Brachionus plicatilis culture filtrate promotes sedimentation and harvesting of Chlorella

Abstract

Harvesting of microalgae has been one of the major bottlenecks for commercial use. Sedimentation of the microalgae cells can facilitate the harvesting process, thus reducing the cost of yielding algae-based industrial products. We investigated the potential of Brachionus plicatilis and Artemia salina culture filtrates for promoting Chlorella sedimentation. B. plicatilis culture filtrate demonstrated the potential for promoting Chlorella sedimenta- tion, the sedimentation rate of Chlorella cells treated with the filtrate increased to 53.4 % within 24 h (20 % higher than control). The secretion of soluble extracellular polymeric substances was significantly increased in the Chlorella culture treated with either filtrate. The PSII quantum efficiency and growth rate in B. plicatilis culture treated Chlorella were not significantly affected. As the presented method is non-toxic and non-pathogenic, it may be an alternative for facilitating the harvesting of unicellular microalgae species used in the pharmaceutical sector and as food supplements.