Ammonia In Medium Research Articles

Rapid total sialic acid monitoring during cell culture process using a machine learning model based soft sensor.

Total sialic acid content (TSA) in biotherapeutic proteins is often a critical quality attribute as it impacts the drug efficacy. Traditional wet chemical assays to quantify TSA in biotherapeutic proteins during cell culture typically takes several hours or longer due to the complexity of the assay which involves isolation of sialic acid from the protein of interest, followed by sample preparation and chromatographic based separation for analysis. Here, we developed a machine learning model-based technology to rapidly predict TSA during cell culture by using typically measured process parameters. The technology features a user interface, where the users only have to upload cell culture process parameters as input variables and TSA values are instantly displayed on a dashboard platform based on the model predictions. In this study, multiple machine learning algorithms were assessed on our dataset, with the Random Forest model being identified as the most promising model. Feature importance analysis from the Random Forest model revealed that attributes like viable cell density (VCD), glutamate, ammonium, phosphate, and basal medium type are critical for predictions. Notably, while the model demonstrated strong predictability by Day 14 of observation, challenges remain in forecasting TSA values at the edges of the calibration range. This research not only emphasizes the transformative power of machine learning and soft sensors in bioprocessing but also introduces a rapid and efficient tool for sialic acid prediction, signaling significant advancements in bioprocessing. Future endeavors may focus on data augmentation to further enhance model precision and exploration of process control capabilities.

Processes of Ablation and Structures Growth under the Action of Femtosecond Laser Pulses on the Gallium Surface in an Ammonia Medium

Processes of Ablation and Structures Growth under the Action of Femtosecond Laser Pulses on the Gallium Surface in an Ammonia Medium

Synergistic antifungal effects of the preservative ammonium propionate and medium chain fatty acids against dormant and germinating conidia, germ tubes and hyphae of Aspergillus chevalieri, a feed spoilage fungus

In feed, propionic acid is the weak organic acid of choice to prevent growth of spoilage fungi. For safe and easy industrial handling this antifungal agent is applied in the presence of neutralizing ammonium, which however has the disadvantage to negatively affect the efficacy of fungus-inhibiting properties of the formulation. In the present study we investigated the impact of medium chain fatty acids (MCFA) on the antifungal efficacy of an ammonium propionate formulation on dormant- and germinating conidia as well as germ tubes and hyphae of Aspergillus chevalieri, a xerophilic fungus predominant on moulded feed. Dormant conidia were not affected by 32 mM of ammonium propionate after a 28 h-treatment in demi water. Similar results were obtained with solely 0.52 mM MCFA. However, the combination of both components nearly eradicated formation of colonies from these conidia and was accompanied by distortion of the cellular structure as was visible with light- and transmission electron microscopy. Germination of conidia, characterised by swelling and germ tube formation, was significantly decreased in the presence of 16 mM ammonium propionate and 0.26 mM MCFA, while the latter component itself did not significantly decrease germination. We conclude that a combination of ammonium propionate and MCFA had a synergistic antifungal effect on dormant and germinating conidia.When the combination of ammonium propionate and MCFA was tested on hyphae for 30 min, we observed that cell death was significantly increased in comparison to components alone. Treatment of the hyphae with 16 mM of ammonium propionate caused aberrant mitochondria, as evidenced by irregularly shaped and enlarged mitochondria that contained electron-dense inclusions as observed by transmission electron microscopy. When the combination of ammonium propionate and MCFA was applied against the hyphae, more severe cell damage was observed, with signs of autophagy. Summarised, our results demonstrate synergistic antifungal effects of ammonium propionate and medium chain fatty acids on fungal survival structures, during their germination and after a short (sudden) treatment of growing cells. This is of potential importance for several areas of feed and food storage and shelf-life.

