Cultivation of microalgae using anaerobically digested effluent from kitchen waste as a nutrient source for biodiesel production

Anaerobically digested effluent from kitchen waste (ADE-KW) is a potential medium for microalgae cultivation because it contains abundant nutrients. In this study, ADE-KW was utilized to cultivate the isolated microalgae Chlorella sorokiniana SDEC-18 and Scenedesmus SDEC-8, which showed optimal biomass productions of 0.42 g/L and 0.55 g/L, respectively, with 1/15 diluted ADE-KW. The lipid contents of Chlorella sorokiniana SDEC-18 (30.27-41.69%) and Scenedesmus SDEC-8 (35.97-47.39%) in this medium had obvious advantages over the controls grown in BG11 medium. The reason is that unbalanced nutrient and organic carbon levels in ADE-KW stimulate microalgae to turn more photosynthetic flow of carbon and energy from protein and carbohydrate into the biosynthesis of lipid than that in usual media. Moreover, this study showcased a proof-of-concept for the production of ideal biodiesel with desirable properties from microalgae under the cultivation of ADE-KW. In a large-scale experiment with K2HPO4 addition, the biomass and lipid productivity of Scenedesmus SDEC-8 were both promoted significantly (by factors of 2.27 and 1.08, respectively) by adding K2HPO4 to the ADE-KW. (C) 2017 Elsevier Ltd. All rights reserved.