scholarly journals Cyanobacterial growth and cyanophycin production with urea and ammonium as nitrogen source

2021 ◽  
Author(s):  
S. Canizales ◽  
M. Sliwszcinka ◽  
A. Russo ◽  
S. Bentvelzen ◽  
H. Temmink ◽  
...  
Keyword(s):  
Nitrogen Source ◽  
Synthetic Medium ◽  
N:P Ratio ◽  
Molar Ratio ◽  
P Limitation ◽  
Ammonium N ◽  
Microalgae Biomass ◽  
Nitrogen Concentrations ◽  
Nitrogen Phosphorus ◽  
Significant Growth Inhibition

AbstractSeveral technologies have aimed to recover nitrogen directly from urine. Nitrogen recovery in these technologies was limited by the mismatch of the nitrogen-phosphorus molar ratio (N:P) of urine, being 30–46:1, and that of the final product, e.g., 1:1 in struvite and 16–22:1 in microalgae biomass. Additionally, the high nitrogen concentrations found in urine can be inhibitive for growth of microorganisms. Cyanobacteria were expected to overcome phosphorus (P) limitation in urine given their ability to store an N-rich polymer called cyanophycin. In this study, it was found that the model cyanobacterium Synechocystis sp. PCC6803 did not experience significant growth inhibition when cultivated in synthetic medium with concentrations of 0.5 g ammonium-N L−1. In the case of urea, no inhibition was observed when having it as sole nitrogen source, but it resulted in chlorosis of the cultures when the process reached stationary phase. Synechocystis was successfully cultivated in a medium with 0.5 g ammonium-N L−1 and a N:P ratio of 276:1, showing the N:P flexibility of this biomass, reaching biomass N:P ratios up to 92:1. Phosphorus starvation resulted in cyanophycin accumulation up to 4%. Dilution of the culture in fresh medium with the addition of 118 mg N L−1 and 1.5 mg P L−1 (N:P of 174:1) resulted in a rapid and transient cyanophycin accumulation up to 11%, after which cyanophycin levels rapidly decreased to 3%.

scholarly journals Effects of serpentinite fertilizer on the chemical properties and enzyme activity of young spruce soils

2016 ◽  
Vol 30 (4) ◽  
pp. 401-414 ◽  
Author(s):  
Ewa Błońska ◽  
Kazimierz Januszek ◽  
Stanisław Małek ◽  
Tomasz Wanic
Keyword(s):  
Enzyme Activity ◽  
Chemical Properties ◽  
Molar Ratio ◽  
Tree Roots ◽  
Forest Zone ◽  
Negative Effect ◽  
Phosphorus And Potassium ◽  
One Year ◽  
Nitrogen Phosphorus ◽  
Experimental Plots

AbstractThe experimental plots used in the study were located in the middle forest zone (elevation: 900-950 m a.s.l.) on two nappes of the flysch Carpathians in southern Poland. The aim of this study was to assess the effects of serpentinite in combination with nitrogen, phosphorus, and potassium fertilizers on selected chemical properties of the soil and activity of dehydrogenase and urease in the studied soils. All fertilizer treatments significantly enriched the tested soils in magnesium. The use of serpentinite as a fertilizer reduced the molar ratio of exchangeable calcium to magnesium, which facilitated the uptake of magnesium by tree roots due to competition between calcium and magnesium. After one year of fertilization on the Wisła experimental plot, the pH of the Ofh horizon increased, while the pH of the mineral horizons significantly decreased. Enrichment of serpentinite with nitrogen, phosphorus, and potassium fertilizers stimulated the dehydrogenase activity in the studied organic horizon. The lack of a negative effect of the serpentinite fertilizer on enzyme activity in the spruce stand soil showed that the concentrations of the heavy metals added to the soil were not high enough to be toxic and indicated the feasibility of using this fertilizer in forestry.

