FOOD SCIENCE ›› 2017, Vol. 38 ›› Issue (10): 92-97.doi: 10.7506/spkx1002-6630-201710016

• Bioengineering • Previous Articles     Next Articles

Isolation, Identification and Growth Characteristic Analysis of Pellicle-Forming Bacteria from Spoiled Vegetable

HE Penghui , QIAN Yang , WANG Meng , YANG Jiantao , ZHAO Tingting , JIANG Yunlu , CHE Zhenming , RAO Yu   

  1. 1. College of Food and Bioengineering, Xihua University, Chengdu 610039, China; 2. Sichuan Dongpo Chinese Paocai Industrial Technology Research Institute, Meishan 620020, China; 3. Sichuan Institute for Food and Drug Control, Chengdu 610097, China
  • Online:2017-05-25 Published:2017-05-23

Abstract: The main microbes which could form pellicle in spoiled vegetable were isolated and identified. The growth characteristics of these microbes were also analyzed. Tryptone soy agar (TSA) medium was used to isolate the pellicleforming microorganisms. Fifty isolates were selected randomly from TSA medium and inoculated into tryptone soy broth medium supplemented with fermented brine (TFB). Six isolates which could form pellicle on the surface of the medium were subjected to 16S rDNA or 18S rDNA identification. The results showed that the pellicle-forming agents were all bacteria, which were identified as Bacillus subtilis, Citrobacter freundii, Staphylococcus cohnii subsp. cohnii, Providencia vermicola, Klebsiella sp. and Enterobacter cloacae. The pellicle-forming abilities of each isolate in different model media were different. Bacillus subtilis and Staphylococcus cohnii subsp. cohnii could also increase the pH value of the medium and had lower nitrogen requirement. Klebsiella sp. and Providencia vermicola could form pellicle only in TFB and TSA supplemented with squeezed juice from fermented vegetable (TFVJ). The bacteria described above might be the key agents for pellicle formation and pose a potential risk for fermented vegetable quality.

Key words: pellicle, fermented vegetable, model media, 16S rDNA, pH variation

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