Acid and ammonia leaching of secondary copper sulfides

The study focuses on understanding the efficiency and kinetics of copper recovery from secondary sulphide ores, which are increasingly becoming a significant source of copper. An experimental investigation was undertaken to assess the leaching behaviour of secondary copper sulphides in acid and ammonia media. The test work consisted of ore sample characterisation, including physico-mechanical properties determination, chemical assay, whole rock analysis, mineralogy, and copper distributions, followed by acid consumption tests, agglomeration, and agitation leach tests. Leaching tests were conducted in a lab-scale agitated reactor using 100 g of the ore sample, 0.3 l of leach solution, а stirring rate of 420 rpm and a leach time of up to 200 hours. The effect of the reaction time and oxidant (Fe3+, NO+) concentration on the copper recovery was evaluated. The maximum copper extraction was obtained in the test performed using acid media with the addition of NO+ as an oxidant. Further, a potential hydrometallurgical process option for recovering copper from secondary sulphide sources is proposed.

Exploring the Efficacy of Bacillus oceanisediminis Ba9 from Asian Seabass Cage Sediment in Saline Wastewater Treatment

Preventing toxicity in aquaculture systems from ammonia and nitrite is important. This study isolated the salt-tolerant Bacillus sp. strain Ba9 from bottom sediment under an Asian Seabass (Lates calcarifer) cage cultivating at Koh Yor, Songkhla, Thailand. Morphological characteristics showed that strain Ba9 was rod-shaped, endospore-forming, and Gram-positive. Strain Ba9 grew well at a salinity of 1.5 to 4.0% NaCl. The catalase test of the isolate was positive, while the oxidase test was negative. Based on 16S rRNA gene sequencing data and phylogenetic tree analysis, strain Ba9 was identified as B. oceanisediminis with 97% similarity (strain HQB337T). The result showed that the ammonium removal efficiency of Ba9 in a high ammonium medium was 64.24%. The nitrite and nitrate production were 0.10% and 0.08%, respectively. Consequently, sucrose had been the optimal carbon source for Ba9, which showed ammonium removal was 61.05%. Ammonium sulfate is the most suitable for ammonium oxidation, with 50.53% for the nitrogen source. The optimal C/N ratio of strain Ba9 was 8, with 71.15% ammonia removal. For wastewater improvement, strain Ba9 was inoculated into artificial wastewater for 14 days. The result showed that the ammonium removal efficiency of Ba9 was 96.87%. In addition, the biochemical oxygen demand (BOD) removal efficiency of Ba9 was 90.86%. From this result, the salt-tolerant B. oceanisediminis Ba9 has a high potential as a microbial product for water quality management in marine aquaculture.

Closed-loop process for Zn and Cu selective recovery from MSWI bottom ash fine fraction

In 2019, 224 Mt of Municipal Solid Wastes (MSW) were produced in Europe. A significant proportion of this MSW is treated by incineration producing each year 20 Mt of Municipal Solid Waste Incineration (MSWI) Bottom Ashes (BA). While the coarsest fraction (>2mm) can be reemployed in construction field, this is not the case for the finest fraction <2 mm (30% wt.) which is intended to be landfilled. The challenges of the treatment of this solid residue are multiple. The metals of interest are dispersed within this complex matrix and the gangue is composed by a large proportion of carbonate based minerals which reduces the choice of possible leaching agents. Moreover, the large amounts of iron and aluminum imply to choose a highly selective recovery method and the economic constrains steer the process towards low-cost technologies. The aim of this work is to study the feasibility of a selective copper and zinc recovery, whose contents in the bottom ash fine fraction are comparable to low-grade ores. A four-step process was designed consisting of a flushing, a leaching, a precipitation and an electrowinning. A selective leaching step using ammonia-ammonium chloride solution was carried out to avoid an iron co-leaching. After the leaching step, the precipitation of zinc was achieved by addition of aluminum nitrate followed by an electrodeposition of copper from ammonia medium. Up to 70% of Cu and Zn could be recovered with minimal modifications of the leachate composition allowing thus its reuse. The developed process enables the recovery of metallic copper and zinc in a spinel form from a waste originally intended for landfilling.