THE EFFECT OF CERTAIN ELEMENTS, WITH EMPHASIS ON NITROGEN, ON THE PRODUCTION OF PERITHECIA OF VENTURIA INAEQUALIS (CKE.) WINT.

1961 ◽  
Vol 39 (4) ◽  
pp. 731-738 ◽  
Author(s):  
R. G. Ross
Keyword(s):  
Venturia Inaequalis ◽  
Synthetic Medium ◽  
Low Concentrations ◽  
Nitrate Salts ◽  
Nitrogen Concentrations ◽  
High Concentrations

Various elements were tested for their effect on the formation of perithecia of Venturia inaequalis. Apart from nitrogen the elements tested had little effect on the formation of perithecia except at relatively high concentrations. Perithecia did not form in media containing low concentrations of nitrogen and this was influenced by the source of nitrogen and by the cation present in nitrate salts. Perithecial initials developed in higher nitrogen concentrations than perithecia. Nitrogen added 9 weeks after mating of two lines of the fungus prevented the formation of perithecia.Results were difficult to reproduce in a potato-dextrose apple leaf decoction medium but reproducible results were obtained in a synthetic medium.

Ruminal peptide and ammonia nitrogen concentrations in steers fed diets with different concentrate to lucerne hay ratios

2007 ◽  
Vol 2007 ◽  
pp. 214-214
Author(s):  
Alireza Vakili ◽  
Mohsen Danesh Mesgaran ◽  
Reza Valizadeh ◽  
Alireza Heravi Moussavi ◽  
Mohammad Reza Nassiry ◽  
...  
Keyword(s):  
Nitrogen Source ◽  
Present Experiment ◽  
Crude Protein ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Ammonia Production ◽  
Ruminal Ph ◽  
Ruminal Microorganisms ◽  
Dietary Crude Protein ◽  
Nitrogen Concentrations

In ruminants, as much as 50% of the dietary crude protein can be converted to ammonia by ruminal microorganisms. A part of ammonia can be utilized as a bacterial nitrogen source; however, rates of ammonia production often exceed rates of ammonia utilization. Peptides are intermediates in the conversion of ingested protein to ammonia in the rumen and their accumulation depends upon the nature of diet (Mesgaran & Parker, 1995). The objective of the present experiment was to investigate the effect of diets differing in concentrate: lucerne hay ratios on the ruminal pH, ammonia-nitrogen concentration and ruminal peptide nitrogen concentration in Holstein steers.

Trophic state evolution in a subtropical reservoir over 34 years in response to different management procedures

2011 ◽  
Vol 64 (12) ◽  
pp. 2338-2344 ◽  
Author(s):  
D. G. F. Cunha ◽  
D. Grull ◽  
M. Damato ◽  
J. R. C. Blum ◽  
J. E. I. Lutti ◽  
...  
Keyword(s):  
Flood Control ◽  
Trophic State ◽  
Phase 1 ◽  
Nutrient Inputs ◽  
Chl A ◽  
P Limitation ◽  
Tietê River ◽  
Management Procedures ◽  
Special Cases ◽  
Nitrogen Concentrations

Despite their importance for water management, long-term studies on trophic state are relatively scarce in subtropical reservoirs. We analyzed total phosphorus (TP), total nitrogen (TN) and chlorophyll a (Chl a) concentrations in the Billings Reservoir (Brazil) over time: Phase 1 (1977–1992, Tietê River water was pumped to Billings to increase energy generation, 100 m3 s−1); Phase 2 (1992–2007, Tietê water was conveyed to Billings only in special cases for flood avoidance, 8 m3 s−1); and Phase 3 (2007–2010, besides flood control, Billings received Tietê water treated by an in situ flotation system, 13 m3 s−1). We compared our results with data from 12 reservoirs to evaluate current (2005–2009) enrichment conditions. Phosphorus and nitrogen concentrations decreased (p < 0.05, MANOVA) from Phase 1 to 2 and were stable thereafter. TN/TP ratios increment (1977–2010) indicated shift from N- to P-limitation in the reservoir, affecting the phytoplankton. Nutrient levels in Billings are currently between the expected concentrations in mesotrophic and eutrophic reservoirs (0.03 mg L−1 < TP < 0.42 mg L−1, 0.8 mg L−1 < TN < 7.6 mg L−1) and Chl a concentrations exceeded 34 μg L−1, median for the eutrophic waterbodies from the dataset. Although water quality in Billings has improved, nutrient inputs from Tietê River pumping episodes, diffuse and internal sources are still favoring biomass accrual and compromising water uses.

