Aerobic nitrification is a key process in the global nitrogen cycle mediated by microorganisms. While nitrification has primarily been studied in near-neutral environments, this process occurs at a wide range of pH values, spanning ecosystems from acidic soils to soda lakes. Aerobic nitrification primarily occurs through the activities of ammonia-oxidising bacteria and archaea, nitrite-oxidising bacteria, and complete ammonia-oxidising (comammox) bacteria adapted to these environments. Here, we review the literature and identify knowledge gaps on the metabolic diversity, ecological distribution, and physiological adaptations of nitrifying microorganisms in acidic and alkaline environments. We emphasise that nitrifying microorganisms depend on a suite of physiological adaptations to maintain pH homeostasis, acquire energy and carbon sources, detoxify reactive nitrogen species, and generate a membrane potential at pH extremes. We also recognize the broader implications of their activities primarily in acidic environments, with a focus on agricultural productivity and nitrous oxide emissions, as well as promising applications in treating municipal wastewater.

• Klíčová slova
• archaea, metabolism, nitrification,
• MeSH
• amoniak * metabolismus   MeSH
• Bacteria metabolismus   MeSH
• ekosystém MeSH
• nitrifikace * MeSH
• oxidace-redukce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• amoniak * MeSH

Both plants and their associated arbuscular mycorrhizal (AM) fungi require nitrogen (N) for their metabolism and growth. This can result in both positive and negative effects of AM symbiosis on plant N nutrition. Either way, the demand for and efficiency of uptake of mineral N from the soil by mycorrhizal plants are often higher than those of nonmycorrhizal plants. In consequence, the symbiosis of plants with AM fungi exerts important feedbacks on soil processes in general and N cycling in particular. Here, we investigated the role of the AM symbiosis in N uptake by Andropogon gerardii from an organic source (15N-labeled plant litter) that was provided beyond the direct reach of roots. In addition, we tested if pathways of 15N uptake from litter by mycorrhizal hyphae were affected by amendment with different synthetic nitrification inhibitors (dicyandiamide [DCD], nitrapyrin, or 3,4-dimethylpyrazole phosphate [DMPP]). We observed efficient acquisition of 15N by mycorrhizal plants through the mycorrhizal pathway, independent of nitrification inhibitors. These results were in stark contrast to 15N uptake by nonmycorrhizal plants, which generally took up much less 15N, and the uptake was further suppressed by nitrapyrin or DMPP amendments. Quantitative real-time PCR analyses showed that bacteria involved in the rate-limiting step of nitrification, ammonia oxidation, were suppressed similarly by the presence of AM fungi and by nitrapyrin or DMPP (but not DCD) amendments. On the other hand, abundances of ammonia-oxidizing archaea were not strongly affected by either the AM fungi or the nitrification inhibitors. IMPORTANCE Nitrogen is one of the most important elements for all life on Earth. In soil, N is present in various chemical forms and is fiercely competed for by various microorganisms as well as plants. Here, we address competition for reduced N (ammonia) between ammonia-oxidizing prokaryotes and arbuscular mycorrhizal fungi. These two functionally important groups of soil microorganisms, participating in nitrification and plant mineral nutrient acquisition, respectively, have often been studied in separation in the past. Here, we showed, using various biochemical and molecular approaches, that the fungi systematically suppress ammonia-oxidizing bacteria to an extent similar to that of some widely used synthetic nitrification inhibitors, whereas they have only a limited impact on abundance of ammonia-oxidizing archaea. Competition for free ammonium is a plausible explanation here, but it is also possible that the fungi produce some compounds acting as so-called biological nitrification inhibitors.

• Klíčová slova
• Rhizophagus irregularis, ammonia-oxidizing archaea, ammonia-oxidizing bacteria, amplicon sequencing, arbuscular mycorrhiza, isotopic (15N) labeling and tracing, quantitative real-time PCR, synthetic nitrification inhibitor,
• MeSH
• amoniak metabolismus   MeSH
• amoniové sloučeniny * metabolismus   MeSH
• Archaea metabolismus   MeSH
• dusík metabolismus   MeSH
• jodid dimethylfenylpiperazinia metabolismus   farmakologie   MeSH
• kořeny rostlin metabolismus   MeSH
• mykorhiza * metabolismus   MeSH
• nitrifikace MeSH
• půda chemie   MeSH
• půdní mikrobiologie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amoniak MeSH
• amoniové sloučeniny * MeSH
• dicyandiamido MeSH Prohlížeč
• dusík MeSH
• jodid dimethylfenylpiperazinia MeSH
• půda MeSH

