Bacteriostatic effect of sequential hydrodynamic and ultrasound-induced stress.
OBJECTIVE
To elucidate the mechanism of action of a nonchemical microbial control technology employing coupled hydrodynamic and ultrasound-induced stress.


RESULTS
The effects of a laboratory model system using a commercial nonchemical device on Pseudomonas putida revealed growth and respiration were inhibited without a loss of viability from the treated population. Damage to cell membranes was evident using fluorescent microscopy and a reporter strain containing lux genes fused with a membrane damage stress-response promoter. Other reporter strains also indicated the possible involvement of DNA and protein repair systems. A consequence of treatment was a reduced ability to form biofilms.


CONCLUSIONS
The nonchemical device caused a biostatic effect on treated cells induced by sublethal damage to several cellular systems, including cell membranes.


CONCLUSIONS
The study demonstrates that biostasis can be an effective mechanism for microbial control in some industrial systems and provides insight into understanding and applying this device and other nonchemical microbial control technologies to real-world problems of microbial contamination.
Ashland Water Technologies, Inc, Wilmington, DE 19808, USA. jchapman@ashland.com
J S
JS
Chapman
R
R
Ferguson
C
C
Consalo
T
T
Bliss
D018441:Biofilms / Q000254:growth & development; D002462:Cell Membrane / Q000473:pathology*; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects / Q000648:ultrastructure; D017930:Genes, Reporter; D057446:Hydrodynamics; D011401:Promoter Regions, Genetic; D016958:Pseudomonas putida / Q000235:genetics / Q000254:growth & development* / Q000528:radiation effects / Q000648:ultrastructure; D013016:Sound; D013312:Stress, Physiological; D014465:Ultrasonics