Physical and genetic map of the Weissella paramesenteroides DSMZ 20288T chromosome and characterization of different rrn operons by ITS analysis

The Weissella paramesenteroides DSMZ 20288T chromosome was analysed by pulsed-field gel electrophoresis, enabling the construction of a physical and genetic map. A total of 21 recognition sites of the restriction enzymes AscI, I-CeuI, NotI and SfiI were mapped on the chromosome, which was found to be circular with an estimated size of 2026 kb. This is believed to constitute the first study into the genomic organization of a strain of this genus, addressing the localization of important chromosomal regions such as oriC and terC. A total of 23 genetic markers were mapped, including eight rrn operons that were precisely assigned in 37 % of the W. paramesenteroides chromosome. The transcription direction of rrn loci was determined and three different rrn clusters were recognized regarding the presence/absence of tRNA genes in ITS regions.