Diferenciación de cepas de Bifidobacterium animalis subespecie lactis con el método AFLP

Abstract

[ES] La identificación de microorganismos probióticos del género Bifidobacterium animalis subespecie lactis es de gran importancia dado su extendido uso como ingrediente alimenticio, ya que confiere beneficios saludables al huésped si se administra en las dosis adecuadas. Las cepas de B. animalis subsp. lactis han demostrado tener mejor viabilidad y supervivencia en productos alimentarios (yogures o productos de leche fermentada) que otras especies de Bifidobacterium. Para proceder a la correcta identificación de las cepas se emplea el método AFLP (Amplified Fragment Length Polymorphism), se trata de una técnica de genotipado que consiste en una digestión completa del ADN, seguida de dos reacciones de PCR y una lectura de los productos obtenidos mediante electroforesis

[EN] The identification of probiotic microorganisms of the group Bifidobacterium animalis subespecie lactis have a lot of importance because of the extended use as food ingredient, since they awards healthy benefits to the host if they are administrated in adecuate doses. The present work has as objective the screening of different techniques that allow to discriminate among the strains of this species made by the company Biopolis. The comparative performed among the genomes of sequenced strains indicate that they are practically identical, with similarities up to 99,4 %, for what it turns out to be very complicated to find significant differences that allow to differentiate them with conventional techniques. The used methods based on sequence of 16S DNA, Real-Time PCR, Random Amplified Polymorphic DNA (RAPD-PCR) and rep-PCR allowed to differ among species of the genus Bifidobacterium, but not among strains of the species B. animalis. Additional, there has been evaluated in silico a procedure based on the technique Amplified Fragment Length Polymorphism (AFLP-PCR) that would be able to discriminate among strains.