Spectrophotometric Investigation of the Reaction of Cu(II) Ions with N-Benzoyl-N'-(phenylsulphonyl)hydrazine in Ammonia Media

Spectrophotometric Investigation of the Reaction of Cu(II) Ions with N-Benzoyl-N'-(phenylsulphonyl)hydrazine in Ammonia Media

Pervaporation and Gas Separation Properties of High-Molecular Ladder-like Polyphenylsilsesquioxanes.

This paper presents the results of studies on the pervaporation properties (for benzene/hexane mixtures) and gas permeability (for He, H2, N2, O2, CO2, CH4, C2H6, and C4H10) of ladder-like polyphenylsesquioxanes (L-PPSQ) with improved physical and chemical properties. These polymers were obtained by condensation of cis-tetraphenylcyclotetrasiloxanetetraol in ammonia medium. The structure of L-PPSQ was fully confirmed by a combination of physicochemical analysis methods: 1H, 29Si NMR, IR spectroscopy, HPLC, powder XRD, and viscometry in solution. For the first time, a high molecular weight of the polymer (Mn = 238 kDa, Mw = 540 kDa) was achieved, which determines its improved mechanical properties and high potential for use in membrane separation. Using TGA and mechanical analysis methods, it was found that this polymer has high thermal (Td5% = 537 °C) and thermal-oxidative stability (Td5% = 587 °C) and good mechanical properties (Young's module (E) = 1700 MPa, ultimate tensile stress (σ) = 44 MPa, elongation at break (ε) = 6%), which is important for making membranes workable under various conditions. The polymer showed a high separation factor for a mixture of 10% wt. benzene in n-hexane (126) at a benzene flow of 33 g/(m2h).

α-Ketoglutarate stimulates cell growth through the improvement of glucose and glutamine metabolism in C2C12 cell culture.

Cellular adaptation to physical training and energy metabolism play an important role during physical exercise. This study sought to investigate the effects of α-KG on cell growth and energy metabolism in C2C12 cell culture. C2C12 cells were cultured in media pretreated without (control) or with α-KG at different concentrations, and cells and media were harvested every 24 h for 8 days. From cell counts, specific cell growth rate (SGR) and doubling time were calculated. The content of glucose, glutamine, lactate, and ammonia in media was determined, and the specific consumption rate (SCR) or production rate (SPR) was calculated. Additionally, cell colony-forming efficiency (CFE) was determined. The control cells showed a CFE at 50%, a typical cell growth curve in the first 5 days with a mean SGR at 0.86/day, and a mean cell count doubling time at 19.4 h. In the group with α-KG at 100 mM, the cells underwent rapid cell death, and thus no further analysis was made. The treatment with α-KG at lower concentrations (0.1 mM and 1.0 mM) led to a higher CFE at 68 and 55%, respectively, whereas those in groups with higher α-KG concentration decreased (10 and 6% for 20 mM and 30 mM α-KG, respectively). The mean SGR was 0.95/day, 0.94/day, 0.77/day, 0.71/day, and 0.65/day for groups treated with α-KG at 0.1, 1.0, 10.0, 20.0, and 30.0 mM, respectively, and the corresponding cell count doubling time was 17.6, 17.8, 20.9, 24.6, and 24.7 h, respectively. In comparison with that of the control group, the mean glucose SCR decreased in all the groups treated with α-KG, while the mean glutamine SCR remained unchanged; the mean lactate SPR increased in the groups treated with α-KG ≥ 20.0 mM. Finally, the mean SPR of ammonia was lower in all α-KG groups than that in the control. The treatment with α-KG at lower concentrations increased cell growth whereas at higher concentrations decreased cell growth, and α-KG reduced glucose consumption and ammonia production. Therefore, α-KG stimulates cell growth in a dose-dependent manner, which is likely through the improvement of glucose and glutamine metabolism in a C2C12 culture setting.

Synthesis of Hydrophobic Nanosized Silicon Dioxide with a Spherical Particle Shape and Its Application in Fire-Extinguishing Powder Compositions Based on Struvite.

