Paenibacillus pasadenensis sp. nov. and Paenibacillus barengoltzii sp. nov., isolated from a spacecraft assembly facility

Abstract

Two novel spore-forming, Gram-positive, mesophilic, heterotrophic bacteria representing two novel species were isolated from the Jet Propulsion Laboratory Spacecraft Assembly Facility (JPL-SAF) at Pasadena, CA, USA. The incidence of similar strains was examined by screening the growing collection of isolates (~400 strains) obtained from the JPL-SAF using species-specific PCR primer sets designed from the 16S rRNA gene sequences of strains SAFN-016T and SAFN-007T. Phylogenetic analysis of 16S rRNA gene sequences placed these novel isolates within the genus Paenibacillus. Two strains, SAFN-016T and SAFN-125, shared 98 % 16S rRNA gene sequence similarity with Paenibacillus timonensis and 97 % similarity with Paenibacillus macerans. Strain SAFN-007T showed 95.2 % 16S rRNA gene sequence similarity with Paenibacillus kobensis, its nearest phylogenetic neighbour. The results of DNA–DNA hybridization, physiological tests and biochemical analysis allowed genotypic and phenotypic differentiation of the isolates from currently recognized Paenibacillus species. Strain SAFN-007T and strains SAFN-016T and SAFN-125 are representatives of two separate novel species, for which the names Paenibacillus pasadenensis sp. nov. (type strain SAFN-007T=ATCC BAA-1211T=NBRC 101214T) and Paenibacillus barengoltzii sp. nov. (type strain SAFN-016T=ATCC BAA-1209T=NBRC 101215T) are proposed.