Molecular identification and typing of lactobacilli isolated from kefir grains

DELFEDERICO, LUCRECIA; HOLLMANN, AXEL; MARTINEZ, MARIANO; IGLESIAS, GABRIEL; DE ANTONI, GRACIELA; SEMORILE, LILIANA

Journal of Dairy Research

CAMBRIDGE UNIV PRESS

Año: 2005 vol. 73 p. 20 - 27

0022-0299

Seventeen heterofermentative lactobacilli isolated from kefir grains were characterized bymolecular methods. Bacterial isolates were identified by amplification of 16S rRNA gene andanalysis by Amplified Ribosomal DNA Restriction Analysis (ARDRA), using the restrictionenzymes Hae III, Dde I, and Hinf I. ARDRA analysis of lactobacilli isolates showed, for eachenzyme used, a same banding pattern between the heterofermentative lactobacilli and thereference strains Lactobacillus kefir JCM 5818 and Lb. kefir ATCC 8007. Other referencelactobacilli and one homofermentative isolate showed differences in at least one of thesepatterns. 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 thatsequencing of this genome region is a good tool for a reliable identification of members ofLb. kefir species. Genotyping of isolates was performed by Random Amplified PolymorphicDNA (RAPD-PCR) analysis using M13, Coc, ERIC-2 and 1254 primers. Patterns obtainedallowed the differentiation of isolates in three groups. The three clusters showed by RAPD-PCRanalysis could be correlated with at least three different strains of Lb. kefir species in the groupof heterofermentative lactobacilli isolates obtained from Argentinian kefir grains.