Experimental study of microorganism disruption using shear stress

Yusaf, Talal (2013) Experimental study of microorganism disruption using shear stress. Biochemical Engineering Journal, 79. pp. 7-14. ISSN 1369-703X


There has been a broad spectrum of theoretical and experimental works on microorganism disruption methods undertaken in the past. However, there is a lack of understanding regarding the actual reasons for microorganism disruption using ultrasound and whether it is caused by shock or shear. In the case of shear stress, which is the focus of this paper, analysis of the intense turbulent flow region of an in-house built shear apparatus combined with the experimental results demonstrated that when the energy dissipation rate in the turbulence region is high, and the size of the eddy is smaller than the size of the cell, the likelihood of yeast disruption is high. The mechanical properties of yeast cells combined with the calculated energy dissipation rate were used to evaluate the yeast disruption efficiency (log reduction). The results show that the shear apparatus can efficiently and effectively disrupt S. cerevisiae at different treatment times, suspension temperatures and rotor speeds. The experimental work suggests that maximum yeast log reduction was achieved when the maximum power dissipation of 2.095 kW was recorded at 10,000 RPM, while suspension temperature was controlled below 35 °C. The corresponding shear stress at 10,000 RPM was 2586.2 Pa.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2013 Elsevier B.V. Published version deposited in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering
Date Deposited: 24 Jul 2013 06:49
Last Modified: 14 Jul 2014 06:29
Uncontrolled Keywords: yeast; shear treatment; cell disruption; energy; water
Fields of Research : 09 Engineering > 0913 Mechanical Engineering > 091305 Energy Generation, Conversion and Storage Engineering
09 Engineering > 0915 Interdisciplinary Engineering > 091508 Turbulent Flows
06 Biological Sciences > 0601 Biochemistry and Cell Biology > 060106 Cellular Interactions (incl. Adhesion, Matrix, Cell Wall)
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Identification Number or DOI: 10.1016/j.bej.2013.07.001
URI: http://eprints.usq.edu.au/id/eprint/23782

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