Effects of zooplankton and nutrients on phytoplankton: an experimental analysis in a eutrophic tropical reservoir

2017 ◽  
Vol 68 (6) ◽  
pp. 1061 ◽  
Author(s):  
Juliana dos Santos Severiano ◽  
Viviane Lúcia dos Santos Almeida-Melo ◽  
Enaide Marinho de Melo-Magalhães ◽  
Maria do Carmo Bittencourt-Oliveira ◽  
Ariadne do Nascimento Moura
Keyword(s):  
Experimental Analysis ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
N:P Ratio ◽  
Molar Ratio ◽  
Zooplankton Species ◽  
Tropical Reservoir ◽  
Total Phytoplankton Biomass ◽  
Taxonomic Class ◽  
Total Phytoplankton

Experiments were conducted to evaluate the N:P ratio, as well as the effects of the interaction between this ratio and zooplankton, on phytoplankton in a tropical reservoir. Three experiments were performed in the presence (+Z) or absence (–Z) of zooplankton and the addition of N and P in different ratios (N:P molar ratio of 5, 16 and 60).In Experiment I, the total phytoplankton biomass and biomass by taxonomic class and species of the N:P 16–Z treatment did not differ significantly from that of the control, whereas for N:P 16+Z, there was a reduction in total phytoplankton. In Experiment II, there was a significant increase in Bacillariophyceae and the biomass of two species in the N:P 60–Z treatment. For the N:P 60+Z treatment, a significant reduction was observed in the total phytoplankton biomass and the biomass of three phytoplankton classes and three species. In Experiment III, there was an increase in the biomass of Dinophyceae with the N:P 5–Z treatment. In the N:P 5+Z treatment, there was a significant reduction in total phytoplankton biomass and the biomass of the phytoplankton class and five species. The findings of the present study reveal that zooplankton species native to a tropical reservoir can change the structure of the phytoplankton community and the response of these organisms to variations in nutrients.

Studies of the hydrobiology of a tropical lake in north-western Queensland. III. Growth, chemical composition and potential for harvesting of the aquatic vegetation

1984 ◽  
Vol 35 (5) ◽  
pp. 525 ◽  
Author(s):  
CM Finlayson ◽  
TP Farrell ◽  
DJ Griffiths
Keyword(s):  
Aquatic Plants ◽  
Aquatic Vegetation ◽  
Hydrilla Verticillata ◽  
Limiting Factor ◽  
Potamogeton Crispus ◽  
Low Light ◽  
Mean Values ◽  
Nitrogen Concentrations ◽  
North Western ◽  
Nitrogen Phosphorus

The biomass of aquatic plant species and the standing crop of submerged species were estimated in Lake Moondarra from 1977 to 1979. In July 1978, the biomass of Salvinia molesta exceeded 53 000 t fresh weight, with a density of 167 t ha-1 (0.81 kg dry wt m-2). Hydrilla verticillata reached a maximum density of almost 3 kg dry wt m-2 and Potamogeton crispus more than double that density. Photosynthetic activity of a range of species was high, and was still detectable at water depths allowing only very low light penetration. Organic nitrogen concentrations were high (0.91-4.37% dry wt), and phosphorus (0.07-0.47% dry wt) appeared to be a limiting factor for growth of the aquatic plants. Heavy metal concentrations varied with species, location and season but, although generally higher than world-wide 'mean' values (48 �g g-1 copper, 11 �g g-1 lead, 14.3 �g g-1 zinc), were significantly less than those of aquatic macrophytes in heavily polluted environments. H. verticillata was more efficient than S. molesta in removal of nitrogen, phosphorus and zinc, whereas for copper and lead the reverse was true. The potential for using this property of the aquatic plants and subsequent harvesting in order to remove nutrients and metals from the lake is also discussed.

