title: Molecular identification and typing of lactobacilli isolated from kefir grains.
abstract: Seventeen heterofermentative lactobacilli isolated from kefir grains were characterized by molecular methods. Bacterial isolates were identified by amplification of 16S rRNA gene and analysis by Amplified Ribosomal DNA Restriction Analysis (ARDRA), using the restriction enzymes Hae III, Dde I, and Hinf I. ARDRA analysis of lactobacilli isolates showed, for each enzyme used, a same banding pattern between the heterofermentative lactobacilli and the reference strains Lactobacillus kefir JCM 5818 and Lb. kefir ATCC 8007. Other reference lactobacilli and one homofermentative isolate showed differences in at least one of these patterns. The 16S-23S rRNA spacer region was also used to discriminate the bacterial isolates at the species level. The data obtained from the analysis of spacer region confirmed that sequencing of this genome region is a good tool for a reliable identification of members of Lb. kefir species. Genotyping of isolates was performed by Random Amplified Polymorphic DNA (RAPD-PCR) analysis using M13, Coc, ERIC-2 and 1254 primers. Patterns obtained allowed the differentiation of isolates in three groups. The three clusters showed by RAPD-PCR analysis could be correlated with at least three different strains of Lb. kefir species in the group of heterofermentative lactobacilli isolates obtained from Argentinian kefir grains.
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina.
authors.forename: Lucrecia
authors.initials: L
authors.lastname: Delfederico
authors.forename: Axel
authors.initials: A
authors.lastname: Hollmann
authors.forename: Mariano
authors.initials: M
authors.lastname: Martínez
authors.forename: N Gabriel
authors.initials: NG
authors.lastname: Iglesias
authors.forename: Graciela
authors.initials: G
authors.lastname: De Antoni
authors.forename: Liliana
authors.initials: L
authors.lastname: Semorile
mesh_terms: D015373:Bacterial Typing Techniques; D001483:Base Sequence; D043302:Cultured Milk Products / Q000382:microbiology*; D017931:DNA Primers; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000032:analysis* / Q000235:genetics; D005838:Genotype; D007778:Lactobacillus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods*; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D004262:DNA Restriction Enzymes