Application of Low Intensity Pulsed Ultrasound for Microbial Cell Stimulation in Bioprocesses And Development of Carbon-based Silver Covered Filters for Microbial Cells Removal in Water Systems

  • Author / Creator
    Savchenko, Oleksandra
  • Renewable resources with their potential application in food industry, pharmacy, energy sector, chemistry, material science etc. can be a major player in our everyday lives. Apart from sustainability in the production, the use of bioprocesses in the energy production and waste water treatment can address the important problem of water, soil and air pollution as well as climate change, which can be essential for a higher level of life quality on the planet. Therefore, the potential use and modification of microorganisms, such as microalgae, in fermentation and as biocatalysts as well as new chemical, physical and biological methods to improve cost-efficiency of green and white biotechnology are gaining a lot of attention from modern research all over the world. One of the alternative approaches to apply in biotechnological production that can successfully improve cost-efficiency and increase yield can be ultrasound - a form of acoustic energy, characterized by frequencies of 20 kHz -1 GHz, or the range that is above the human hearing and lower than the hypersonic regime. Low-intensity pulsed ultrasound (1.5MHz, 20% duty cycle, and intensity between 20mW/cm2 and 200mw/cm2) has been previously used in the bioprocesses and has been proven to increase stem cell, microorganism and antibody growth. This research presents a study on the impact of Low Intensity Pulsed Ultrasound (LIPUS) as a physical method for microorganism growth and activity stimulation, which can be used in combination with all other biological and chemical methods in bioprocesses. The study showed it can be applied in algal biofuel production giving up to 20% increase in lipid yield, in bio-ethanol production using microorganisms with up to 20-30% improvement in sugars to ethanol conversion efficiency, for increasing biomass of microalgae up to 20% with potential use for food, material and pharmaceutical applications, as well as for waste-water treatment with microorganisms. Improving the efficiency of these processes by this mechanism on an industrial scale could yield more affordable price for biofuel or other products of above mentioned bioprocesses. The study has also revealed that LIPUS showed consistent results in different bioprocesses with different microorganisms and duration of cell culture, which indicates that there is a broad spectrum of potential LIPUS applications.

  • Subjects / Keywords
  • Graduation date
    Spring 2017
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
  • Supervisor / co-supervisor and their department(s)
  • Examining committee members and their departments
    • Li, Huazhou (Civil and Environmental Engineering)
    • Burrell, Robert (Biomedical Engineering)
    • Chang, Scott (Renewable Resources)
    • Ma, Kesen (external, University of Waterloo)
    • Chen, Jie (Electrical and Computer Engineering, Biomedical Engineering)
    • Liu, Yang (Civil and Environmental Engineering)