Whole-genome analysis of the ammonia-oxidizing bacterium, Nitrosomonas eutropha C91: implications for niche adaptation.
Analysis of the structure and inventory of the genome of Nitrosomonas eutropha C91 revealed distinctive features that may explain the adaptation of N. eutropha-like bacteria to N-saturated ecosystems. Multiple gene-shuffling events are apparent, including mobilized and replicated transposition, as well as plasmid or phage integration events into the 2.66 Mbp chromosome and two plasmids (65 and 56 kbp) of N. eutropha C91. A 117 kbp genomic island encodes multiple genes for heavy metal resistance, including clusters for copper and mercury transport, which are absent from the genomes of other ammonia-oxidizing bacteria (AOB). Whereas the sequences of the two ammonia monooxygenase and three hydroxylamine oxidoreductase gene clusters in N. eutropha C91 are highly similar to those of Nitrosomonas europaea ATCC 19718, a break of synteny in the regions flanking these clusters in each genome is evident. Nitrosomonas eutropha C91 encodes four gene clusters for distinct classes of haem-copper oxidases, two of which are not found in other aerobic AOB. This diversity of terminal oxidases may explain the adaptation of N. eutropha to environments with variable O(2) concentrations and/or high concentrations of nitrogen oxides. As with N. europaea, the N. eutropha genome lacks genes for urease metabolism, likely disadvantaging nitrosomonads in low-nitrogen or acidic ecosystems. Taken together, this analysis revealed significant genomic variation between N. eutropha C91 and other AOB, even the closely related N. europaea, and several distinctive properties of the N. eutropha genome that are supportive of niche specialization.
Stein
Lisa Y
LY
Department of Environmental Sciences, University of California, Riverside, CA 92521, USA. lisa.stein@ucr.edu
Arp
Daniel J
DJ
Berube
Paul M
PM
Chain
Patrick S G
PS
Hauser
Loren
L
Jetten
Mike S M
MS
Klotz
Martin G
MG
Larimer
Frank W
FW
Norton
Jeanette M
JM
Op den Camp
Huub J M
HJ
Shin
Maria
M
Wei
Xueming
X
D000222:Adaptation, Physiological; D000641:Ammonia / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D017753:Ecosystem; D005068:Eutrophication; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D009589:Nitrogen Oxides / Q000378:metabolism / Q000494:pharmacology; D009606:Nitrosomonas / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D043370:Nitrosomonas europaea / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000494:pharmacology
D001426:Bacterial Proteins; D009589:Nitrogen Oxides; D000641:Ammonia; D010100:Oxygen