Agriculture Reference
In-Depth Information
L. monocytogenes
, and
Salmonella spp
) on a variety of FFVs without degrading
product quality (Kim and others 2008; Mahmoud and Linton 2008; Park and others
2008 ; G ó mez - L ó pez and others 2007; Mahmoud and others 2007 ). Tough - to - kill
bacterial spores are especially resistant, and a number of spore-forming bacteria of
Bacillus
and
Clostridium
species inhabit soils, are commonly found on fresh produce,
and have the potential to cause food spoilage and foodborne disease (Setlow and
Johnson 2007 ). There is signifi cant interest in devising methods for overcoming spore
resistance to chemical agents, not only for disinfecting fresh produce, but also for
sanitizing food-processing or -handling equipment, including removing biofi lms, and
for decontaminating biothreats (e.g.,
Bacillus anthracis
). We focus our attention here
on understanding the nature of the interactions of chlorine dioxide (and other chemical
sanitizing agents) with bacterial spores and vegetative pathogens in the context of
enhancing fresh produce safety using the PCS, D-FENS, and MAP technologies, all
of which have potential dual-use applicability to benefi t military and civilian
consumers.
Bacterial Spore Resistance to and Inactivation by Chemical Agents
Bacillus
and
Clostridium
species can form bacterial spores, one of the most resistant
of all life forms. Although such spores can remain metabolically dormant for long
periods of time in environments with signifi cant nutrients or appropriate stimuli
present, spores can rapidly germinate and return to active growth. Spore resistance to
and inactivation by particular chemical agents such as chlorine dioxide is due to a
variety of factors and is best understood in terms of the novel structure of the spore
(Fig. 14.1), which is very different from that of a growing cell, because a number of
Figure 14.1.
Schematic representation of the structure of a dormant
Bacillus
spore.
The various layers are not drawn to scale, and the exosporium is not present, or at most
vestigial, in spores of many species.
