title: Evaluation of microalgae cell disruption by ultrasonic treatment.
abstract: Microalgae are a promising feedstock for biofuels because of their capability to produce lipids. Cell disruption is necessary to maximize lipid extraction. Sonication conditions were evaluated for breaking heterotrophic (Schizochytrium limacinum) and autotrophic (Chlamydomonas reinhardtii) microalgae cells. Cell disruption was estimated by Nile red-lipids fluorescence quantification in S. limacinum and by the release of intracellular chlorophyll and carotenoids in green microalga C. reinhardtii. In both species, approximately 800 J/10 mL was the energy input necessary to maximize cell disruption, regardless of the cell concentrations studied. Increasing sonication time produced increasing amount of free radicals, quantified by the formation of hydroxyterephthalate. Sonication energy beyond the level needed for cell disruption induced oxidation of arachidonic acid, a polyunsaturated fatty acid typically found in marine lipids. Careful control of sonication conditions is necessary to maximize oil extraction at the lowest operational cost and to prevent oil from free radical-induced degradation.
authors.affiliation: Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011-1061, USA.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Gerde
authors.forename: Melissa
authors.initials: M
authors.lastname: Montalbo-Lomboy
authors.forename: Linxing
authors.initials: L
authors.lastname: Yao
authors.forename: David
authors.initials: D
authors.lastname: Grewell
authors.forename: Tong
authors.initials: T
authors.lastname: Wang
mesh_terms: D002458:Cell Fractionation / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D008055:Lipids / Q000302:isolation & purification*; D058086:Microalgae / Q000502:physiology* / Q000528:radiation effects*; D011829:Radiation Dosage; D013010:Sonication / Q000379:methods*
chemical_list: D008055:Lipids