title: Algal Cell Response to Pulsed Waved Stimulation and Its Application to Increase Algal Lipid Production.
abstract: Generating renewable energy while sequestering CO2using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii, were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production.
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Oleksandra
authors.initials: O
authors.lastname: Savchenko
authors.affiliation: Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Jida
authors.initials: J
authors.lastname: Xing
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Quanrong
authors.initials: Q
authors.lastname: Gu
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Shaheen
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Min
authors.initials: M
authors.lastname: Huang
authors.affiliation: Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Burrell
authors.affiliation: Department of Biomedical Engineering, University of Bridgeport, Connecticut, USA.|Department of Mechanical Engineering, University of Bridgeport, Connecticut, USA.
authors.forename: Prabir
authors.initials: P
authors.lastname: Patra
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.|Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D019149:Bioreactors / Q000191:economics / Q000382:microbiology*; D048408:Chlorella vulgaris / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D007218:Industrial Microbiology / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D008055:Lipids / Q000096:biosynthesis*; D013010:Sonication / Q000295:instrumentation / Q000379:methods*
chemical_list: D008055:Lipids