Microbial strains including Staphylococcus aureus,
Bacillus cereus, Listeria monocytogenes, Salmonella sp.,
Saccharomyces cerevisiae var. sake and Aspergillus fumigatus
TISTR 3180 were obtained from culture collection of
Microbiology Laboratory, Faculty of Agro-Industry, Prince
of Songkhla University. Escherichia coli O157: H7 DMST
12743 was obtained from the Department of Medical Science
(DMSC), Ministry of Health (Bangkok, Thailand). All bacterial
and yeast strains were cultivated in Mueller Hinton Broth
(MHB) and Yeast Malt Broth (YMB), respectively at 37oC
for 18 h. Approximately 1 ml of culture was transferred to 9
ml of broth medium and incubated at 37oC for another 15 h,
cell concentration was then adjusted to obtain final concentration
of 106 CFU/ml using MHB and YMB for bacteria and
yeast, respectively. Fungal spores were prepared by growing
mold on Potato Dextrose Agar (PDA) at 37oC for 7 days, and
spores were suspended in sterile 1% tween-80. Spore count
was performed by using hemacytometer, and adjusted to
obtain 106 spores/ ml with Potato Dextrose Broth (PDB).