Virulence and avirulence genes carried on large, unstable pathogenicity islands (PAI) strongly influence the course and fate of host-pathogen interactions. A recent study shows how one such PAI can be rapidly transferred between two closely related bacteria via transformation in vivo, and how this horizontal gene transfer affects the fitness of the recipient strain.

We have developed a method to improve the transformation efficiency in genome-sequenced bacteria, using 'Plasmid Artificial Modification' (PAM), using the host's own restriction system. In this method, a shuttle vector was pre-methylated in Escherichia coli cells, which carry all the putative genes encoding the DNA modification enzymes of the target microorganism, before electroporation was per...

*Correspondence: Satoru Suzuki, Center for Marine Environmental Studies, Ehime University, Bunkyo-3, Matsuyama, Ehime 790-8577, Japan e-mail: [email protected] Proteins constitute the major portion of labile substances in the marine environment and are an important source of organic matter supporting marine ecosystems. However, previous studies have revealed that specific bacterial membrane...

Interspecies genetic exchange is an important evolutionary mechanism in bacteria. It allows rapid acquisition of novel functions by transmission of adaptive genes between related species. However, the frequency of homologous recombination between bacterial species decreases sharply with the extent of DNA sequence divergence between the donor and the recipient. In Bacillus and Escherichia, this ...

Partial duplication of genetic material is prevalent in eukaryotes and provides potential for evolution of new traits. Prokaryotes, which are generally haploid in nature, can evolve new genes by partial chromosome duplication, known as merodiploidy. Little is known about merodiploid formation during genetic exchange processes, although merodiploids have been serendipitously observed in early st...

There is little knowledge about microbial functional community structures and the relationships between communities nitrogen transformation processes. Here, we investigated soil mineralisation potentials in a cool temperate forest throughout growing season. Microbial were assessed by quantification of total bacterial, archaeal, fungal gene abundances bacterial archaeal amoA abundances, predicti...

Glacial alpine landscapes are undergoing rapid transformation due to changes in climate. The loss of glacial ice mass has directly influenced hydrologic characteristics of alpine floodplains. Consequently, hyporheic sediment conditions are likely to change in the future as surface waters fed by glacial water (kryal) become groundwater dominated (krenal). Such environmental shifts may subsequent...

The effects of ingestion of poorly digestible carbohydrates on bacterial transformations of cholic acid and beta-muricholic acid were studied in rats fed on increasing levels of lactose, lactulose, amylomaize or potato starches. Each level was given for 3 weeks and, at the end of each dietary treatment, bile acid faecal composition was analysed and a group of six rats was killed every 4 h durin...

Marine particles in the ocean are exposed to diverse bacterial communities, and colonization and growth of attached bacteria are important processes in the degradation and transformation of the particles. In an earlier study, we showed that the initial colonization of model particles by individual bacterial strains isolated from marine aggregates was a function of attachment and detachment. In ...