sp. nov., a novel type II methanotrophic bacterium isolated from landfill cover soil.

A bacterial strain, designated NLS-7, was isolated through enrichment of landfill cover soil in methane-oxidizing conditions. Strain NLS-7 is a Gram-stain negative, non-motile rod, approximately 0.8 µm wide by 1.3 µm long. Phylogenetic analysis based on 16S rRNA gene sequencing places it within the genus , with its closest relatives being , and , with 99.9, 99.7 and 99.6 % sequence similarity respectively. However, average nucleotide identity and average amino acid identity values below the 95 % threshold compared to all the close relatives and digital DNA-DNA hybridization values between 20.9 and 54.1 % demonstrate that strain NLS-7 represents a novel species. Genome sequencing generated 4.31 million reads and genome assembly resulted in the generation of 244 contigs with a total assembly length of 3 820 957 bp (N50, 37 735 bp; L50, 34). Genome completeness is 99.5 % with 3.98 % contamination. It is capable of growth on methane and methanol. It grows optimally at 30 °C between pH 6.5 and 7.0. Strain NLS-7 is capable of atmospheric dinitrogen fixation and can use ammonium (as NHCl), l-aspartate, l-arginine, yeast extract, nitrate, l-leucine, l-proline, l-methionine, l-lysine and l-alanine as nitrogen sources. The major fatty acids are C ω8 and C ω7. Based upon this polyphasic taxonomic study, strain NLS-7 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is NLS-7 (=ATCC TSD-256=DSM 112294). The 16S rRNA gene and genome sequences of strain NLS-7 have been deposited in GenBank under accession numbers ON715489 and GCA_024448135.1, respectively.