Transfer of Bacillus lentimorbus and Bacillus popilliae to the genus Paenibacillus with emended descriptions of Paenibacillus lentimorbus comb. nov, and Paenibacillus popilliae comb. nov.

Almost complete 16S rRNA gene sequences were generated for the type strains of the obligate insect pathogens Bacillus lentimorbus and Bacillus popilli ae and a second strain of Bacillus popilliae (NRRL B-4081) received as 'Bac illus popilliae var. melolonthae'. A phylogenetic tree was constructed whic h grouped these strains into a well defined subcluster within the genus Pae nibacillus. Bacillus popilliae NRRL B-4081 occupied an intermediate positio n between the type strains of Bacillus lentimorbus and Bacillus popilliae b ut with a marked clustering to the latter. The phylogenetic assignment of t hese strains to Paenibacillus is in contrast to earlier studies which place d these bacteria in the genus Bacillus, close to Bacillus subtilis. Indeed, the rRNA sequences generated in this study share less than 88% similarity to the deposited sequences for Bacillus popilliae ATCC 14706(T) and Bacillu s lentimorbus ATCC 14707(T). The results obtained by using different tree a lgorithms, bootstrap analysis, branch lengths and verification by signature nucleotide analysis supported the reclassification of these species in the genus Paenibacillus as Paenibacillus lentimorbus comb. nov. and Paenibacil lus popilliae comb, nov.