Abstract:

Objective: To evaluate the efficacy of three media, K agar, yeast extract starch glucose (YSG) medium and Bacillus
acidoterrestris (BAT) agar medium each from three manufacturers (Guangdong huankai, manufacturer II and manufacturer
I), in detecting Alicyclobacillus. Methods: The colony growth of standard strains and the separation of Alicyclobacillus
isolates from real samples were evaluated using the three media. Results: The number of colonies of Alicyclobacillus
acidoterrestris reference culture and Alicyclobacillus isolate 4-2 in K medium, YSG medium and BAT medium did not
significantly differ (P > 0.05). Similarly, there was no significant difference in the number of colonies of A. acidoterrestris
reference culture and Alicyclobacillus isolate 5-3 in YSG medium and BAT medium (P > 0.05), but neither could grow in
K medium. The separation and consistency rates of three media from three manufacturers for isolating A. acidoterrestris
in samples were similar. The separation and consistency rates of YSG medium for isolating A. acidocaldarius in samples
were similar to those of BAT medium from HK and manufacturer II, which were better than those from manufacturer I.
Conclusion: K medium was more effective for isolating A. acidoterrestris, but it was not suitable for isolating all
Alicyclobacillus isolates. YSG medium and BAT medium were suitable for isolating all Alicyclobacillus isolates. The media
from HK and manufacturer II had superior performance than those from manufacturer I.

Key words: Alicyclobacillus, culture media, performance evaluation