The nitrification of the liquid phase of digestate (LPD) was conducted using a 5L completely stirred tank reactor (CSTR) in two independent periods (P1 - without pH control; P2 - with pH control). The possibility of minimizing nitrogen losses during the application of LPD to the soil as well as during long-term storage or thermal thickening of LPD using nitrification was discussed. Moreover, the feasibility of applying the nitrification of LPD to the production of electron acceptors for biological desulfurization of biogas was assessed. Despite an extremely high average concentration of ammonia and COD in LPD reaching 2470 and 9080mg/L, respectively, nitrification was confirmed immediately after the start-up of the CSTR. N-NO3- concentration reached 250mg/L only two days after the start of P1. On the other hand, P1 demonstrated that working without pH control is a risk because of the free nitrous acid (FNA) inhibition towards nitrite oxidizing bacteria (NOB) resulting in massive nitrite accumulation. Up to 30.9mg/L of FNA was present in the reactor during P1, where the NOB started to be inhibited even at 0.15mg/L of FNA. During P2, the control of pH at 7.0 resulted in nitrogen oxidation efficiency reaching 98.3±1.5% and the presence of N-NO3- among oxidized nitrogen 99.6±0.4%. The representation of volatile free ammonia within total nitrogen was reduced more than 1000 times comparing with raw LPD under these conditions. Thus, optimum characteristics of the tested system from the point of view of minimizing the nitrogen losses as well as production of electron acceptors for the desulfurization of biogas were gained in this phase of reactor operation. Based on the results of the experiments, potential improvements and modifications of the tested system were suggested.

• Klíčová slova
• Digestate, Free nitrous acid, Inhibition, Liquid phase, Nitrification, Nutrients,
• MeSH
• amoniak MeSH
• bioreaktory * MeSH
• dusík MeSH
• dusitany MeSH
• nitrifikace * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amoniak MeSH
• dusík MeSH
• dusitany MeSH

Aquaponics is a method of producing food in a sustainable manner through the integration of aquaculture and hydroponics, which allows simultaneous cultivation of fish and economic crops. The use of natural fungicides are crucial to the sustainable control of diseases in aquaponics. We assessed the potential impacts of natural fungicides, such as clove oil and lecithin, as well as a synthetic fungicide, tebuconazole, following foliar application in aquaponics. This study examined the runoff rates of the fungicides in decoupled aquaponics, and the subsequent effects of the runoffs on nitrification processes and Nile tilapia (Oreochromis niloticus). The runoffs of the foliar-applied fungicides, clove oil, lecithin, and tebuconazole, were detected in aquaponics water at a percentage runoff rate of 0.3 %, 2.3 %, and 0.3-0.8 % respectively. In the biofilter, lecithin altered the ammonium levels by increasing ammonium-nitrogen levels by 7 mg L-1, 6 h post application. Clove oil, on the other hand, showed no significant effect on ammonium, nitrite, and nitrate-nitrogen. Similarly, the toxicity test showed that eugenol had no significant effects on the hematological, biochemical and antioxidative activities of O. niloticus. Conversely, tebuconazole exhibited significant and persistent effects on various biochemical parameters, including lactate, albumin, and total protein, as well as hematological parameters like hemoglobin and MCH. The use of lecithin and tebuconazole should only be limited to decoupled aquaponics.

• Klíčová slova
• Aquaponics, Clove oil, Fungicides, Lecithin, Nitrification, Tilapia, Toxicity,
• MeSH
• amoniové sloučeniny * MeSH
• cichlidy * metabolismus   MeSH
• dusík analýza   MeSH
• hřebíčkový olej MeSH
• lecitiny MeSH
• nitrifikace MeSH
• průmyslové fungicidy * toxicita   MeSH
• vodní hospodářství metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amoniové sloučeniny * MeSH
• dusík MeSH
• hřebíčkový olej MeSH
• lecitiny MeSH
• průmyslové fungicidy * MeSH

The influence of industrial (pharmaceutical and chemical) wastewater composition on membrane bioreactor (MBR) performance was investigated in a pilot-scale installation. The study focussed on nitrification performance, which was evaluated based on influent and effluent parameters as well as batch nitrification rate tests. The industrial wastewater was pumped into the MBR in a mixture with municipal wastewater at constant flow rate. The loading of the MBR with industrial wastewater was increased stepwise from 0 to 75% share in the mixed influent to study the adaptation of nitrifying bacteria. Stable nitrification performance was observed until the content of industrial wastewater in the influent reached 40%, with effluent values of around 0.56 mg L(-1) NH4-N and 98.3% ammonia removal. Breakdown of nitratation was observed at a 40% industrial wastewater dose and breakdown of nitritation at a 50% dose, respectively. However, after several months of adaptation, both processes recovered. No nitrification was observed when the industrial wastewater share exceeded 50%. Adaptation of nitrifying bacteria in the MBR was also confirmed by results of kinetic tests. The inhibition effect of the concentrated industrial wastewater to the MBR sludge decreased substantially after several months of exposure, while the inhibition of referential activated sludge remained constant.

