Abstract
Thiobacillus novellus is a facultatively chemolithoautotrophic and methylotrophic, Gram-negative, rod-shaped sulfur bacterium, shown by 16S rRNA gene sequence analysis to be a member of the alpha-2 subclass of the Proteobacteria. As such, it must be excluded from the genus Thiobacillus, whose species are members of the beta-Proteobacteria. It closest phylogenetic neighbour appears to be Ancylobacter, from which it is distinct morphologically and in some physiological characteristics. It is distinct physiologically and biochemically in a number of diagnostic features from Paracoccus versutus, in the alpha-3 subclass of the Proteobacteria and does not appear to be sufficiently closely related to any other genus of the alpha-Proteobacteria to be reassigned to a known genus. The new genus and species name Starkeya novella is proposed for T. novellus. The type strain is ATCC 8093(T) (=NCIMB 10456(T)=NCIMB 9113(T)=DSM 506(T)=IAM 12100(T)=IFO 12443(T)=CCM 1077(T)).