FOOD SCIENCE ›› 2013, Vol. 34 ›› Issue (8): 253-258.doi: 10.7506/spkx1002-6630-201308055

Previous Articles     Next Articles

Detection of Lactic Acid Bacteria in Commercial Yoghurt by PCR-DGGE Combined with Species-Specific PCR

WANG Ying,MENG Xiang-chen   

  1. Key Laboratory of Dairy Science, Ministry of Education, College of Food Science and Technology, Northeast Agricultural University, Harbin 150030, China
  • Received:2011-12-29 Revised:2013-03-15 Online:2013-04-25 Published:2013-05-07
  • Contact: [中]孟祥晨 [英]MENG Xiang-Chen E-mail:xchmeng@163.com

Abstract: Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) combined with species-specific PCR was used to detect lactic acid bacteria in commercial yoghurts. DGGE conditions were optimized and the results indicated that the optimal conditions of DGGE were 30%–60% denaturant gradient range and 300 min electrophoresis. Lactobacillus plantarum and Bifidobacterium lactis could be distinguished, while Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus acidophilus, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus rhamnosus could not be distinguished. Furthermore, species-specific PCR was used to distinguish among the strains with the same migration distance in gel. Lactic acid bacteria in six commercial yoghurts were detected by PCR-DGGE combined with species-specific PCR. All yoghurts contained Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus plantarum; three kinds of yoghurts contained Lactobacillus casei; Bifidobacterium lactis stated on the label was not detected in one kind of yoghurt. Lactic acid bacteria in yoghurt were isolated and enumeratied by selective medium and the results were confirmed by previously approved technology. Therefore, PCR-DGGE coupled with speciesspecific PCR was an effective method to detect lactic acid bacteria in yoghurt.

Key words: denaturing gradient gel electrophoresis, species-specific PCR amplification, lactic acid bacteria, yoghurt

CLC Number: