Antibiofilm Strategies in the Food Industry - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 357

eliminate Pseudomonas aeruginosa and Pseudomonas stutzeri biofilms from sur-
faces. The disadvantage of this method is that hot water denatures proteins and
increases the adhesion properties of equipment, which can aid in the formation of
biofilms, so it is not advisable. In order to be more efficient in biofilm removal, this
method should be combined with chemical disinfection.
Ultrasounds, the application of electrical fields and super-high magnetic fields
have been identified as newer physical methods for biofilm control. These
approaches will be addressed below.
5 Emergent Approaches
5.1 Ultrasons
Ultrasonication has been reported as an efficient biofilm removal method. This
technique is particularly useful in surface decontamination where the inrush of fluid
that accompanies cavitational collapse near a surface is nonsymmetric (Chemat
et al. 2011 ). The particular advantage of ultrasonic cleaning in this context is that it
can reach crevices that are not easily reached by conventional cleaning methods.
The use of ultrasound allows the destruction of a variety of fungi, bacteria, and
viruses in a much reduced processing time when compared to thermal treatment at
similar temperatures (Chemat et al. 2011 ). However, by itself, this technique
doesn't eliminate all the bacteria in food industries and thus it is recommended to
be used in combination with other treatment techniques (Srey et al. 2013 ). In fact, it
has been postulated that ultrasound induces cavitation within the biofilm, which
increases transport of solutes, as antimicrobial agents, through the biofilm or outer
bacterial membranes (Carmen et al. 2005 ). Thus, there is a synergistic effect
between ultrasound and other antimicrobial agents. For instance, the combination
of ultrasound and ethylenediaminetetraacetic acid (EDTA), and ultrasound and
enzymes showed a higher efficacy in removing biofilms. Baumann and coworkers
( 2009 ) also showed a significant effect on biofilm removal on stainless steel food
contact surfaces by combining the use of ozonation and sonication.
5.2 Electrical Methods
Electrical methods for controlling bacterial adhesion have received special atten-
tion and are regarded to be environmental friendly because they use “electrons” as
the nontoxic reaction mediator. These methods can be divided into current and
potential applications, and each application can be conducted in the cathodic,
anodic, and block (or alternating) modes (Hong et al. 2008 ). Electrical methods
have been applied in some studies to prevent bacterial adhesion and to detach