| Forty-five strains of bacteria have been isolated from concentrated apple juice processing. All of them can grow at K agar (pH 4.0), but can't grow at LB palate (pH 7.0). The growth pH range and optium pH of strain 2-1, strain S-13-2, strain S-32, and strain S-32-4 were researched. It was proved that the growth pH range of strain 2-1, strain S-13-2, strain S-32, and strain S-32-4 were2.5~5.0, 2.5~6.5, 3.0~6.5, 2.5~5.5 respectively, and the optium pH of strain 2-1, strain S-13-2, strain S-32, and strain S-32-4 were 3.0~3.7, 3.7~5.0, 3.0~4.5, and 3.0~4.5 respectively. This indicated that all the tested strains were as acidophilic as bacteria of Alicyclobacillus genus.The growth temparture range and optium growth temparture of strain 2-1, strain S-13-2, strain S-32, strain S-32-4, and strain 24-1 were researched in this study. The growth temparture range of strain 2-1, strain S-13-2, and strain 24-1 were all from 25℃ to 55℃; of strain S-32 and strain S-32-4 were from 40 ℃ to 60℃ and 30℃ to 70℃ respectively. The optium growth temparture of strain 2-1, strain S-13-2, strain S-32, strain S-32-4, and strain 24-1 were all from 45℃ to 55℃. It indicated that all the tested strains were as thermophilic as bacteria of Alicyclobacillus genus.According to the above research, all the strains isolated from concentrated apple juice processing were acido-thermophilic bacteria. But in Chinese literature, there were several kinds of names of these bacteria. That can make much confusion during the literature research, especially to the researchers who come into this field firstly. So, we suggested a uniform Chinese name "Shi Re Shi Suan Jun" to this kind of bacteria.By using heat resistance test, 38 strains of these bacteria could be classified into 3 groups according to their spore-forming cultivating time. 32 strains of them had the same spore-forming cultivating time as Alicyclobacillus acidoterrstris DSM 3922T, which could produce spores within 48 h when cultivated at 45℃, they were 72% of all tested strains; 3 strains of them could grow very fast and produced spores within 17 h, they were 14% of all tested strains; and 3 strains of them produced spores 48 h later, they were 14% of all tested strains.According to bacteria identification methods and related literature, we used 51 kinds of fermenting substratum, 7 unidentified strains and 5 reference strains of Alicyclobacillus genus {A.acidoterrstris DSM 3922T, A. cycloheptanicus DSM 4006T, A. acidocaldarius DSM 446T, A. hepsperidum DSM 12489T, and A. acidiphilus DSM 14558T ) to study their phenotypic characteristics and analysis the results by the unweighted pair group method with arithmetic mean (UPGMA).The result indicated that all the similarity level of any two strains were less than 80% . It indicated that all of the 12 tested strains belonged to deferent species. That was to say, all the unidentified strains were different species from the reference strains. There may be new species or gunes. Further research should be carried on to identify them.In addition, 29 unidentified strains and 5 referrence strains were classified by PCR-RFLP. Theresults indicated that the strains of 1-4 and 1-2-4 were the same species as reference of strain A. acidoterrstris DSM 3922T and the strains of 4-2-1, S-22 and 5-1 were the same species as reference of strain A. cycloheptanicus DSM 4006T. The other tested strains were different from all the reference strains in this study and most likely to be new species or gunes of thermo-acidophilic, strictly aerobic, spore-forming bacteria.Tests of phenotypic characteristics and 16S r DNA PCR-RFLP got the same result. That among these isolated strains, there were new species or gunes different from the related reference strains of A.acidoterrstris DSM 3922T, A. cycloheptanicus DSM 4006T, A. acidocaldarius DSM 446T, A. hepsperidum DSM 12489T, and A. acidiphilus DSM 14558T, Bacillus subtilis CGMCC 1. 2009T, and Bacillus coagnlans CGMCC 1.943T. It is necessary to study whether these strains could make up new classification unit.In order to study whet...
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