title: Disruption of microalgal cells using high-frequency focused ultrasound.
abstract: The objective of this study was to evaluate the effectiveness of high-frequency focused ultrasound (HFFU) in microalgal cell disruption. Two microalgal species including Scenedesmus dimorphus and Nannochloropsis oculata were treated by a 3.2-MHz, 40-W focused ultrasound and a 100-W, low-frequency (20kHz) non-focused ultrasound (LFNFU). The results demonstrated that HFFU was effective in the disruption of microalgal cells, indicated by significantly increased lipid fluorescence density, the decrease of cell sizes, and the increase of chlorophyll a fluorescence density after treatments. Compared with LFNFU, HFFU treatment was more energy efficient. The combination of high and low frequency treatments was found to be even more effective than single frequency treatment at the same processing time, indicating that frequency played a critical role in cell disruption. In both HFFU and LFNFU treatments, the effectiveness of cell disruption was found to be dependent on the cell treated.
authors.affiliation: Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695, United States.
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695, United States. Electronic address: wyuan2@ncsu.edu.
authors.forename: Wenqiao
authors.initials: W
authors.lastname: Yuan
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, United States.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, United States.
authors.forename: Yun
authors.initials: Y
authors.lastname: Jing
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, United States.
authors.forename: Zhuochen
authors.initials: Z
authors.lastname: Wang
mesh_terms: D002458:Cell Fractionation / Q000379:methods*; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D015169:Colony Count, Microbial; D005453:Fluorescence; D008055:Lipids / Q000737:chemistry; D058086:Microalgae / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D010078:Oxazines / Q000378:metabolism; D013194:Staining and Labeling; D014465:Ultrasonics / Q000295:instrumentation / Q000379:methods*
chemical_list: D008055:Lipids; D010078:Oxazines; D002734:Chlorophyll; C044808:nile red; D000077194:Chlorophyll A
keywords: Cell disruption; Lipid extraction; Microalgae; Ultrasound