Recently, two strains of Schlegelella thermodepolymerans Elbanna et al. 2003 and an independently isolated bacterium, Caenibacterium thermophilum Manaia et al. 2003, were described in parallel as gen. nov., sp. nov. Analysis of the 16S rRNA genes revealed similarity between C. thermophilum and the two strains of S. thermodepolymerans of 99.8 and 99.6 %, respectively. DNA-DNA hybridization experiments revealed mean DNA reassociation levels of 97-98 % among C. thermophilum and the two strains of S. thermodepolymerans, thereby confirming the close relationship and indicating that C. thermophilum is a later synonym of S. thermodepolymerans.