Textural and morphological features of hydrophobic silicon dioxide, obtained by the hydrolysis of tetraethoxysilane in an ammonia medium followed by modification of a spherical SiO2 particles surface with a hydrophobic polymethylhydrosiloxane, were studied in this work. The size of silicon dioxide particles was controlled during preparation based on the Stöber process by variation of the amount of water (mol) in relation to other components. The ratio of components, synthesis time and amount of the hydrophobizing agent were determined to obtain superhydrophobic monodisperse silicon dioxide with a spherical particle size of 50-400 nm and a contact angle of more than 150°. In the case of the struvite example, it was demonstrated that the application of spherical- shaped hydrophobic silicon dioxide particles in powder compounds significantly improves the flowability of crystalline hydrates. The functional additive based on the developed silicon dioxide particles makes it possible to implement the use of crystalline hydrates in fire-extinguishing powders, preventing agglomeration and caking processes. The high fire-extinguishing efficiency of the powder composition based on struvite and the developed functional additive has been proven by using thermal analysis methods (TGA/DSC).

Intensified grinding of metal shavings in ammonia medium

Intensified grinding of metal shavings in ammonia medium

Synthetic Conditions for Obtaining Different Types of Amine-Holding Silica Particles and Their Sorption Behavior

The Stöber version of a sol-gel method of co-condensation of two alkoxysilanes (structuring tetraethoxysilane (TEOS) and functionalising N-containing silane) in an ammonia medium was used for the one-pot synthesis of spherical silica particles with ≡Si(CH2)3NH2, ≡Si(CH2)3NH(CH2)2NH2, and ≡[Si(CH2)3NH]2 functional groups with available groups content of 1.3–2.3 mmol/g. The materials were researched by a range of methods, including SEM, TEM, IR spectroscopy, 13C, and 29Si solid-state NMR spectroscopy, acid-base titration, and thermal analysis to identify the peculiarities of the morphology, functional groups content, composition, and thermal resistance of the surface layers in the synthesised samples. The type of N-containing silane was shown to affect the structure and properties of the synthesised spherical particles. The silane with the simplest, 3-aminopropyl, functional group caused the formation of nonporous material composed of large 600–800 nm spherical microparticles. Meanwhile, the complication of functional groups enhanced the emergence of small 15 nm primary particles and the origination of porosity, generated by the slits between particles and particle agglomerates. Thereafter, the sorption properties of the synthesised hybrid materials for nickel(II) and copper(II)ions, and bovine serum albumin (BSA) were also found to be dependent on the structure of the materials and the type of incorporated functional group. The maximal static sorption capacity values towards the targeted adsorbates were shown by the samples with 3-aminopropyl groups (1.27 mmol Ni/g), diamine groups (1.09 mmol Cu/g), and secondary amine groups (204.6 mg BSA/g). The conducted research opens up the prospects of directed one-pot synthesis of amino-functionalised hybrid organosilica materials for different applications.

Insitu electrochemical impedance spectroscopy of PT-7 M and Fe-Ni-Cr alloys in chloride containing ammonia medium at high temperatures

Corrosion of Titanium-based PT-7 M and Fe-Ni-Cr-alloy was investigated in chloride-containing ammonia at 288 °C at pH288 °C7.23 and pH288 °C7.75. Oxide on Fe-Ni-Cr-alloy was compact compared to PT-7 M. EIS at 288 °C indicated lower metal loss for Fe-Ni-Cr -alloy. At lower pH, Fe-Ni-Cr exhibited an incubation period that is attributed to the adsorption of Cr-species. At lower pH, the metal loss was linear for PT-7 M, but repassivation occurred at higher pH. Pitting was not observed and the point defect-densities decreased at higher pH for both supporting a lower metal loss. Corrosion resistance of Fe-Ni-Cr-alloy matched that of the PT-7 M under the given conditions.

