FOOD SCIENCE ›› 2017, Vol. 38 ›› Issue (8): 74-79.doi: 10.7506/spkx1002-6630-201708013

• Bioengineering • Previous Articles     Next Articles

Separation and Diversity of Lactic Acid Bacteria Possessing Antimicrobial Activity Isolated from the Intestine of Marine Animals in South China Sea

JIAO Dongdong, REN Wenbin, ZHAO Yamei, HOU Xiaoqin, LIU Ying, SUN Lijun, WANG Yaling   

  1. 1. Key Laboratory of Aquatic Product Processing and Safety of Guangdong, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China; 2. College of Food Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510230, China; 3. Huzhou Environmental Science and Technology Innovation Center, Huzhou 313000, China
  • Online:2017-04-25 Published:2017-04-24

Abstract: Lactic acid bacteria (LAB) were isolated from the intestine of 10 common kinds of marine animals collected from the South China Sea by the pour plate method. The antimicrobial activity of the LAB isolates was determined by Oxford cup diffusion method against five pathogenic indicator strains including E. coli, V. parahaemolytics, S. aureus, B. subtilis, and L. monocytogenes. The diversity analysis of these LAB strains was conducted by establishing phylogenetic tree based on 16S rRNA gene sequences. The results showed that 43 isolates, which presented soluble calcium circle and were positive by Gram staining and negative in catalase reaction, were identified as LAB according to morphological observation and partial physiological and biochemical experiments, and they all possessed antimicrobial activity in different degrees. Out of these, 13 strains were found to have stronger bacteriostatic ability and a wider antimicrobial spectrum, and they were further identified based on phyogenetical analysis of 16S rRNA sequence. The results indicated that they belonged to 6 genera in 4 families of Firmicutes. Although strain LY-87 and the type strain of Lactococcus lactis subsp. lactis shared 100% 16S rRNA gene sequence similarity, there were genetic differences between other LAB strains and the typical strains showing the closest phylogenetic relationship with them (similarity ranging from 95.7% to 99.9%). The similarity between strain PQ- 26 and the type strain of Pediococcus pentosaceus was only 95.7% suggesting that it is likely to be a potential new species of Pediococcus. This research indicates that LAB with antimicrobial activity are diverse and there may exist potential new species in the intestine of animals from the South China Sea in Zhanjiang. The antimicrobial substances produced by these bacteria need to be further studied and developed.

Key words: marine animal intestine, antimicrobial activity, lactic acid bacteria, 16S rRNA gene, diversity

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