Nitrosospira lacus

Classification

Higher order taxa

Domain Bacteria; Phylum Proteobacteria; Class Betaproteobacteria; Order Nitrosomonadales; Family nitrosomonadaceae; Genus Nitrosospira;

Species

Nitrosospira lacus APG3T = NCIMB 14869T = LMG 27536T = ATCC BAA-2542T

Description and significance

Nitrosospira lacus is the 4th Nitrosospira species described. It is a sole representative of Cluster 0 Nitrosospira. APG3T was isolated from a shallow lake sediment in 2008 (Green Lake, WA, USA). Strain APG3T can grow at 4 °C but cannot grow at 35 °C, indicating that this bacterium is psychrotolerant. It should be noted that the strain is able to grow over a wide range of pH (pH 5–9), which is greater than the pH range of any previously reported ammonia-oxidizing bacteria in pure culture. However, the optimum pH is between 7.0 to 8.0, thus, APG3T is acid tolerant and not acidophilic. Some ammonia-oxidizing archaea show better adaptation to low pH soil environments (Lehtovirta-Morley et al. 2011). One another unique feature of this bacterium is that N. lacus is only Nitrosospira species that can grow at 4C. Thus, this bacterium is psychrotolerant.

16S Ribosomal RNA Gene Information

Phylogenetic analysis based on the 16S rRNA gene sequence showed that Nitrosospira multiformis (cluster 3) as the closest species with a validly published name (identity of 98.6 % to the type strain).

Genome Structure (if the genome exists)

The draft genome sequence comprises 3,107,181 bases, which is similar to the genome size of Nitrosospira multiformis ATCC 25196T (3.2 Mbp) but larger than the genomes of Nitrosomonas europaea ATCC 19718 (2.8 Mbp) and Nitrosomonas eutropha C71 (2.8 Mbp). The reported draft genome consists of 84 contigs with an average size of 41,181 bp. The DNA G+C content (53.6%) is similar to the G+C content of the genome of Nitrosospira multiformis ATCC 25196T (53.9%), but higher than that of Nitrosomonas europaea ATCC 19718 (50.7%) and Nitrosomonas eutropha C71 (48.5%). The draft genome contains 3147 protein-coding DNA sequences, 44 tRNA genes and a single 16S–23S–5S rRNA operon.

References

Urakawa, H., Garcia, J.C., Nielsen, J.L., Le, V.Q., Kozlowski, J.A., Stein, L.Y., Lim, C.K., Pommerening-Roeser, A., Martens-Habbena, W., Stahl, D.A. and Klotz, M.G., 2015. Nitrosospira lacus sp. nov., a psychrotolerant, ammonia-oxidizing bacterium from sandy lake sediment. International journal of systematic and evolutionary microbiology, 65(Pt_1), pp.242-250.

Lehtovirta-Morley, L.E., Stoecker, K., Vilcinskas, A., Prosser, J.I. and Nicol, G.W., 2011. Cultivation of an obligate acidophilic ammonia oxidizer from a nitrifying acid soil. Proceedings of the National Academy of Sciences, 108(38), pp.15892-15897.