Processes of ablation and structures growth under the action of femtosecond laser pulses on the gallium surface in an ammonia medium

In this paper, we present the results of processing metallic gallium in an ammonia vapor medium at 2 bar pressure by femtosecond laser pulses. The influence of the ammonia concentration and the mode of laser beam scanning on the result of laser action is considered. It has been established that an increase in the concentration of ammonia vapor and a change in the scanning regime lead to a radical change in the laser ablation process. A decrease in the scanning speed leads to the cessation of the ablation process and the development of the nitridation process of the gallium surface, accompanied by the formation of columnar structures up to 12 mm long and about 100 μm in diameter. The synthesized nanoparticles and structures were studied using scanning electron microscopy, Raman spectroscopy, and X-ray analysis. Keywords: laser ablation, gallium nitride, gallium nitride nanoparticles manufacturing, ablative synthesis of gallium nitride nanoparticles.

Разработка спектрофотометрической методики определения ионов меди (II) с N-бензилоил-N'-(фенилсульфонил)гидразином

The results of studying the processes of complex formation of N-benzyloyl-N'-(phenylsulfonyl)hydrazine (BPSH) with Cu(II) ions in ammonia media are presented. The complex formation reaction was studied by spectrophotometric method. The maximum light absorption of the studied complex compound was determined. The optimal conditions for the complex formation of BFSH with Cu(II) ions were studied: the time for the development of the color of the complex; pH range of complex formation, amount of photometric reagent. The optimal ratios [Cu(II)]:[BFSH]=2:1 and 1:1 were determined by the saturation method. Under optimal conditions, a calibration curve was constructed for the determination of Cu(II) ions with BFSH in an ammonia medium. Methods of mathematical statistics determined the convergence and correctness of the spectrophotometric method of determination. Approbation of the technique was carried out on the product of flotation enrichment of sulfide copper-nickel ore of the Murmansk deposit.

Recovery of vanadium and nickel from spent-residue oil hydrotreating catalyst by direct acid leaching-solvent extraction

A process for the selective extraction and separation of vanadium and nickel from spent-residue oil hydrotreating catalysts by a direct acid leaching−solvent extraction method was studied. The extraction and separation of vanadium(IV) and nickel(II) are divided into two stages: acid coleaching of vanadium and nickel and solvent extraction. In the acid coleaching stage, the leaching ratios of vanadium and nickel reach 88.07% and 75.58%, respectively, which can realize highly effective coleaching. In the solvent extraction stage, countercurrent experiments show that the extraction ratio of vanadium can reach 99.21% after a three-stage extraction with P204 as the high-efficiency extractant of vanadium in the acidic environment, while nickel and iron are not extracted. After the anti-extraction solution is pretreated by aluminum precipitation, the extraction ratio of nickel reaches 99.79% after a three-stage extraction with LIX84-I as a high-efficiency extractant of nickel in ammonia medium. A process flow for the recovery of vanadium and nickel is proposed, which not only can realize the separation and recovery of vanadium and nickel but also can realize the recycling of reagents.

Изучение реакции ионов Cu(II) с N-(бензоил)-N'-(фенилсульфонил)гидразином в аммиачных средах спектрофотометрическим методом

The reaction of complexation of N-(benzoyl)-N'-(phenylsulfonyl)hydrazine with Cu(II) ions in an ammonia medium has been studied. The absorption spectra of the reagent and its complex with Cu(II) ions have been recorded and analyzed. The optimal conditions for the formation of the complex compound were found: the pH range of complex formation; optimal time for color development; amount of photometric reagent. Under optimal conditions for the complex formation of BPSH with Cu(II) ions, a calibration graph was constructed. The Bouguer-Lambert-Beer law is fulfilled in the range from 0,5 to 1,75 mg Cu(II) in 25 ml of solution. The true (19389) and apparent (4708) molar light absorption coefficients were calculated. The methods of saturation, equilibrium shift, curve intersection, isomolar series, and conductometric titration were used to determine the molar ratios in a solution of a complex compound – [Сu(II)]:[BFSH] = 1:1 and 1:2. According to the Babko method, the conditional stability constant of the complex was calculated – 2,45∙1013. The convergence and correctness of the spectrophotometric technique were determined by the method of mathematical statistics.

Increased ammonium in culture medium may promote cellular apoptosis and negatively affect pluripotency of human blastocysts.