• Klíčová slova
• ATU, AUR, Activated sludge, Adaptation, COD, EPS, F/M, HRT, IWW, Industrial wastewater, Inhibition, MLSS, MWCO, Membrane bioreactor, N(T), Nitrification, OUR, P(T), PES, PVDF, SMP, SRT, TMP, allylthiourea, ammonia uptake rate, chemical oxygen demand, extracellular polymeric substances, food to microorganisms ratio, hydraulic retention time, industrial wastewater, mixed liquor suspended solids, molecular weight cut-off, oxygen uptake rate, polyethersulfone, polyvinylidene fluoride, sludge retention time, soluble microbial products, total nitrogen, total phosphorus, transmembrane pressure,
• MeSH
• bioreaktory * MeSH
• čištění vody * MeSH
• dusík izolace a purifikace   MeSH
• filtrace MeSH
• membrány umělé * MeSH
• měření biologické spotřeby kyslíku MeSH
• nitrifikace * MeSH
• odpad tekutý - odstraňování MeSH
• odpadní voda MeSH
• odpadní vody chemie   MeSH
• permeabilita MeSH
• pilotní projekty MeSH
• průmyslový odpad analýza   MeSH
• velkoměsta MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• velkoměsta MeSH
• Názvy látek
• dusík MeSH
• membrány umělé * MeSH
• odpadní voda MeSH
• odpadní vody MeSH
• průmyslový odpad MeSH

Nitrite-oxidizing bacteria (NOB) catalyse the second nitrification step and are the main biological source of nitrate. The most diverse and widespread NOB genus is Nitrospira, which also contains complete ammonia oxidizers (comammox) that oxidize ammonia to nitrate. To date, little is known about the occurrence and biology of comammox and canonical nitrite oxidizing Nitrospira in extremely alkaline environments. Here, we studied the seasonal distribution and diversity, and the effect of short-term pH changes on comammox and canonical Nitrospira in sediments of two saline, highly alkaline lakes. We identified diverse canonical and comammox Nitrospira clade A-like phylotypes as the only detectable NOB during more than a year, suggesting their major importance for nitrification in these habitats. Gross nitrification rates measured in microcosm incubations were highest at pH 10 and considerably faster than reported for other natural, aquatic environments. Nitrification could be attributed to canonical and comammox Nitrospira and to Nitrososphaerales ammonia-oxidizing archaea. Furthermore, our data suggested that comammox Nitrospira contributed to ammonia oxidation at an extremely alkaline pH of 11. These results identify saline, highly alkaline lake sediments as environments of uniquely strong nitrification with novel comammox Nitrospira as key microbial players.

• MeSH
• amoniak MeSH
• Archaea genetika   MeSH
• Bacteria genetika   MeSH
• dusičnany MeSH
• dusitany * MeSH
• fylogeneze MeSH
• jezera * MeSH
• koncentrace vodíkových iontů MeSH
• nitrifikace MeSH
• oxidace-redukce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amoniak MeSH
• dusičnany MeSH
• dusitany * MeSH

• Klíčová slova
• NITRITES *, SOIL MICROBIOLOGY *,
• MeSH
• dusitany * MeSH
• nitrifikace * MeSH
• půda * MeSH
• půdní mikrobiologie * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dusitany * MeSH
• půda * MeSH

Nitrous oxide (N2O), is a potent greenhouse gas (GHG) that shares 7% of global warming around the world. Among different sources, agricultural systems account for approx. 60% of global anthropogenic N2O emissions. These N2O emissions are associated with the activity of nitrifiers and denitrifiers that contribute to >4 Tg (teragrams) N2O-N emission per year. Application of nitrogen (N) fertilizers and manures in agricultural fields plays an imperative role in this regard. On the other hand nitrification inhibitors are an effective approach to minimize N2O-N emissions from agricultural fields. Here we examined the effects of applying urea with a nitrification inhibitor (Ni) nitrapyrin and mulch (Mu) on urea transformation, nitrous oxide (N2O) emissions, grain yield and nitrogen (N) uptake efficiency. The treatments include a control (zero N), urea (U) applied at 200 kg N ha-1, U + Ni (Ni applied at 700 g ha-1), U+ Mu (Mu applied at 4 t ha-1) and U + Ni + Mu. The N2O emission factor (EF) was 66% and 75% when U and Mu were applied, respectively. Yield-scaled N2O emissions were lower in U and Mu by 45% and 55%, respectively. The Ni coupled with Mu enhanced urea-15N recovery by 58% and wheat grain yield by 23% and total N uptake by 30% compared with U alone. In conclusion, Ni usage is an effective strategy to mitigate N2O emissions under field conditions.