Relationship Between N2-Fixation and Heterocyst Abundance and its Relevance to the Nitrogen Budget of Lake 227

1994 ◽  
Vol 51 (10) ◽  
pp. 2254-2266 ◽  
Author(s):  
D. L. Findlay ◽  
R. E. Hecky ◽  
L. L. Hendzel ◽  
M. P. Stainton ◽  
G. W. Regehr
Keyword(s):  
N:P Ratio ◽  
Molar Ratio ◽  
External Loading ◽  
N Fixation ◽  
Fixation Rate ◽  
Loading Rates ◽  
Relative Contribution ◽  
Cyanobacteria Blooms ◽  
N Loading ◽  
Low Nitrogen

A significant relationship between seasonal N2-fixation rate and heterocyst abundance has been found in Lake 227 and can be modelled to estimate areal rates of N2-fixation based on the known historical phytoplankton records. Experimental imposition of low nitrogen (N): phosphorus (P) loading ratios stimulated N,-fixation. The N:P molar ratio of the internal pool of nutrients oscillates around a mean of 30:1, despite experimental loading ratios that vary from 13:1 to 0. Maintenance of this internal nutrient mass ratio requires preferential regeneration of N through time at all loading rates. Heterocystous, cyanobacteria blooms are most predictable during imposition of a very low external loading N:P ratio and high P loading relative to natural sources. Knowledge of the internal loading N:P ratio and relative contribution of internal and external loadings are required for predicting blooms at intermediate external N:P loading rates. The internal N:P ratio has fluctuated within narrow limits over 25 yr of nearly constant P loading because of adjustments in N2-fixation, N sedimentation, and denitrification, which have counterbalanced changing experimental N loading regimes.

scholarly journals Mapping the Forage Nitrogen-Phosphorus Ratio Based on Sentinel-2 MSI Data and a Random Forest Algorithm in an Alpine Grassland Ecosystem of the Tibetan Plateau

2020 ◽  
Vol 12 (18) ◽  
pp. 2929
Author(s):  
Jinlong Gao ◽  
Jie Liu ◽  
Tiangang Liang ◽  
Mengjing Hou ◽  
Jing Ge ◽  
...  
Keyword(s):  
Random Forest ◽  
Nutrient Deficiency ◽  
Growth Period ◽  
N:P Ratio ◽  
Alpine Grassland ◽  
Estimation Accuracy ◽  
Ecological Indicator ◽  
The Tibetan Plateau ◽  
Nitrogen Phosphorus ◽  
Sentinel 2

Nondestructive and accurate estimating of the forage nitrogen–phosphorus (N:P) ratio is conducive to the real-time diagnosis of nutrient limitation and the formulation of a management scheme during the growth and development of forage. New-generation high-resolution remote sensors equipped with strategic red-edge wavebands offer opportunities and challenges for estimating and mapping forage N:P ratio in support of the sustainable utilization of alpine grassland resources. This study aims to detect the forage N:P ratio as an ecological indicator of grassland nutrient content by employing Sentinel-2 multispectral instrument (MSI) data and a random forest (RF) algorithm. The results showed that the estimation accuracy (R2) of the forage N:P ratio model established by combining the optimized spectral bands and vegetation indices (VIs) is 0.49 and 0.59 in the vigorous growth period (July) and the senescing period (November) of forage, respectively. Moreover, Sentinel-2 MSI B9 and B12 bands contributed greatly to the estimation of the forage N:P ratio, and the VIs (RECI2) constructed by B5 and B8A bands performed well in the estimation of the forage N:P ratio. Overall, it is promising to map the spatial distribution of the forage N:P ratio in alpine grassland using Sentinel-2 MSI data at regional scales. This study will be potentially beneficial in implementing precise positioning of vegetation nutrient deficiency and scientific fertilization management of grassland.

