304 / 350
24°C 44 and 62 hours
G. candidum
- LOW
Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev
0.1% Peptone Water
9
7
2
9
9
7.200 3.033
9
9
2
11
9
8.000 3.464
0.1% Peptone water (45°C)
9
8
12
8
6
8.600 2.191 10
9
12 10
9 10.000 1.225
Butterfields Buffer
4
2
10
8
2
5.200 3.633
4
2
10
8
4
5.600 3.286
Letheen Broth
7
5
7
11
7
7.400 2.191 11
7
7
14 10 9.800 2.950
Saline
2
3
3
1
3
2.400 0.894
3
5
2
1
3
2.800 1.483
Peptone Salt Diluent
2
1
3
1
3
2.000 1.000
2
2
3
2
3
2.400 0.548
Water
3
3
6
3
3
3.600 1.342
3
3
6
4
3
3.800 1.304
BPW
6
2
4
8
4
4.800 2.280
7
3
6
9
6
6.200 2.168
29°C 44 and 62 hours
G. candidum
- LOW
Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev
0.1% Peptone Water
5
9
9
10
4
7.400 2.702
5
10 10 10
5
8.000 2.739
0.1% Peptone water (45°C)
8
7
4
6
6
6.200 1.483
8
6
4
6
6
6.000 1.414
Butterfields Buffer
3
2
8
8
8
5.800 3.033
3
2
8
8
8
5.800 3.033
Letheen Broth
8
12 10 13
9 10.400 2.074
9
12 10 13
9 10.600 1.817
Saline
2
5
2
2
1
2.400 1.517
2
5
3
2
1
2.600 1.517
Peptone Salt Diluent
4
4
1
4
3
3.200 1.304
4
5
1
4
3
3.400 1.517
Water
2
3
1
5
4
3.000 1.581
2
4
1
5
4
3.200 1.643
BPW
7
9
9
3
8
7.200 2.490
7
9
9
7
8
8.000 1.000
24°C 44 and 62 hours
G. candidum
- HIGH
Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev
0.1% Peptone Water
29 29 30 16 24 25.600 5.857 36 34 38 19 26 30.600 7.925
0.1% Peptone water (45°C)
26 22 26 34 31 27.800 4.712 31 28 32 37 34 32.400 3.362
Butterfields Buffer
20 28 33 28 24 26.600 4.879 21 29 37 19 27 26.600 7.127
Letheen Broth
28 30 25 29 20 26.400 4.037 34 33 26 26 21 28.000 5.431
Saline
21 14 11 15 14 15.000 3.674 20 15 14 18 16 16.600 2.408
Peptone Salt Diluent
17 22 16 17 16 17.600 2.510 17 24 17 17 17 18.400 3.130
Water
17 16 20 19 18 18.000 1.581 19 17 26 20 21 20.600 3.362
BPW
16 20 16 16 15 16.600 1.949 20 21 21 21 23 21.200 1.095
29°C 44 and 62 hours
G. candidum
- HIGH
Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average Sdev
0.1% Peptone Water
31 28 23 29 33 28.800 3.768 31 28 24 30 33 29.200 3.421
0.1% Peptone water (45°C)
21 24 23 26 25 23.800 1.924 21 24 24 28 25 24.400 2.510
Butterfields Buffer
23 32 21 24 26 25.200 4.207 23 31 21 24 26 25.000 3.808
Letheen Broth
31 30 33 32 29 31.000 1.581 31 29 33 32 30 31.000 1.581
Saline
18 12 18 18 22 17.600 3.578 18 12 18 18 22 17.600 3.578
Peptone Salt Diluent
18
6
13 13 17 13.400 4.722 17
7
13 13 17 13.400 4.099
Water
17 22 20 27 19 21.000 3.808 17 23 21 28 19 21.600 4.219
BPW
26 24 20 21 20 22.200 2.683 26 23 21 21 19 22.000 2.646
44 hours
62 hours
62 hours
44 hours
44 hours
62 hours
44 hours
62 hours
1
2
3
A General Linear Model statistic was used to compare the ruggedness parameters. The p values
4
indicated that there were no significant differences in the results obtained by the Petrifilm RYM Plate
5
method for the detection of the low or high yeast or mold levels when minor modifications to
6
incubation temperature (p=0.975), incubation time (p=0.721), dilution buffers (p=0.289) were made.
7
8
Shelf Life and Lot-to-Lot Consistency
9
3M Petrifilm RYM Plates were made from multiple lots of raw materials and were manufactured at
10
different times. Sixty different samples representing three different lots of manufacture and shelf life
11
were created. One yeast,
Candida troplicalis
(Microbiologics 45062-1 2015-03), and one mold,
12
Geotrichum candidum
(Microbiologics 519-1-7 2014-07), were tested at high and low inoculum levels.
13
8
AOAC Research Institute
Expert Review Panel Use Only
OMAMAN-16D/ PTM Report
ERP Use Only - December 2014