ALICYCLOBACILLUS DETECTION AGAR
CAT Nº: 2002
For the detection of Alicyclobacillus in fruit juices
FORMULA IN g/l
D (+) Glucose
5.00
Calcium Chloride
0.0006
Potassium Dihydrogenphosphate
3.00
Sodium Molibdate
0.00030
Yeast Extract
2.00
Zinc Sulfate
0.00018
Magnesium Sulfate
0.50
Manganase Sulfate
0.00015
Calcium Chloride
0.25
Boric Acid
0.00010
Ammonium Sulfate
0.20
Bacteriological Agar
18.00
Final pH 4.0 ± 0.2 at 25ºC
Aliclyclobacillus acidoterrestris
ATCC 27009
PREPARATION
Suspend 29 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation.
Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at 121°C
for 15 minutes. The prepared medium should be stored at 8-15°C. The color of the prepared medium is amber.
Note. - The medium is manufactured with a pH of 5.3 ± 0.2 in order to mantain the gel strenght during sterilization.
Adjust thepH at 4.0 ± 0.2 after autoclaving, adding 1.7 ml per liter of medium of 1 N H 2SO4. Homogenize gently and
pour intro petri plates.
The dehydrated medium should be homogeneous, free-flowing and beige in color. If there are any physical changes,
discard the medium.
USES
ALICYCLOBACILLUS DETECTION AGAR is a medium for the detection of Aliclyciclobacillus in fruit juices.
Spoilage of shelf stable fruit juice products by Alicyclobacillus bacteria can be very costly to the fruit juice industry. The
spores, often present in fruit concentrates, are heat resistant and can survive heat processes used by juice
manufacturers. It is therefore important that concentrates and other raw materials are screened for spores of these taint
producers to reduce the risk of spoilage of processed products. Alicyclobacillus is a thermophilic acidophilic sporeforming bacteria which can grow at low pH and at moderately high temperatures such as 40°C microorganism. As
Alicyclobacillus survive the traditional thermal treatments used in the food industry, its presence in packaged products
can cause flavour alterations. They do not produce gas or cause any change in the appearance of the beverage
container, and therefore the spoilage is discovered only when the consumer opens and begins to consume the product.
Fortunately, Alicyclobacillus are not pathogenic bacteria,
Dextrose is the fermentable carbohydrate providing carbon and energy. Potassium Dihydrogenphosphate act as a buffer
system. Yeast extract is source of vitamins, particularly the B-group. The medium is especially characterized by the
presence of many trace elements. Bacteriologial agar is the solidifying agent. The pH value and the high incubation
temperature inhibit the contaminating flora.
Incubate the medium for 3-5 days at 45 ± 1 ºC. Confirm the suspicious colonies by further testing.
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www.condalab.com
MICROBIOLOGICAL TEST
The following results were obtained from type cultures in the performance of the medium after incubation at a
temperature of 45 ± 1.0 C, under anaerobic conditions, and observed after 3-5 days hours.
Microorganisms
Growth
Alicyclobacillus acidocaldarius ATCC 27009
Good
Alicyclobacillus acidoterrestris ATCC 49025
Good
Escherichia coli ATCC 25922
Inhibited
BIBLIOGRAPHY
BAUMGART, J. and MENJE, S.: The Impact of Alicyclobacillus acidoterrestris on the Quality of Juices and Soft Drinks. Fruit Processing
7; 251- 254 (2000)
IFU Working Group Microbiology: First Standard IFU-Method on the Detection of Alicyclobacillus in Fruit Juices. (April 2003)
Jensen Nancy, Evaluation of detection methods for alicyclobacilli in fuit juice concentrates in Australia. Food Science, Australia
Akira Yokota, Tateo Fujii, Keiichi Goto, Alicyclobacillus: Thermophilic Acidophilic Bacilli. Springer (2008)
STORAGE
25ºC
Once opened keep powdered medium closed to avoid hydration.
2ºC
2
LABORATORIOS CONDA, S.A.
www.condalab.com