Sequencing orphan species initiative (SOS): Filling the gaps in the 16S rRNA gene sequence database for all species with validly published names.

High quality 16S ribosomal RNA (rRNA) gene sequences from the type strains of all species with validly published names, as defined by the International Code of Nomenclature of Bacteria, are a prerequisite for their accurate affiliations within the global genealogical classification and for the recognition of potential new taxa. During the last few years, the Living Tree Project (LTP) has taken care to create a high quality, aligned 16S and 23S rRNA gene sequence database of all type strains. However, the manual curation of the sequence dataset and type strain information revealed that a total of 552 "orphan" species (about 5.7% of the currently classified species) had to be excluded from the reference trees. Among them, 322 type strains were not represented by an SSU entry in the public sequence repositories. The remaining 230 type strains had to be discarded due to bad sequence quality. Since 2010, the LTP team has coordinated a network of researchers and culture collections in order to improve the situation by (re)-sequencing the type strains of these "orphan" species. As a result, we can now report 351 16S rRNA gene sequences of type strains. Nevertheless, 201 species could not be sequenced because cultivable type strains were not available (121), the cultures had either been lost or were never deposited in the first place (66), or it was not possible due to other constraints (14). The International Code of Nomenclature of Bacteria provides a number of mechanisms to deal with the problem of missing type strains and we recommend that due consideration be given to the appropriate mechanisms in order to help solve some of these issues.

Proposal of Heliobacteriaceae fam. nov.

The family name Heliobacteriaceae is not validly published. The purpose of this note is to provide a description of this family in accordance with the Rules of the Bacteriological Code (1990 Revision).

Proposal of Frondihabitans gen. nov. to replace the illegitimate genus name Frondicola Zhang et al. 2007.

The prokaryotic generic name Frondicola Zhang et al. 2007 is illegitimate because it is a later homonym of a fungal genus name Frondicola Hyde, 1992 (Fungi, Ascomycota, Sordariomycetes, Xylariomycetidae, Xylariales, Hyponectriaceae) [Principle 2 and Rule 51b(4) of the Bacteriological Code (1990 Revision)]. It is also questionable whether the genus name can be validly published. Therefore, a new genus name, Frondihabitans gen. nov., is proposed for this taxon. As a result, a new name is proposed for the type species, Frondihabitans australicus sp. nov., to replace the illegitimate combination Frondicola australicus Zhang et al. 2007. The type strain of Frondihabitans australicus is E1HC-02(T) (=JCM 13598(T) =DSM 17894(T)).

Proposal of Yaniellaceae fam. nov., Yaniella gen. nov. and Sinobaca gen. nov. as replacements for the illegitimate prokaryotic names Yaniaceae Li et al. 2005, Yania Li et al. 2004, emend Li et al. 2005, and Sinococcus Li et al. 2006, respectively.

The prokaryotic generic names Yania Li et al. 2004 and Sinococcus Li et al. 2006 are illegitimate because they are later homonyms of the names Yania Roewer 1919 (Opiliones, Arachnida, Arthropoda, Animalia), Yania Huang 1997 (Lepidoptera: Hesperiidae) and Sinococcus Wu and Zheng 2000 (Homoptera: Coccomorpha) [Principle 2 of the Bacteriological Code (1990 Revision)]. Therefore, new generic names, Yaniella gen. nov. and Sinobaca gen. nov., are proposed for these taxa. In addition, a new family name, Yaniellaceae fam. nov., is proposed to accommodate Yaniella gen. nov. As a result, new combinations are required for the species to replace the illegitimate species names.

Proposal to replace the illegitimate genus name Schineria Toth et al. 2001 with the genus name Ignatzschineria gen. nov. and to replace the illegitimate combination Schineria larvae Toth et al. 2001 with Ignatzschineria larvae comb. nov.

The prokaryotic, generic name Schineria Tóth et al. 2001 is illegitimate owing to the prior existence of the name Schineria for a genus within the Diptera [Principle 2, Rule 51b(4) of the Bacteriological Code (1990 Revision)]. Therefore, a new genus name, Ignatzschineria gen. nov., is proposed for this taxon. As a result, a new combination is required for the type species, Ignatzschineria larvae comb. nov., to replace the illegitimate combination Schineria larvae Tóth et al. 2001.

Valid publication of names of prokaryotes according to the rules of nomenclature: past history and current practice.

It is now 30 years since the concept of valid publication was introduced into prokaryote systematics in such a way that a system of registration/indexing was integrated. Despite the success of this system and the introduction of the Approved Lists of Bacterial Names, accompanied by a new starting date in prokaryote nomenclature, there is a need to review both the historical aspects and current practices so that the current generation of prokaryote systematists have an up-to-date overview of some of the key elements.

Redefining Paracoccus denitrificans and Paracoccus pantotrophus and the case for a reassessment of the strains held by international culture collections.

An outline of the current taxonomic diversity of the genus Paracoccus is presented. A definitive summary is given of the valid type strains of Paracoccus denitrificans and Paracoccus pantotrophus and of culture collection strains that can be assigned to these species. The case is established for a critical reassessment of the P. denitrificans strains held by international culture collections, to ensure that they are assigned to the correct species.