frequently cause biomass losses in Chlorella mass culture. Efficient and targeted ways are required to control contaminations in Chlorella mass cultivation aiming for biofuel production especially. Results: Five surfactants were tested for its ability to control bio-contaminations in Chlorella culture. All five surfactants were able to eliminate the contaminants at a proper concentration. Particularly the minimal effective concentrations of sodium dodecyl benzene sulfonate (SDBS) to completely eliminate Poterioochromonas sp. and Hemiurosomoida sp. were 8 mg L−1 and 10 mg L−1, respectively, yet the photosynthesis and viability of Chlorella was not significantly affected. These results were further validated in Chlorella mass cultures in 5, 20, and 200 m2 raceway ponds. Conclusions: A chemical method using 10 mg L-1 SDBS as pesticide to control flagellates or ciliates contamination in Chlorella mass culture was proposed. The method helps for a sustained microalgae biomass production and utilization, especially for biofuel production.