|
Two
different culture mediums were used :
The medium
PCA and the Nutritive Gélose/Agar-Agar medium .
The precise composition
of these mediums can be communicated to you on request.
Seeded
strains and charges with the bacterial carpets :
Two nonpathogenic
stocks: Escherichia Coli (E Coli N°CIP 76.24 - batch 561)
and Listeria innocua (N°CIP 80.11t - batch 763).
Spread out solution
(0,1 ml of mother solution ):
E Coli 4,8 105 UFC/surface
of the gélose/Agar-Agar
Listeria innocua 106
to 107 UFC/surface of Gélose/Agar-Agar
Tested products (including two marketable formulas of AFS-LMC)
:
| A
physiological water witness ....................................................pH
6,32 |
| A
physiological water witness + HCl ..........................................pH
2 to 2,5 |
| AFS-lmc
reference 00J25 / FFO ...............................................pH
2,24 |
| AFS-lmc
reference 00J26 / FFN ...............................................pH
2,13 |
| Sodium
Lactate xxxxx to 60% reference 00L5 ...........................pH
8,13 |
| Potassium
Lactate xxxx to 60% reference 00L4 .........................pH
6,94 |
| Acetate
of sodium xxxxx in solution in Osmosis water to 0,3% ....pH
7,39 |
Tests
carried out :
1) Follow
up of the inhibition of the seeded strains according to different
products products :
The various
products to be tested are absorbed by a cellulose buffer of standardized
gauge, then affixed on the surface of the sown and dried géloses/agar-Agar
(E.Coli or Listeria innocua). These " géloses "
are incubated at 30°C during several days. The follow-up of
the diameters of inhibition is carried out to 24 - 48 - 72 and
168 hours. These figures are transcribed as the surfaces of inhibition
which are removed from the surface of the buffer.
Curves " inhibition surfaces in cm² = f(hours )
" are plotted.
2) Influence
of the dilution of the AFS-LMC :
The protocol
is the same as the one described above, but only for the following
dilutions of products AFS-LMC: Pure product - 1/5 - 1/10 - 1/50
and 1/100.
Controls & Analysis :
They
only relate to the daily measurement of the diameters of inhibition.
|