To determine the association between ammonium concentration in culture medium and blastocyst development and to assess the influence of increased ammonium concentration on the expression of Bax, Bcl-2 and Oct4. A total of 254 cleavage-stage embryos were individually cultured in 30μL G2-plus medium on Day 3, and then culture media samples were collected on Day 5 for ammonium concentration determination immediately after evaluating the embryos morphology. Poor-quality blastocysts (combined score of CC) were used for gene expression analysis. The blastocyst formation rate, good-quality blastocyst rate and relative expression levels of Bax, Bcl-2 and Oct4 were analyzed. Based on receiver operating characteristic curve, the cutoff value of ammonium concentration produced by embryos was 16.07μmol/L (AUC = 0.722, 95% CI 0.637-0.807; P = 0.000), so all embryos were assigned to two groups according to the cutoff value: normal group (< 16.07μmol/L) and increased group (≥ 16.07μmol/L). There was a significant difference in blastocyst formation rate (80.5% vs 59.0%, P < 0.01) between normal group and increased group, as well as for good-quality blastocyst rate (21.0% vs 3.4%, P < 0.01). A significantly higher expression level of Bax (P < 0.05) and considerably lower expression level of Oct4 (P < 0.01) were observed in increased group compared to normal group. Our data demonstrated for the first time that increased ammonium concentration in culture medium may promote cellular apoptosis and negatively affect pluripotency of human blastocyst.

The Neurospora crassa molybdate transporter: Characterizing a novel transporter homologous to the plant MOT1 family

Molybdenum (Mo) is an essential element for animals, plants, and fungi. To achieve biological activity in eukaryotes, Mo must be complexed into the molybdenum cofactor (Moco). Cells are known to take up Mo in the form of the oxyanion molybdate. However, molybdate transporters are scarcely characterized in the fungal kingdom. In plants and algae, molybdate is imported into the cell via two families of molybdate transporters (MOT), MOT1 and MOT2. For the filamentous fungus Neurospora crassa, a sequence homologous to the MOT1 family was previously annotated. Here we report a characterization of this molybdate-related transporter, encoded by the ncmot-1 gene. We found that the deletion of ncmot-1 leads to an accumulation of total Mo within the mycelium and a roughly 51 % higher tolerance against high molybdate levels when grown on ammonium medium. The localization of a GFP tagged NcMOT-1 was identified among the vacuolar membrane. Thereby, we propose NcMOT-1 as an exporter, transporting molybdate out of the vacuole into the cytoplasm. Lastly, the heterologous expression of NcMOT-1 in Saccharomyces cerevisiae verifies the functionality of this protein as a MOT. Our results open the way towards understanding molybdate transport as part of Mo homeostasis and Moco-biosynthesis in fungi.

Emulsion liquid membrane for simultaneous extraction and separation of copper from nickel in ammoniacal solutions

The separation of copper and nickel in ammonia solution is challenging in hydrometallurgy. In this work, an emulsion liquid membrane (ELM) was constructed using M5640 as an extractant, Span 80 as a non-ionic surfactant, and kerosene as a solvent for the selective separation of Cu(II) and Ni(II) in ammoniacal/ammonium chloride solutions. First, the stability of the emulsion liquid membrane was evaluated, and the parameters were optimized by response surface methodology (RSM). Subsequently, the critical factors affecting the separation of copper and nickel in ammonia solution, including extractant concentration, feed pH, internal phase concentration, and emulsification speed, were systematically studied. The results show that > 99.9 % of Cu(II) migrates from the feed phase to the internal phase, while only < 4.2 % of Ni (II) migrates. The separation coefficient of Cu(II) and Ni(II) reaches 114,000, indicating that the emulsion membrane can effectively separate Cu(II) and Ni(II) in an ammonia medium. Furthermore, the discussion on the separation mechanism shows that the difference in the reaction kinetics of Cu(NH3)42+ and Ni(NH3)62+ with M5640 is the main reason for the selective separation of Cu(II) and Ni(II) in ammonia solution.