This article publishes Validation List No. 77, which formally validates new bacterial names and combinations previously published elsewhere. The International Journal of Systematic and Evolutionary Microbiology uses this procedure to establish official nomenclatural status for microbial taxa described in other journals. The list includes seven new names: the genus Ferribacterium and its type species F. limneticum (an iron-reducing bacterium from lake sediments), two methylotrophic species (Methylopila helvetica and Methylobacterium dichloromethanicum) that utilize dichloromethane, two actinomycete species from Antarctic lake sediments (Friedmanniella lacustris and Nocardioides aquaticus), a reclassification of Pseudomonas oxalaticus as Ralstonia oxalaticus, and the new family Sphingomonadaceae. The valid publication date is the validation list date, not the original publication date. Each entry includes strain designations and culture collection accession numbers. Notably, validation does not constitute taxonomic acceptance; these organisms may later be reclassified or shown to be synonymous with existing species.

Key findings

• Seven new bacterial taxa were formally validated including one new genus (Ferribacterium), four new species, one nomenclatural reclassification, and one new family (Sphingomonadaceae)
• Validated organisms include iron-reducing bacteria, dichloromethane-utilizing methylotrophs, and actinomycetes from various environmental sources
• The valid publication date is the validation list date, not the date of original description in other journals
• Validation establishes nomenclatural availability but does not constitute taxonomic acceptance of the taxa