Desulfovibriovulgaris subsp. vulgaris is the correct name if this subspecies is regarded as a separate subspecies (i.e., if its nomenclatural type is not assigned to another subspecies whose name is validly published, legitimate and not rejected and has priority) within a separate species Desulfovibriovulgaris within a separate genus Desulfovibrio.
If an author accepts that Desulfovibrio vulgaris subsp. oxamicus Postgate and Campbell 1966 (Approved Lists 1980) is a new species [Desulfovibrio oxamicus (Postgate and Campbell 1966) López-Cortés et al. 2006, comb. nov.], then Desulfovibrio vulgaris subsp. vulgaris Postgate and Campbell 1966 (Approved Lists 1980) should thereafter be designated simply as Desulfovibrio vulgaris Postgate and Campbell 1966 (Approved Lists 1980).Publication:
Lopez-Cortes A, Fardeau ML, Fauque G, Joulian C, Ollivier B. Reclassification of the sulfate- and nitrate-reducing bacterium Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov. Int J Syst Evol Microbiol 2006; 56:1495-1499.