• Klíčová slova
• (15)N recovery, Mulch, Nitrification inhibitor, Nitrous oxide emission, Urea, Wheat crop,
• Publikační typ
• časopisecké články MeSH

The high input of nitrogen is often required in today's agriculture, especially for the most cultivated crops largely involved in human and animal nutrition, such as winter wheat. Nitrogen is a mobile nutrient in the soil, and the high doses of N are often associated with possible losses through volatilization or leaching. One of the possible options to increase nitrogen use efficiency is the application of fertilizers with inhibitors. The main objective of the presented three-year experiment established under the field conditions at the two experimental sites was to examine the effect of nitrogen-sulphur fertilizer (ammonium nitrate sulphate) with the inhibitors of nitrification (IN) (dicyandiamide and 1,2,4 triazole). In addition to the nitrogen content in two forms, this fertilizer also contains sulphur, which can possibly enhance the utilization of nitrogen due to their well-known synergy. The treatments included in the experiment were: 1. Unfertilized, 2. N technology 3. N + S technology and 4. N + S + IN. The total dose of applied N for every fertilized treatment was 159 kg/ha. Treatments 2 and 3 were fertilized with three split doses of N, treatment 4 was fertilized only two times due to the addition of IN (a higher dose of fertilizer in the second application). The results obtained from the three-year experiment showed a significantly higher yield of grain (8.18 t/ha) after the fertilization with N + S + IN in comparison with N + S (7.67 t/ha) and N (7.61 t/ha), which proved the positive effect of IN on nitrogen use efficiency during the vegetation. The differences between qualitative parameters of wheat grain (hectolitre weight, protein and gluten content) were evaluated as statistically insignificant for each fertilized treatment. This similar result is likely due to the IN application, which provided a continuous nitrogen supply during vegetation comparable to the three split nitrogen applications. Thus, our results showed, that the addition of IN to the higher dose of fertilizer applied earlier in the vegetation can provide comparable results in terms of quality to the technologies based on three split fertilizations. The three-year experiment established at two experimental sites has proved, that the application of ammonium sulphate nitrate fertilizers with IN in a higher dose is a better option to the commonly used nitrogen technology, which was also supported by the economic evaluation and the highest net profit.

• Klíčová slova
• Grain yield, Inhibitor of nitrification, Nitrogen, Sulphur, Winter wheat,
• Publikační typ
• časopisecké články MeSH

A soil naturally containing montmorillonite (M) was amended with 10% M and sequentially perfused with glyeme, with fresh glyeme being added every 16--17d after nitrification of the previously added glycine-nitrogen had reached a plateau. In some systems, the old perfusates were replaced each time with a fresh glycine solution; in others, the initial perfusate was not replaced but only adjusted each time to the original 200 ml volume and a comparable glycine concentration (140 micrograms NH2-N/ml). The incorporation of M enhanced the rates of heterotrophic degradation of glycine and subsequent autotrophic nitrification, but these stimulatory effects decreased with each successive perfusion. The reasons for these decreases are not known, but they did not appear to be related to inorganic nutrition, as perfusion with a mixed cation solution after five perfusion cycles did not significantly enhance nitrification in either the check or M-amended soils during three subsequent perfusions with glycine. The enhancement of nitrification by M appeared to be a result, in part, of the greater buffering capacity of the M-amended soil, as indicated by lesser reductions in the pH of perfusates from the M-amended soil, by titration curves of the soils, and by the greater and longer stimulation of nitrification in the check soil amended with 1% CaCO3, which had a greater buffering capacity than did M. The stimulation by CaCO3 may also have been partially the result of providing CO2 for the autotrophic nitrifyers. Significant concentrations of nitrite accumulated only in perfusates from soil amended with CaCO3. Air-drying and remoistening the soils enhanced nitrification of subsequently added glycine, especially in the check soil. The importance of pH-mediation, of the production of inhibitors, and/or of feed-back inhibition was indicated by the lower rate and extent of nitrification in systems wherein the perfusates were not replaced between successive additions of glycine. Although the results of these studies confirmed previous observations that M enhances the rate of nitrification in soil, the mechanisms responsible for this stimulation are still not known.

• MeSH
• bentonit farmakologie   MeSH
• biodegradace MeSH
• chemická stimulace MeSH
• dusičnany metabolismus   MeSH
• dusitany metabolismus   MeSH
• glycin farmakologie   MeSH
• kvartérní amoniové sloučeniny metabolismus   MeSH
• Nitrobacter metabolismus   MeSH
• půdní mikrobiologie * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bentonit MeSH
• dusičnany MeSH
• dusitany MeSH
• glycin MeSH
• kvartérní amoniové sloučeniny MeSH