RESUMO
Gemmata obscuriglobus is a Gram-negative bacterium with several intriguing biological features. Here, we present a complete, de novo whole genome assembly for G. obscuriglobus which consists of a single, circular 9 Mb chromosome, with no plasmids detected. The genome was annotated using the NCBI Prokaryotic Genome Annotation pipeline to generate common gene annotations. Analysis of the rRNA genes revealed three interesting features for a bacterium. First, linked G. obscuriglobus rrn operons have a unique gene order, 23S-5S-16S, compared to typical prokaryotic rrn operons (16S-23S-5S). Second, G. obscuriglobus rrn operons can either be linked or unlinked (a 16S gene is in a separate genomic location from a 23S and 5S gene pair). Third, all of the 23S genes (5 in total) have unique polymorphisms. Genome analysis of a different Gemmata species (SH-PL17), revealed a similar 23S-5S-16S gene order in all of its linked rrn operons and the presence of an unlinked operon. Together, our findings show that unique and rare features in Gemmata rrn operons among prokaryotes provide a means to better define the evolutionary relatedness of Gemmata species and the divergence time for different Gemmata species. Additionally, these rrn operon differences provide important insights into the rrn operon architecture of common ancestors of the planctomycetes.
Assuntos
Genoma Bacteriano/genética , Óperon/genética , Planctomycetales/genética , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Óperon de RNAr/genéticaRESUMO
Isodados de Xanthomonas campestris foram adaptados à utilizaçäo de lactose para produçäo de xantana. Um meio mínimo de soro de leite (sem desproteinizaçäo e hidrólise) foi desenvolvido contendo 0,5 por cento K2HPO4; 0,01 por cento MgSO4 e 4 por cento leite gerando 14Kg/10 de goma. A viscosidade de soluçöes das gomas obtidas pelos isolados também foi avaliada
