title: A new apparatus to induce lysis of planktonic microbial cells by shock compression, cavitation and spray.
abstract: Experiments were conducted on an aqueous growth medium containing cultures ofEscherichia coli(E. coli) XL1-Blue, to investigate, in a single experiment, the effect of two types of dynamic mechanical loading on cellular integrity. A bespoke shock tube was used to subject separate portions of a planktonic bacterial culture to two different loading sequences: (i) shock compression followed by cavitation, and (ii) shock compression followed by spray. The apparatus allows the generation of an adjustable loading shock wave of magnitude up to 300 MPa in a sterile laboratory environment. Cultures ofE. coliwere tested with this apparatus and the spread-plate technique was used to measure the survivability after mechanical loading. The loading sequence (ii) gave higher mortality than (i), suggesting that the bacteria are more vulnerable to shear deformation and cavitation than to hydrostatic compression. We present the results of preliminary experiments and suggestions for further experimental work; we discuss the potential applications of this technique to sterilize large volumes of fluid samples.
authors.affiliation: Department of Mechanical Engineering , Khalifa University , Abu Dhabi , UAE.
authors.forename: A
authors.initials: A
authors.lastname: Schiffer
authors.affiliation: Department of Earth Sciences , University of Oxford , South Parks Road , Oxford OX1 3AN , UK.
authors.forename: M N
authors.initials: MN
authors.lastname: Gardner
authors.affiliation: Department of Engineering Science , University of Oxford , Parks Road, Oxford OX1 3PJ , UK.
authors.forename: R H
authors.initials: RH
authors.lastname: Lynn
authors.affiliation: Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK; Department of Aeronautics, Imperial College London, London SW7 2AZ, UK.
authors.forename: V L
authors.identifier: 0000-0002-6696-676X
authors.initials: VL
authors.lastname: Tagarielli
keywords: Escherichia coli; cavitation; cell lysis; shock wave