Abstract:
The aim of this study was to assess the potential of bacteria Escherichia coli ATCC
35218, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC
25923 and yeast Pichia membranifaciens ZIM 2417 to adhere to wooden surfaces
such as poplar (Populus sp.), Norway spruce (Picea abies), European beech (Fagus
sylvatica), beech coated with the commercial Belinka oil food contact and disinfectant
P3-oxonia active 150, and investigate their survival on the beech wood surface
under different relative humidities (RH; 65%, 75%, 85%, 98%) and temperatures
(10 °C, 20 °C, 27 °C/37 °C). To extend the research goals, the scanning electron
microscopy (SEM) analysis was also performed. The adhesion was determined by
the number of colony-forming units per mm2
of sample (CFU/mm2). Results showed
that all tested bacteria and yeast were able to adhere to the wooden surfaces, although
differences were observed according to strains and type of wood. It was evident that
number of adhered cells of S. aureus was lower on spruce (3.62 × 103 CFU/mm2)
compared to poplar and beech (1.09 × 105 and 2.11 × 104 CFU/mm2, respectively).
Furthermore, oil and disinfectant promoted the adhesion of P. aeruginosa (155.93
and 130.50%, respectively) on the beech surfaces, while they had a strong inhibitory
effect on the other tested microorganisms E. coli (87.44 and 88.44%, respectively),
S. aureus (91.24 and 96.80%, respectively) and P. membranifaciens (92.45
and 87.24%, respectively). These findings are consistent with SEM micrographs.
The current data also indicated that relative humidity and temperature significantly
affected the adhesion of tested bacteria and yeast. The highest degree of adhesion
was observed at a relative humidity of 98% and temperature of 20 and 37 °C for bacteria,
or 20 and 27 °C for yeast. Thus, the knowledge of how these microorganisms
adhere to wooden surfaces and which factors affect this phenomenon proves to be of
great importance in order to avoid their colonization.
