Phylogenetic tree analysis of Youhaiella tibetensis F4T, Paradevosia shaoguanensis J5-3T and Methyloterrigena soli M48T based on 16S rRNA gene sequences revealed that the three genera did not form distinct and independent monophyletic clusters. The 16S rRNA gene sequence similarities were all higher than 99 % between each pair of the three type strains. Average nucleotide identity, digital DNA-DNA hybridization, average amino acid identity and 16S rRNA gene sequence similarity between Paradevosia shaoguanensis J5-3T and Methyloterrigena soli M48T showed that they represented the same species. Physiological and biochemical characteristics of these three strains were similar, such as motility by polar flagella, major respiratory quinone, polar lipids, and fatty acids. Polygenetic trees and other characteristic comparative analysis revealed the need to merge the genera Youhaiella and Paradevosia into one genus.