Determination of citrus fruit origin by using 16S rDNA fingerprinting of bacterial communities by PCR- DGGE: an application to clementine from Morocco and Spain.

Introduction. Consumption of citrus fruits and their juice has strongly grown in the last few decades. However, at the present time, the traceability of these fruits is only documentary. In case of doubt or fraud, no standardized analysis makes it possible to discriminate or determine the geographical origin of culture of the fruit. Materials and methods. A method of bacterial ecology, PCR-DGGE, was used to characterize the bacterial flora of clementines imported into France from Spain and Morocco in order to show that there is a relation between the bacterial communities of the fruits and their geographical origins. The principle rests on the determination of specific biological markers for a given region. Protocols of microbial extraction and DNA amplification were optimized. Results. DGGE profiles analyzed by multivariate analysis permitted us to distinguish microbial communities from different origins. Conclusion. We propose the PCR-DGGE method as a new tool for traceability that provides citrus products with a unique bar code and makes it possible to trace back the citrus fruit to their original location.introduction. La consommation des agrumes et de leur jus s''est fortement d?velopp?e pendant ces derni?res d?cennies. Cependant, ? l''heure actuelle, la tra?abilit? de cette fili?re est uniquement documentaire. En cas de doute ou de fraude, aucune analyse normalis?e ne permet de discriminer ou de d?terminer l''origine g?ographique de la culture du fruit. Mat?riel et m?thodes. Une m?thode d''?cologie bact?rienne, la PCR-DGGE, a ?t? utilis?e pour caract?riser la flore bact?rienne des cl?mentines import?es en France d''Espagne et du Maroc afin de montrer qu''il existe une relation entre les communaut?s bact?riennes des fruits et leurs origines g?ographiques. Le principe repose sur la d?termination de marqueurs biologiques sp?cifiques d?une localisation donn?e. Les protocoles d''extraction et d''amplification des ADN microbiens ont ?t? optimis?s. R?sultats. Le profil de DGGE ?tudi? par une analyse multivari?e a permis de d?terminer les profils microbiens sp?cifiques des diff?rentes r?gions ?tudi?es. Conclusion. Nous proposons d?utiliser la m?thode de la PCR-DGGE comme un nouvel outil de tra?abilit? qui fournirait un code barres unique aux produits issus d?agrumes et permettrait de relier les agrumes ? leur zone de culture originale. [ABSTRACT FROM AUTHOR]