Stress response of a marine ammonia-oxidizing archaeon informs physiological status of environmental populations.

High representation by ammonia-oxidizing archaea (AOA) in marine systems is consistent with their high affinity for ammonia, efficient carbon fixation, and copper (Cu)-centric respiratory system. However, little is known about their response to nutrient stress. We therefore used global transcriptional and proteomic analyses to characterize the response of a model AOA, Nitrosopumilus maritimus SCM1, to ammonia starvation, Cu limitation and Cu excess.

Cycloheximide prevents the de novo polypeptide synthesis required to recover from acetylene inhibition in Nitrosopumilus maritimus.

Developing methods to differentiate the relative contributions of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) to ammonia (NH3) oxidation has been challenging due to the lack of compounds that selectively inhibit AOA. In this study, we investigated the effects of specific bacteria- and eukaryote-selective protein synthesis inhibitors on the recovery of acetylene (C2H2)-inactivated NH3 oxidation in the marine AOA Nitrosopumilus maritimus and compared the results with recovery of the AOB Nitrosomonas europaea. C2 H2 irreversibly inhibited N.

Use of aliphatic n-alkynes to discriminate soil nitrification activities of ammonia-oxidizing thaumarchaea and bacteria.

Ammonia (NH3)-oxidizing bacteria (AOB) and thaumarchaea (AOA) co-occupy most soils, yet no short-term growth-independent method exists to determine their relative contributions to nitrification in situ. Microbial monooxygenases differ in their vulnerability to inactivation by aliphatic n-alkynes, and we found that NH3 oxidation by the marine thaumarchaeon Nitrosopumilus maritimus was unaffected during a 24-h exposure to ≤ 20 μM concentrations of 1-alkynes C8 and C9. In contrast, NH3 oxidation by two AOB (Nitrosomonas europaea and Nitrosospira multiformis) was quickly and irreversibly inactivated by 1 μM C8 (octyne).

Hydroxylamine as an intermediate in ammonia oxidation by globally abundant marine archaea.

The ammonia-oxidizing archaea have recently been recognized as a significant component of many microbial communities in the biosphere. Although the overall stoichiometry of archaeal chemoautotrophic growth via ammonia (NH(3)) oxidation to nitrite (NO(2)(-)) is superficially similar to the ammonia-oxidizing bacteria, genome sequence analyses point to a completely unique biochemistry. The only genomic signature linking the bacterial and archaeal biochemistries of NH(3) oxidation is a highly divergent homolog of the ammonia monooxygenase (AMO).

Global analysis of the Nitrosomonas europaea iron starvation stimulon.

The importance of iron to the metabolism of the ammonia-oxidizing bacterium Nitrosomonas europaea is well known. However, the mechanisms by which N. europaea acquires iron under iron limitation are less well known.

Role of a Fur homolog in iron metabolism in Nitrosomonas europaea.

Background: In response to environmental iron concentrations, many bacteria coordinately regulate transcription of genes involved in iron acquisition via the ferric uptake regulation (Fur) system. The genome of Nitrosomonas europaea, an ammonia-oxidizing bacterium, carries three genes (NE0616, NE0730 and NE1722) encoding proteins belonging to Fur family.

Results: Of the three N.

Dissecting iron uptake and homeostasis in Nitrosomonas europaea.

The chemolithoautotroph Nitrosomonas europaea oxidizes about 25 mol of NH(3) for each mole of CO(2) that is converted to biomass using an array of heme and nonheme Fe-containing proteins. Hence mechanisms of efficient iron (Fe) uptake and homeostasis are particularly important for this Betaproteobacterium. Among nitrifiers, N.

Computational prediction and transcriptional analysis of sRNAs in Nitrosomonas europaea.

Bacterial small noncoding RNAs (sRNAs) have been discovered in many genetically well-studied microorganisms and have been shown to regulate critical cellular processes at the post-transcriptional level. In this study, we used comparative genomics and microarray data to analyze the genome of the ammonia-oxidizing bacterium Nitrosomonas europaea for the presence and expression of sRNAs. Fifteen genes encoding putative sRNAs (psRNAs) were identified.

Role of Nitrosomonas europaea NitABC iron transporter in the uptake of Fe3+-siderophore complexes.

Nitrosomonas europaea has a single three-gene operon (nitABC) encoding an iron ABC transporter system (NitABC). Phylogenetic analysis clustered the subunit NitB with Fe(3+)-ABC transporter permease components from other organisms. The N.

Iron nutrition and physiological responses to iron stress in Nitrosomonas europaea.

Nitrosomonas europaea, as an ammonia-oxidizing bacterium, has a high Fe requirement and has 90 genes dedicated to Fe acquisition. Under Fe-limiting conditions (0.2 microM Fe), N.