Continuous biomass and lipid production from local chlorella-bacteria consortium in raw wastewater using volatile fatty acids.

ABSTRACT

OBJECTIVES: To evaluate mixotrophic cultivation of microalgae-bacteria consortium in raw wastewater by stepwise addition of fermented effluent containing volatile fatty acids (VFAs). RESULTS: Stepwise increase of VFAs enhanced algal biomass and lipid production, ammonia and phosphate removals. The highest biomass and lipid yield were 1.94 g L-1 and 310 mg L-1 when the addition of fermented effluent containing VFAs increased to 30% (v/v). With the same cultivation conditions, the maximum removals efficiency of ammonia and phosphate were 26.4 and 11.3 mg L-1 d-1. Bacterial diversities increased with the increasing concentration of VFAs and their communities were identified as phyla Actinobacteria, Bacteroidetes, Cyanobacteria and Proteobacteria. CONCLUSIONS: Although bacterial quantities increased with algae growth concurrently, the objective of culturing microalgae-bacteria consortium in raw wastewater without sterilization to produce biomass and lipid yield still can be realized.