title: Investigation of mixotrophic, heterotrophic, and autotrophic growth of Chlorella vulgaris under agricultural waste medium.
abstract: Growth of Chlorella vulgaris and its lipid production were investigated under autotrophic, heterotrophic, and mixotrophic conditions. Cheap agricultural waste molasses and corn steep liquor from industries were used as carbon and nitrogen sources, respectively. Chlorella vulgaris grew remarkably under this agricultural waste medium, which resulted in a reduction in the final cost of the biodiesel production. Maximum dry weight of 2.62 g L(-1) was obtained in mixotrophic growth with the highest lipid concentration of 0.86 g L(-1). These biomass and lipid concentrations were, respectively, 140% and 170% higher than autotrophic growth and 300% and 1200% higher than heterotrophic growth. In mixotrophic growth, independent or simultaneous occurrence of autotrophic and heterotrophic metabolisms was investigated. The growth of the microalgae was observed to take place first heterotrophically to a minimum substrate concentration with a little fraction in growth under autotrophic metabolism, and then the cells grew more autotrophically. It was found that mixotrophic growth was not a simple combination of heterotrophic and autotrophic growth.
authors: a Department of Chemical Engineering , Amirkabir University of Technology , Tehran , Iran.
authors: M A
authors: MA
authors: Mohammad Mirzaie
authors: a Department of Chemical Engineering , Amirkabir University of Technology , Tehran , Iran.
authors: M
authors: M
authors: Kalbasi
authors: b Biotechnology Group, Department of Chemical Engineering , Tarbiat Modares University , Tehran , Iran.
authors: S M
authors: SM
authors: Mousavi
authors: c Biosystems Engineering Department , Tarbiat Modares University , Tehran , Iran.
authors: B
authors: B
authors: Ghobadian
mesh_terms: D000383:Agriculture; D052818:Autotrophic Processes; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D048408:Chlorella vulgaris / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D003470:Culture Media; D052836:Heterotrophic Processes; D008055:Lipids / Q000737:chemistry; D058086:Microalgae / Q000254:growth & development / Q000378:metabolism; D010860:Pigments, Biological / Q000378:metabolism; D031786:Saccharum / Q000737:chemistry; D014866:Waste Products; D003313:Zea mays / Q000737:chemistry
chemical_list: D003470:Culture Media; D008055:Lipids; D010860:Pigments, Biological; D014866:Waste Products
keywords: Agricultural medium; Chlorella vulgaris; cultivation medium; lipid content; mixotrophic growth; photosynthesis pigment