Va-YSG Medium - Cosmo Bio Co.,Ltd.



Va-YSG Medium

Catalog No.: KYO-08901
Size: 100PC
[2 mL x 100 tubes]
Price: ¥20000
catalog info: Catalog 2012-p156
Storage: 4C
Purpose: Detection of guaiacole
component: Va-YSG Medium (2 mL ) 100 tubes
Vanillic acid added YSG medium for guaiacol formation 2 ml x 100 tubes
[Weight] 800g
[Size] 19.5 x 19.5 x 11cm


Alicyclobacillus acidoterrestris is a gram-positive, spore-forming bacillus that occurs widely in nature. This specie has been studied substantially after the incident of turbidity of transparent apple juice in 1984. The Alicyclobacillus genus bacteria, which peculiarly grows under relatively high temperatures and acid conditions, is called Thermo-acidophilic Bacilli (TAB) [1, 2, 3].
TAB are not destroyed by pasteurization and may remain in final products of fabricated food andbeverages. TAB are not known to be harmful to health but are known to degrade the quality of juices and other products by producing guaiacol, causing off-flavor. Even without the off-flavor problem, product values may be degraded by slight deterioration during distribution.
It is very difficult to avoid contamination of TAB, which are common in soil. Fortunately, A. acidocaldarius and other main species that cause contamination are known to be harmless, and damage caused by TAB can be minimizedbymonitoring the contamination of A. acidoterrestris, which is known to be harmful. These species, however, cannot be detected by usual isolation culture methods as they grow only under acidic and relatively high temperature conditions.
Because offrequent occurrence of fruit juice deterioration incidents in Europe and other regions, Japan Fruit Juice Association developed and publicized a unified test method for TAB in March 2003 [4]. To allow easy performance of this test, we developed akit that differentiates A. acidoterrestris in terms of productivity of guaiacol, which causes off-flavor.
1. Take with single inoculation loop, 10 ul , of young colony that has been isolated on YSG agar plate and that has not formed spores. Suspend the colony in a tube of ''Va-YSG medium (2 ml ), '' (1 x 108 cfu/ ml ).
2. Incubate at 45 } 1C for 3 hours.
3. Add 1.0 ml of Reagent 1 of ''Guaiacol Detection Kit''.
4. Add 20 ul of Reagent 2 of ''Guaiacol Detection Kit.
5.Add 20ul of Reagent 3 of ''Guaiacol Detection Kit.
6. Mix well.
7. Let it stand for 5 - 10 minutes.
8. Check the color change of the solution.
*Read the result within 10 minutes
*Blank (Negative Control) Use ''Va-YSG medium (2 ml )'' that has not been inoculated and follow steps 2 - 8.
*Positive Control
Mix well 2 ml of purified water and 100 ul of Positive Control. Follow steps 2 - 8.



•  Niwa,M., A.Kawamoto, Development of a rapid detection method of A. acidoterretris, hazardous bacteria to acidic beverage, Fruit Processing, 13, 102-107 (2003)
•  Niwa,M. (A course for ''Taxonomy and identification of microorganisms'' 1, Taxonomyandquality of new thermostable acidphile bacteria.) Technical data of soft drinks 2001, (1) 9-26 (2001)
•  Niwa,M. (Development of a rapid detection of A. acidoterretris, hazardous bacteria to acidic beverage ) Report of Association for FruitJuice (531) 23-30
•  Niwa, M. A. Kuriyama, A. acidoterretris RAPID DETECTION KIT, Fruit Processing, 13, 328-331 (2003)
•  Niwa, M., Report of Association for Fruit Juice (541) (Sep. 2003), (Proposal for direct detection of of A. acidoterretris using peroxidase method).
◊  Keiichi Goto, Kaoru Mochida, Yuko Kato, Mika Asahara, Rieko Fujita, Sun-Young An, Hiroaki Kasai, and Akira Yokota Int J Syst Evol Microbiol, Jun 2007; 57: 1276 - 1285.