Paenibacillus piscarius sp. nov., a novel nitrogen-fixing species isolated from the gut of the armored catfish Parotocinclus maculicauda

• Published in: Antonie van Leeuwenhoek 2022, Vol.115 (1), p.155-165
• Main Authors: da Silva, Mariana Barbalho Farias, Lemos, Ericka Arregue, Vollú, Renata E., Abreu, Fernanda, Rosado, Alexandre S., Seldin, Lucy
• Format: Article
• Language: English
• Subjects: Animals; Biomedical and Life Sciences; Catfish; Catfishes; Deoxyribonucleic acid; DNA; DNA sequencing; DNA, Bacterial - genetics; Fatty acids; Gene sequencing; Genes; Genomes; Hybridization; Life Sciences; Medical Microbiology; Microbiology; New species; NifH gene; Nitrogen; Nitrogen fixation; Nitrogenase; Nitrogenation; Nucleotides; Original Paper; Paenibacillus; Paenibacillus - genetics; Parotocinclus maculicauda; Phylogeny; Plant Sciences; Quinones; RNA, Ribosomal, 16S - genetics; RpoB protein; rRNA 16S; Soil Science & Conservation
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-021-01694-5

A Gram-positive, nitrogen-fixing and endospore-forming strain, designated P121 T , was isolated from the gut of the armored catfish ( Parotocinclus maculicauda ) and identified as a member of the genus Paenibacillus based on the sequences of the 16S rRNA encoding gene, rpoB , gyrB and nifH genes and phenotypic analyses. The most closely related species to strain P121 T were Paenibacillus rhizoplanae DSM 103993 T , Paenibacillus silagei DSM 101953 T and Paenibacillus borealis DSM 13188 T , with similarity values of 98.9, 98.3 and 97.6%, respectively, based on 16S rRNA gene sequences. Genome sequencing revealed a genome size of 7,513,698 bp, DNA G + C content of 53.9 mol% and the presence of the structural nitrogenase encoding genes ( nifK , nifD and nifH ) and of other nif genes necessary for nitrogen fixation. Digital DNA-DNA hybridization (dDDH) experiments and average nucleotide identity (ANI) analyses between strain P121 T and the type strains of the closest species demonstrated that the highest values were below the thresholds of 70% dDDH (42.3% with P. borealis ) and 95% ANI (84.28% with P. silagei ) for bacterial species delineation, indicating that strain P121 T represents a distinct species. Its major cellular fatty acid was anteiso-C 15:0 (42.4%), and the major isoprenoid quinone was MK-7. Based on physiological, genomic, biochemical and chemotaxonomic characteristics, we propose that strain P121 T represents a novel species for which the name Paenibacillus piscarius sp. nov. is proposed (type strain = DSM 25072 = LFB-Fiocruz 1636).