Abstract
In the present study various combinations of metabolic indicators were
used in viability studies of foodborne spoilage and pathogenic
organisms. Various metabolic stains were tested in pure culture
suspensions of Pseudomonas fragi and Listeria monocytogenes containing only viable cells, both viable and dead cells or only dead cells. In addition, foodborne monospecies biofilms of L. monocytogenes and P. fragi were studied. The biofilms were grown on stainless steel (AISI 304, 2B) surfaces. The results showed that both the LIVE/DEAD Bac
Light Viability Kit (LIVE/DEAD) and the 5-cyano-2,3-ditolyl tetrazolium
chloride (CTC)-4′,6-diamidino-2-phenylindole (DAPI) staining procedures
offer a rapid, easy and reliable method for metabolic investigation of
bacteria in suspension and swabbed biofilm bacteria. Assessment of
replicate samples using luciferin–luciferase-based ATP measurement and
conventional cultivation corroborated the results of swabbed biofilm
bacteria obtained by staining. LIVE/DEAD staining cannot be used for
direct staining of biofilms on surfaces, due to interference between the
stain and polysaccharides of the biofilm matrix and slime. Staining by
CTC-DAPI is suitable for studying viability of cells both in suspension
and in biofilms attached to surfaces. The other staining procedures
tested were not satisfactory or only slightly satisfactory in
distinguishing between viable and dead cells.
| Original language | English |
|---|---|
| Pages (from-to) | 225-233 |
| Journal | LWT - Food Science and Technology |
| Volume | 33 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2000 |
| MoE publication type | A1 Journal article-refereed |