The Standard Plate Count (SPC) means
the colony count of the mesophilic bacteria growing under aerobic condition on standard
methods agar (Plate Count Agar), and SPC becomes the representative index indicating the degree of the microbial contamination of the food.
What is the purpose of standard plate count?
The standard plate count, sometimes also referred to as the total plate count, is probably the most widely used technique for evaluating microorganisms in foods. The purpose, as its name implies, is
to estimate the number of viable microorganism cells in a given sample of food
.
What does standard plate count measure?
The Standard Plate Counts test evaluates
both total aerobic bacterial and total mold and yeasts
. … This test is appropriate for all nonsterile products and provides a standardized means of determining the density of heterotrophic bacteria or microbial content of the sample.
What does total plate count measure?
Total Plate Count. Total Plate Count. The total plate count is
the enumeration of aerobic, mesophillic organisms that grow in aerobic conditions under moderate temperatures of 20-45°C
. This includes all aerobic bacteria, yeast, molds and fungi that grows in the specific agar.
Why is standard plate count performed on food products?
The standard plate count (SPC), also referred to as the aerobic plate count or the total viable count, is
one of the most common tests applied to indicate the microbiological quality of food.
What is a good standard plate count?
The raw plate count results for standard agar plates should be within
25 to 250 colony forming units (CFU)
or reported as an estimate. The recommended counting range for Aspergillus niger and other filamentous colonies is between 8 and 80 CFU per plate.
Is total plate count the same as aerobic plate count?
The APC term stands for aerobic plate count, but again
is interchangeable with the others
. Other terms used more historically are Standard Plate Count, Mesophilic Count or Total Plate Count these too generally refer to aerobic bacteria able to grow at average temperatures (e.g. 30 to 40°C).
What will be the plate count of good quality water?
Heterotrophic plate count levels in potable water should be
<500 CFU/mL
. These levels may increase on occasion, but counts consistently >500 CFU/mL would indicate a general decrease in water quality. A direct correlation between heterotrophic plate count and biofilm levels has been demonstrated.
What is the range for a countable plate?
The countable plate has
between 30 and 300 colonies
. More than 300 colonies would be difficult to count, and less than 30 colonies is too small a sample size to present an accurate representation of the original sample.
What is the difference between total plate count and total viable count?
The main difference between the two is that total count
determines the count of all cells both dead and alive
while viable count estimate the number of viable or live cells only capable of growing into distinct colonies.
What are the limitations of standard plate count?
among these disadvantages are: (1)
the length of time required for incubation, 48 hours being the shortest
; (2) large amount of glassware and culture medium required, as well as other expensive equipment, and (3) the paucity of details regarding the kinds of organisms present.
What is an acceptable aerobic plate count?
Counts outside the normal
25-250 range
may give erroneous indications of the actual bacterial composition of the sample. Dilution factors may exaggerate low counts (less than 25), and crowded plates (greater than 250) may be difficult to count or may inhibit the growth of some bacteria, resulting in a low count.
How do you calculate total bacterial count?
For example, suppose the plate of the 10^6 dilution yielded a count of 130 colonies. Then, the number of bacteria in 1 ml of the original sample can be calculated as follows:
Bacteria/ml = (130) x (10^6)
= 1.3 × 10^8 or 130,000,000.
What are the disadvantages of plate count assays?
The standard plate count is one of the most common of the microbiological methods used to assess the overall quality of foods. The major drawbacks of this method are that
it is time consuming, labor intensive, and expensive when a large number of samples are to be analyzed
.
Which of the following is an advantage of the standard plate count?
The correct answer: An advantage of the standard plate count is that it
e. Determines the number of viable cells
.
Why are 30 300 plate counts viable?
A plate having 30-300 colonies is chosen because this range is
considered statistically significant
. If there are less than 30 colonies on the plate, small errors in dilution technique or the presence of a few contaminants will have a drastic effect on the final count.
