浓缩苹果汁生产过程中脂环酸芽孢杆菌的分离及初步鉴定

本文对浓缩苹果汁生产过程中的嗜酸耐热菌进行了分离，得到45株纯的嗜酸耐热芽孢杆菌。根据脂环酸芽孢杆菌(Alicyclobacillus)嗜酸的特点，用LB平板进行筛选，结果表明所有的菌株都嗜酸。用抗热性试验研究了这些菌株产生芽孢的培养时间，结果表明，所有考察的菌株中，33株与DSM3922的生长周期一致，48h内产生芽孢；3株菌生长速度较快，培养17h就能产生芽孢；还有3株菌生长速度较慢，需培养48h后才能产生芽孢。在采用16S rDNA PCR-RFLP法对筛选得到的脂环酸芽孢杆菌进行快速鉴定的基础上，选取7株可能是新种的未知菌株与5株已知的参比菌株的19个表型特征进行了试验研究和聚类分析，结果进一步证实了这7株菌都是与已知参比菌株不同的菌株。

Isolation and Identification Alicyclobacillus from Concentrated Apple Juice processing

The forty-five strains of bacteria have been isolated from concentrated apple juice. All of them can grow at K agar (pH 4.0), but can't grow at LB palate (pH 7.0). By using heat resistance test, 38 strains of these bacteria could be classified into 3 groups according to their spore-forming time. 33 strains of them had the same spore-forming time as DSM 3922, which could produce spores within 48 h when cultivated at 45 degrees C; 3 strains of them could grow very fast and produced spores within 17 h; and 3 strains of them produced spores 48h later. Based on the results of 16S rDNA PCR-RFLP analysis, 7 strains of unknown, probably new species and 5 reference strains were selected for 19 phenotypic characteristics test and the result were analyses by UPGMA. The results of phenotypic characteristics test had good agreement with 16S rDNA PCR-RFLP analyses, that the 7 strains were different from all the 5 reference strains, they are new species of Alicyclobacillus.