Rapid identification of four lactic acid bacteria using specific PCR in microbial fertilizers

Abstract:

[Objective] Lactobacillus plantarum, L. rhamnosus, L. acidophilus and L. delbrueckii, which were widely used in microbial fertilizers, were indistinguishable from each other just by phenotypic characteristics. Rapid identification of the lactic acid bacteria by specific PCR was necessary for detection and ecological evaluation of microbial fertilizers. [Methods] In this study, based on recA and gyrB genes, four pairs of species-specific primers were designed, and the corresponding specific PCR methods were established. [Results] Forty reference strains belonging to seven genera, such as Lactobacillus, Lactococcus, Pediococcu, Bacillus, Paenibacillus, Brevibacillus and Pseudomonas, were tested. The results showed that, the target single band was consistently amplified from only the 4 strains of lactic acid bacteria. Meanwhile, sixteen strains of lactic acid bacteria from microbial fertilizer products were identified by this specific PCR, the results were consistent with that of 16S rDNA sequence analysis and Biolog. [Conclusion] The methods of specific PCR were species-specific and effective, and could be used in the rapid identification of L. plantarum, L. rhamnosus, L. acidophilus and L. delbrueckii. The results will provide technical supports for the detection and ecological evaluation of microbial fertilizer.