RESUMO
Aims: Pectobacterium carotovorum is a ubiquitous bacterium that causes soft rot in different crop plants throughout the world. In Morocco, approximately 95% of the Strains isolates from potato plants with tuber soft rot are P. carotovorum. In this study, we test whether PCR ribotyping can be used to distinguish strains of Pectobacterium carotovorum isolated from soft rot potato and to differentiate among strains from different geographic regions. Place and Duration of Study: Laboratory of Virology, Microbiology and Quality / Ecotoxicology and Biodiversity, department Biology, Faculty of Sciences and Techniques, University Hassan-II Mohammedia Casablanca. Methodology: Eighty-three pectolytic enterobacteria were collected from potatoes rotten in Morocco, the strains were isolated in the Cristal Violet Pectate (CVP) medium and were purified in LPGA agar (yeast extract, peptone, glucose and agar). After purification, strains were identified by physiological and biochemical tests. The confirmation of species was performed by PCR using primers Y1 and Y2. The genetic diversity of Pectobacterium carotovoum was investigated by PCR ribotyping using primers G1/L1, which are complementary to conserved regions of the rRNA operon. Furthermore, the profiles obtained were compared by the Unweighted Pair Group Method. Results: The biochemical and physiological analysis demonstrated that the predominant pectolytic enterobacterium present in Morocco is Pectobacterium carotovorum subsp carotovorum. The specific confirmation of species P. carotovorum by PCR has yielded a 434 bp DNA fragment of the pelY gene with all isolates. Further, PCR amplification of the 16S-23S Intergenic spacer Region (ITS-PCR) has presented a specific pattern made of 2-6 fragments ranging from 300 bp to 800 bp. The UPGMA tree has shown that there is considerable genetic diversity in P. carotovorum strains, which can be divided into four distinct groups.
RESUMO
En Colombia el cultivo de papa es el cuarto en importancia en la economía del país, y su producción alcanza las 300 millones de toneladas aproximadamente. Erwinia carotovora es una bacteria Gram negativa, anaeróbica facultativa causante de la pudrición blanda de la papa, puede llegar a generar hasta el 100% de daño en la cosecha, lo cual ocasiona grandes pérdidas económicas. Se ha establecido que la bacteria Bacillus thuringiensis es capaz de suprimir la virulencia de E. caratovora debido a que produce N-acil-homoserina-lactonasa, una potente enzima que degrada de N-acil-homoserinolactonas, que son indispensables en el mecanismo de quorum-sensing de E. caratovora. Esta circunstancia, puede ser una alternativa importante para el control de la enfermedad de la pudrición blanda de la papa. Considerando lo anterior, en este artículo se describe el proceso que emplea la bacteria Bacillus thuringiensis para inhibir la actividad de E. caratovora.
In Colombia the potato crop is the fourth in importance in the economy of the country, its production reached 300 million tons. Erwinia carotovora is a Gram-negative bacterium, facultative anaerobic which causes the soft rotting of the potato; it can potentially generate up to 100% damage in the crop, which causes large economic losses. It has been established that the bacterium Bacillus thuringiensis is able to suppress the virulence of E. caratovora because it produces N-acyl-homoserine-lactonasa, a powerful enzyme that degrades of N-acyl-homoserinolactonas, which are indispensable in the quorum-sensing mechanism of E. caratovora. This can be an important alternative for the control of the disease of the soft rotting of the potato. Considering the above, this article describes the process used by the bacterium B. thuringiensis to inhibit the activity of E. caratovora.