International Journal of Systematic and Evolutionary Microbiology

The International Journal of Systematic and Evolutionary Microbiology (IJSEM) is a peer-reviewed academic journal in the field of microbial systematics, first published in 1951. Its scope covers the taxonomy, nomenclature, identification, characterisation, culture preservation, phylogeny, evolution and biodiversity of all microorganisms, including prokaryotes, yeasts and yeast-like organisms, protozoa and algae. IJSEM is currently published monthly by the Society for General Microbiology, Reading, UK.

An official publication of the International Committee on Systematics of Prokaryotes (ICSP; formerly the International Committee on Systematic Bacteriology) and of the International Union of Microbiological Societies (Bacteriology and Applied Microbiology Division), the journal is the single official international forum for the publication of new species names for prokaryotes. In addition to research papers, IJSEM also publishes the minutes of meetings of the ICSP and its various subcommittees.

As of 2007, the Editor-in-Chief is Peter Kämpfer (Justus Liebig-Universität Giessen, Germany) and the Lists Editor is Jean P. Euzéby (École Nationale Vétérinaire, Toulouse, France). The journal's 2006 impact factor was 2.662, and it lies seventh in the ranking of primary (non-review) journals in microbiology.

IJSEM content from 1995 is available online as PDFs, and also in text format from 2003. Papers over 2 years old are currently available freely.

Background and history
From the first identification of a bacterial species in 1872, microbial species were named according to the binomial nomenclature, based on largely subjective descriptive characteristics. By the end of the 19th century, however, it was clear that this nomenclature and classification system required reform. Although several different comprehensive nomenclature systems were invented (most notably, that described in Bergey's Manual of Determinative Bacteriology, first published in 1923), none gained international recognition. In 1930, a single international body, now named the International Committee on Systematics of Prokaryotes (ICSP), was established to oversee all aspects of prokaryotic nomenclature. Work began in 1936 on drafting a Code of Bacteriological Nomenclature, the first version of which was approved in 1947.

In 1950, at the 5th International Congress for Microbiology, a journal was founded to disseminate the committee's conclusions to the microbiological community. It first appeared the following year under the title of International Bulletin of Bacteriological Nomenclature and Taxonomy. In 1980, the ICSP published an exhaustive list of all existing bacterial species considered valid in the Approved Lists of Bacterial Names. Thereafter, the committee's Code required all new names to be either published or indexed in its journal to be deemed valid.

The journal was at first published by Iowa State College Press, USA, with a quarterly publication frequency, which later increased to bimonthly. In 1966, the journal was renamed the International Journal of Systematic Bacteriology. The cover at one point bore a quotation from Mueller: "the sure and definite determination (of species of bacteria) requires so much time, so much acumen of eye and judgement, so much of perseverance and patience that there is hardly anything else so difficult." Between 1971 and the end of 1997, the journal was published by the American Society for Microbiology.

Publication moved to the UK in 1998, the journal being taken over by the Society for General Microbiology (SGM), in conjunction with Cambridge University Press. The title was changed to International Journal of Systematic and Evolutionary Microbiology in 2000, to reflect the broadened focus of the journal. A major redesign brought the journal into line with the three other SGM journals in 2003, and at the same date the printer/typesetter changed to the Charlesworth Group. The frequency increased to monthly in 2006.

Role in nomenclature validation
IJSEM is the official international forum for the publication of new prokaryotic taxa, from subspecies to class. The journal publishes research papers establishing novel prokaryotic names, which are summarised in a notification list. Each monthly issue also contains a compilation of validated new names (the validation list) that have been previously published in other scientific journals or books. Since August 2002, publications relating to new bacterial taxa and validation of publication elsewhere have both required type strains to have been deposited at two recognised public collections in different countries.

Under the latest version of the ICSP's International Code of Nomenclature of Prokaryotes, all new names must be published or indexed in the journal to be deemed valid. As of 2007, the journal has officially validated around 6500 species and 1500 genera. It was estimated in 2004 that over 300 new names had been published but not validated.

Key paper

 * Fox GE, Pechman KR, Woese CR. (1977) Comparative cataloging of 16S ribosomal ribonucleic acid: molecular approach to procaryotic systematics Int J Syst Bacteriol 27: 44–57 — The first reconstruction of phylogenetic relationships in Bacillus based on 16S rRNA sequences, this paper paved the way for the modern understanding of the evolutionary relationships among prokaryotes.