Different strains and toxin-producing ability of Bacillus group members from spices and herbs and its tenacity to storage
學生姓名:
蘇立銘
指導教授:
蕭心怡
學 號:
00539014
學期:
108下
摘 要:
Spices and herbs are usually added to foods to make it look better or have a better smell. However, there might be a lot of pathogens inside the spices and herbs, including Bacillus cereus, Salmonella spp. and Clostridium perfringens. In this study, we try to find out all the Bacillus species and their toxin producing ability in spices and herbs, furthermore, the tenacity of Bacillus is studied also. In the first article, the author used the PCR, microscopy and MLST method to identify the Bacillus group in spices and herbs. The results showed that from eight spices and herbs (including allspice, cinnamon, nutmeg, paprika, pepper, parsley and oregano), at least five different species are identified, including Bacillus cereus (s.s.), Bacillus thuringiensis, Bacillus toyonensis, Bacillus weihenstephanensis and Bacillus mycoides/Baciilus pseudomycoides. As for the toxin, the toxin has been detected from 57 isolates, all of which have the toxin Nhe, and 1 of them have the emetic enterotoxin, cereulide. There is no toxin detected from 2 isolates of B. pseudomycoides/B. mycoides. From the result, we can know that there are diverse Bacillus group in the spices and herbs, and much of them will produce toxins. As for the results of the tenacity of Bacillus group in eight spices and herbs mentioned before, the storage of 50 weeks will not reduce the level of the bacteria, no matter for the Bacillus cereus or Bacillus thuringiensis. In the results of the strain variability, they found that 4 different kinds of Bacillus group did not show the significant difference, further prove that the reduction level will not be different for different strains. In conclusion, there will be many kinds Bacillus group members in spices and herbs, and the bacteria won’t die during storage.
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