title: Nutrient recycling of lipid-extracted waste in the production of an oleaginous thraustochytrid.
abstract: Improving the economics of microalgae production for the recovery of microbial oil requires a comprehensive exploration of the measures needed to improve productivity as well as to reduce the overall processing costs. One avenue for cost reduction involves recycling the effluent waste water remaining after lipid extraction. This study investigates the feasibility of recycling those wastes for growing thraustochytrid biomass, a heterotrophic microalgae, where wastes were generated from the enzymatic extraction of the lipids from the cell biomass. It was demonstrated that secondary cultures of the tested thraustochytrid grown in the recycled wastes performed favorably in terms of cell and oil production (20.48 g cells L(-1) and 40.9 % (w/w) lipid) compared to the control (13.63 g cells L(-1) and 56.8 % (w/w) lipid). Further, the significant uptake of solubilized cell material (in the form of amino acids) demonstrated that the recycled waste has the potential for offsetting the need for fresh medium components. These results indicate that the implementation of a nutrient recycling strategy for industrial microalgae production could be possible, with significant added benefits such as conserving water resources, improving production efficiency, and decreasing material inputs.
authors.affiliation: Department of Process Engineering and Applied Science, Faculty of Engineering, Dalhousie University, Sexton House E102, Halifax, NS, Canada. Joshua.Lowrey@Dal.ca.
authors.forename: Joshua
authors.initials: J
authors.lastname: Lowrey
authors.affiliation: Department of Process Engineering and Applied Science, Faculty of Engineering, Dalhousie University, Sexton House E102, Halifax, NS, Canada.
authors.forename: Marianne S
authors.initials: MS
authors.lastname: Brooks
authors.affiliation: Department of Process Engineering and Applied Science, Faculty of Engineering, Dalhousie University, Sexton House E102, Halifax, NS, Canada.|Mara Renewables Corporation, 101 Research Drive, Dartmouth, NS, B2Y 4T6, Canada.
authors.forename: Roberto E
authors.initials: RE
authors.lastname: Armenta
mesh_terms: D000596:Amino Acids / Q000032:analysis; D064751:Ammonium Compounds / Q000032:analysis; D018533:Biomass; D055598:Chemical Phenomena; D005227:Fatty Acids / Q000032:analysis; D005285:Fermentation; D019649:Food Industry; D052836:Heterotrophic Processes; D008055:Lipids / Q000096:biosynthesis / Q000302:isolation & purification*; D058086:Microalgae / Q000378:metabolism*; D010710:Phosphates / Q000032:analysis; D059027:Recycling / Q000379:methods*; D058009:Stramenopiles / Q000378:metabolism*; D018505:Waste Management; D014866:Waste Products; D062065:Wastewater / Q000032:analysis
chemical_list: D000596:Amino Acids; D064751:Ammonium Compounds; D005227:Fatty Acids; D008055:Lipids; D010710:Phosphates; D014866:Waste Products; D062065:Wastewater
keywords: Amino acids; Ectoplasmic net; Enzyme hydrolysate; Heterotrophic microalgae; Media recycling; Nutrient recycling; Secondary fermentation; Spent media