Paenibacillus melissococcoides sp. nov., isolated from a honey bee colony affected by European foulbrood disease.

A novel, facultatively anaerobic, Gram- stain-positive, motile, endospore-forming bacterium of the genus Paenibacillus, des-ignated strain 2.1(T), was isolated from a colony of Apis mellifera affected by European foulbrood disease in Switzerland. The rod-shaped cells of strain 2.1(T) were 2.2-6.5 mu m long and 0.7-1.1 mu m wide. Colonies of strain 2.1(T) were orange-pigmented under oxic growth conditions on solid basal medium at 35-37 degrees C. Strain 2.1(T) showed catalase and cytochrome c oxidase activity. Its polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, aminophospholipid and phospholipid. The only respiratory quinone was menaquinone 7, and the major cellular fatty acids were anteiso-C15:0, anteiso-C17:0, iso-C15:0, iso-C17: 0 and palmitic acid (C16:0), which is consistent with other members of the genus Paenibacillus. The G+C content of the genomic DNA of strain 2.1(T) was 53.3 mol%. Phylogenetic analyses based on the 16S rRNA gene sequence similarity showed that strain 2.1(T) was closely related to Paenibacillus dendritiformis LMG 21716(T) (99.7 % similarity) and Pae-nibacillus thiaminolyticus DSM 7262(T) (98.8 %). The whole-genome average nucleotide identity between strain 2.1(T) and the type strains of P. dendritiformis and P. thiaminolyticus was 92 and 91 %, respectively, and thus lower than the 95 % threshold value for delineation of genomic prokaryotic species. Based on the results of phylogenetic, genomic, phenotypic and chemotaxonomic analyses we propose the name Paenibacillus melissococcoides sp. nov. for this novel Paenibacillus species. The type strain is 2.1(T) (=CCOS 2000(T)=DSM 113619(T)=LMG 32539(T)).