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Chapter 6
However, the extent of biofilm formed by the strains was also influenced
by the method and conditions chosen.
Furthermore it was identified that other factors such as biofilm substrata
and duration of biofilm development influence the density of biofilm
formed. Biofilm substrata in particular had a major and consistent impact
on the density of biofilm formed. More cells were consistently recovered
from tile than concrete, glass, steel and polycarbonate. This indicates that
surface roughness alone may not provide a clear indication on the ability of
surfaces to support dense biofilm formation. Moreover, there is limited
work examining S. enterica biofilm formation on tile, on the other hand,
there is a great deal more research reporting biofilm density of glass [56,
84, 106, 134, 189], steel [148, 188, 207, 220] and plastic surfaces [56, 86,
96, 111-112, 159, 165, 178, 191]. The finding that S. enterica formed a
more dense biofilm on tile that any of the other surfaces used in biofilm
suggests the relationship between biofilm substratum and S. enterica
biofilm density may be currently underestimated. This may have important
implications for the food processing and handling industry suggesting that
it may be necessary to consider the appropriateness of having materials
such as tile in the food processing areas. It is also important to highlight
that all materials were able to support biofilm formation using the CBR,
this may also need consideration as many of these products are used in the
food manufacturing industry.
Furthermore, the results also indicated that Salmonella biofilm density
increased over time using the CBR. The research presented in chapter 4
indicated that the biofilm developed over an extended period of time was
more resistant to disinfectant treatment. Previous research has suggested
that Salmonella biofilm density does not increase substantially over time
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