The current picture of bacterial evolution is based largely on studies of 16S rRNA. However, this is just one gene. It is known that horizontal gene transfer can occur between bacterial species, although the frequency and implications of this are not fully understood. If horizontal transfer were frequent, there would be no single evolutionary tree for bacteria because each gene would follow a d...

Horizontal gene transfer (HGT) of operational genes has been widely reported in prokaryotic organisms. However, informational genes such as those involved in transcription and translation processes are very difficult to be horizontally transferred, as described by Woese's complexity hypothesis. Here, we analyzed all of the completed prokaryotic genome sequences (2,143 genomes) in the NCBI (Nati...

To examine the flexibility of rRNA operons with respect to fundamental organization, transcription, processing, and assembly of ribosomes, operon variations were introduced by a plasmid into an Escherichia coli strain that has deletions of all chromosomal copies of rRNA genes. In the reconstructed operons, a Salmonella intervening sequence (IVS) from 23S helix 45 was introduced into the E. coli...

The acI lineage of freshwater Actinobacteria is a cosmopolitan and often numerically dominant member of lake bacterial communities. We conducted a survey of acI 16S rRNA genes and 16S-23S rRNA internal transcribed spacer regions from 18 Wisconsin lakes and used standard nonphylogenetic and phylogenetic statistical approaches to investigate the factors that determine acI community composition at...

in this research the effects of crude oil on morphological and physiological characterization ofthe cyanobacterium microchaete tenera isc13 were investigated. isolated cyanobacterium treated with different oil concentrations (control, 1, 2.5, 5 and 7%) in carbonless bg110 medium. morphological characteristics such as morphology of filament, cellular shapes and sizes, relative position of hetero...

background and objectives: the development of molecular biological techniques provide a method for direct detection and identification of pathogens. this study attempted to compare bacterial culture and pcr to detect s. agalactiae in cattle milk samples. the pcr method was based on using primers v1 and v2 derived from the 16s rrna gene. materials and methods: one hundred milk samples were colle...