Metagenome-Assembled Genome of USCα AHI, a Potential High-Affinity Methanotroph from Axel Heiberg Island, Canadian High Arctic.

Metagenomic sequencing of active-layer cryosols from the Canadian High Arctic has yielded a nearly complete genome for an atmospheric CH4-oxidizing bacterium belonging to upland soil cluster α (USCα). This genome contains genes involved in CH4 metabolism, H2 metabolism, and multiple carbon assimilation pathways.

R ecent studies have shown that mineral cryosols from the Canadian High Arctic Axel Heiberg Island (AHI) act as CH 4 sinks during the summer (1), drawing CH 4 from both the atmosphere and underlying hypoxic cryosols (2,3), and harbor metabolically active upland soil cluster ␣ (USC␣) proteobacteria (1). Twenty-one metagenomic data sets of active-layer cryosols (4) from long-term core incubation experiments were used to construct the draft genome of this USC␣. Sequencing and sample collection methods were published by Chauhan et al. (4).
The USC␣ AHI genome belongs within the Beijerinckiaceae (Fig. 1) and possesses a 416-nt-long 16S rRNA gene that is 98.1 to 98.6% similar to published USC␣ 16S rRNA genes (10,17). Its pmoA and pmoB genes match 99.7 to 100% with DNA and RNA sequences previously reported from AHI that were phylogenetically determined as the high-affinity form for CH 4 oxidation (1). USC␣ AHI is able to assimilate C from CH 4 and from CO 2 via the serine cycle, the reductive glycine pathway, and the Calvin-Benson-Bassham cycle. USC␣ AHI can utilize various carbon sources via the pentose phosphate and Entner-Doudoroff pathways, including acetate in its tricarboxylic acid (TCA) cycle, although the acetate transporter gene (actP) is absent. The [NiFe] group 1h hydrogenase for H 2 metabolism is also present.
Data availability. The draft genome sequence of USC␣ AHI has been deposited at NCBI GenBank under the accession number VDMG00000000 (BioSample number SAMN11877018 and BioProject number PRJNA545288). The version described in this paper is VDMG01000000. The raw reads of 21 metagenomes have been deposited at the NCBI Sequence Read Archive under the accession number SRP047512 (4).

ACKNOWLEDGMENTS
The sequencing was supported by U.S. Department of Energy grant DE-SC0004902 to S.M.P.
We thank the Princeton University Research Computing Office of Information Technology staff for their support with the computational analyses and the GEO523 2016 class for filtering the metagenomic reads on the Galaxy platform.
M.C.Y.L. conceived the analysis. T.A.V. performed the total DNA extraction and submitted it to A.L. and A.C. for sequencing. A.C. and A.L. performed the initial quality filtering. C.R. and M.C.Y.L. assembled the sequenced reads. C.R. performed the mapping, binning, reassembly, gene prediction, and annotation with consultation from M.C.Y.L., and C.R., M.C.Y.L., and T.C.O. contributed to the interpretation of the data and production of the manuscript.
We declare no conflict of interest.