A comparison of ozonation and chlorination for the disinfection of
stainless steel surfaces.
Department of Animal, Dairy and Veterinary
Sciences, Clemson University, SC 29634.
Ozonated water and chlorinated sanitizer were compared
for effectiveness against biofilms of milk spoilage bacteria. Stainless
steel plates were incubated in UHT-pasteurized milk inoculated with pure
cultures of either Pseudomonas fluorescens (ATCC 949) or Alcaligenes
faecalis (ATCC 337). After incubation, the plates were removed and
rinsed in sterile PBS. A control rinsed stainless steel plate was
swabbed and plated on standard plate count agar. A second rinsed
stainless steel plate was covered and treated for 2 min with a
commercial chlorinated sanitizer (dichloro-s-triazinetrione), prepared
according to the manufacturer's recommendations; after treatment, the
plate was rinsed twice in sterile PBS, swabbed, and plated on standard
plate count agar. A third rinsed stainless steel plate from the culture
was placed in ozonated deionized H2O (.5 ppm of ozone) for 10 min,
rinsed twice as described, swabbed, and plated. Both ozonation and
chlorination reduced bacteria populations by > 99% at initial cell
densities in the range of approximately 1.24 x 10(5) to 8.56 x 10(5)
cfu/cm2 for P. fluorescens and 1.53 x 10(4) to 8.56 x 10(5) cfu/cm2 for
A. faecalis in milk films on stainless steel surfaces.
PMID: 8270705 [PubMed - indexed for MEDLINE]