The taxonomic status of Paenibacillus thermophilus was analyzed using genomic and phenotypic approaches. The results of RNA polymerase beta subunit gene sequence comparisons indicated that two type strains of P. thermophilus (DSM 24746T and JCM 17693T) and Paenibacillus macerans ATCC 8244T shared 100 % sequence similarity. By whole-genome sequence comparison, their average nucleotide identity values were over 99.3 %. Investigation of substrate utilization, enzyme activities and cellular fatty acid patterns displayed no striking differences between P. thermophilus JCM 17693T and P. macerans JCM 2500T. On the basis of these results, we propose that the name Paenibacillus thermophilus is a later heterotypic synonym of Paenibacillus macerans.
Keywords: Paenibacillus macerans; Paenibacillus thermophilus; genome analysis; heterotypic synonym; multilocus sequence analysis.