The response of juvenile and small adult western juniper (Juniperus occidentalis) to nitrate and ammonium fertilization

1991 ◽  
Vol 69 (11) ◽  
pp. 2344-2352 ◽  
Author(s):  
P. M. Miller ◽  
L. E. Eddleman ◽  
J. M. Miller
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Assimilation ◽  
Negative Effects ◽  
Foliar Nitrogen ◽  
Juniperus Occidentalis ◽  
Nitrate N ◽  
Ammonium N ◽  
Nitrogen Concentrations ◽  
Use Efficiency ◽  
N Treatment

Effects of nitrate-N and ammonium-N fertilization on foliar nitrogen concentrations, carbon dioxide assimilation, leaf conductance, transpiration, intercellular carbon dioxide, xylem pressure potentials, specific leaf mass, and growth were measured on naturally established juvenile and small adult Juniperus occidentalis growing in central Oregon where ammonium-N was the dominant form of soil nitrogen throughout the summer. Fertilization with both forms of nitrogen increased foliar nitrogen concentrations in juveniles and small adults in May; concentrations in small adult foliage from the nitrate-N treatment were still higher than controls in September. Both forms of nitrogen reduced carbon dioxide assimilation and potential photosynthetic nitrogen-use efficiency. The negative relationship between nitrogen addition and carbon dioxide assimilation was more apparent in juveniles than in small adults; negative effects were more pronounced in the ammonium-N treatment than in the nitrate-N treatment. Leaf conductance and transpiration were also reduced, but reductions of water loss were greater than were negative effects of fertilization on carbon gain; thus water-use efficiency of juvenile and small adults increased in May and July. The depression in gas exchange processes was detectable for a longer period during the summer in juveniles than in small adult J. occidentalis. Branchlet elongation of juvenile and small adult J. occidentalis was increased with nitrate-N and ammonium-N addition, but variability reduced significance levels. Juniperus occidentalis appears to be adapted to utilize low, ambient levels of soil nitrate at the research site and did not preferentially utilize ammonium. Key words: gas exchange, water relations, foliar nitrogen, growth.

scholarly journals KH2PO4 crystallisation from potassium chloride and ammonium dihydrogen phosphate

2016 ◽  
Vol 18 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Kristina Jančaitienė ◽  
Rasa Šlinkšienė
Keyword(s):  
Aqueous Solutions ◽  
Potassium Chloride ◽  
Solid Phase ◽  
Potassium Dihydrogen Phosphate ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Potassium Dihydrogen ◽  
Increasing Temperature ◽  
Nitrogen Phosphorus

Abstract Seeking to obtain bulk (NPK – nitrogen, phosphorus, potassium), chlorine-free fertilizers, the influence of interaction between potassium chloride and ammonium dihydrogen phosphate in aqueous solutions at temperature of 20, 40, 60 and 80°C has been investigated. Components of the solid phase have been identified by methods of chemical and instrumental analysis: radiography (X – ray), infra – red molecular absorption spectroscopy (IR) and scanning electron microscopy (SEM). It has been observed that the largest amount of solid state potassium dihydrogen phosphate was obtained at 60–80°C, when the potassium chloride and ammonium dihydrogen phosphate molar ratio is equal 0.8:0.2. Changing the molar ratio of 0.5:0.5 to 0.8:0.2, and with increasing temperature, various shaped crystals have developed in the remaining aqueous solutions with a morphology shifting from sharp needles to tetragonal prism.

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