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1.
Food Res Int ; 190: 114595, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38945610

ABSTRACT

R-phycoerythrin (R-PE) is the most abundant, naturally occurring phycobiliproteins found in red algae. The spectroscopic and structural properties of phycobiliproteins exhibit unique absorption characteristics with two significant absorption maxima at 498 and 565 nm, indicating two different chromophores of R-PE, phycourobilin and phycoerythrobilin respectively. This study aimed to clarify how the stability of R-PE purified from F. lumbricalis was affected by different purification strategies. Crude extracts were compared to R-PE purified by i) microfiltration, ii) ultrafiltration, and iii) multi-step ammonium sulphate precipitation followed by dialysis. The stability of the different R-PE preparations was evaluated with respect to pH (2, 4, 6, 7, 8, 10 and 12) and temperature (20, 40, 60, 80 and 100 °C). The absorbance spectra indicated higher stability of phycourobilin as compared to phycoerythrobilin for heat and pH stability in the samples. All preparations of R-PE showed heat stability till 40 °C from the findings of color, concentration of R-PE and fluorescence emission. The crude extract showed stability from pH 6 to 8, whereas R-PE purified by ultrafiltration and multi-step ammonium sulphate precipitation were both stable from pH 4 to 8 and R-PE purified by microfiltration exhibited stability from pH 4 to 10 from the results of color, SDS-PAGE, and concentration of R-PE. At pH 2, the color changed to violet whereas a yellow color was observed at pH 12 in the samples along with the precipitation of the protein.


Subject(s)
Phycoerythrin , Rhodophyta , Phycoerythrin/chemistry , Phycoerythrin/isolation & purification , Hydrogen-Ion Concentration , Rhodophyta/chemistry , Ultrafiltration/methods , Protein Stability , Chemical Precipitation , Ammonium Sulfate/chemistry , Hot Temperature , Temperature
2.
Article in English | MEDLINE | ID: mdl-38376782

ABSTRACT

Gas-permeable membrane (GPM) technology is gaining interest to recover nitrogen from residual effluents due to its effectiveness, simple operation and capacity of producing a nutrient rich product with fertilising value. In this study, a GPM contactor was used at 25 °C to recover total ammoniacal nitrogen (TAN) from swine slurry as a concentrated (NH4)2SO4 solution. Firstly, a synthetic solution was tested on a wide pH range (6-12). Results showed that the ammonia mass transfer constants (Km) increased from 7.9·10-9 to 1.2·10-6 m/s as the pH increased. The reagent consumption to control the pH per mole nitrogen recovered had a minimum at pH 9, which showed a Km value of 3.0·10-7 m/s. Secondly, various pH control strategies were tested using swine slurry, including (i) no pH control, (ii) pH control at 8.5, 9.0 and 10.0, and (iii) an initial spike of the NaOH equivalent to the required to control the pH at 9. The test without pH control reached a TAN recovery of around 60%, which could be an interesting strategy when high nitrogen recoveries or short operating times are not required. The pH control at 9 stood out as the most favourable operating condition due to its high Km and lower reagent consumption. Thirdly, several feed-to-trapping volume ratios ranging from 1:1 to 15:1 were tested using swine slurry at pH 9. These assays revealed that a GPM process with a high feed-to-trapping volume ratio fastens the recovery of 99% of TAN as a high purity (NH4)2SO4 solution containing 40 g N/L.

3.
MethodsX ; 11: 102435, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37876828

ABSTRACT

Accurate genomic sequencing demands high-quality double-stranded RNA (dsRNA). Existing methods for dsRNA extraction from yeast, fungi, and plants primarily rely on cellulose, suitable only for small volume extractions, or the time-consuming lithium chloride precipitation. To streamline the traditional phenol-chloroform-based dsRNA extraction method, the main challenge is the reduction of mitochondrial DNA (mtDNA) and Single Stranded RNA (ssRNA) to no detectable levels after gel electrophoresis. This challenge is successfully addressed through the modified approach described here, involving phenol extraction at low pH, followed by the addition of ammonium sulfate to the aqueous buffer. The dsRNA isolated using this novel method exhibits comparable quality to that obtained through cellulose purification, and it is readily amenable to RT-PCR. Moreover, a single batch of yeast cell RNA isolation requires only 2-3 h of hands-on time, thus simplifying and expediting the process significantly.•Buffers were redesigned from [32,33,35].•No DNASE, Ribonuclease A or beads were used during the purification.•Simple and inexpensive dsRNA extraction and purification method is described.

4.
Sci Total Environ ; 903: 166044, 2023 Dec 10.
Article in English | MEDLINE | ID: mdl-37572921

ABSTRACT

With a global population of eight billion people, improving the sustainability and nutritional quality of diets has become critical. Mushrooms offer a promising solution because of their nutritional value and ability to be grown from agricultural residues, in line with the circular economy. This study, therefore, focuses on assessing the environmental compatibility of Agaricus bisporus mushroom production in Italy, the world's third largest per capita consumer, by using a Life Cycle Assessment (LCA) and an integrated Water-Energy-Nitrogen-Carbon-Food (WENCF) nexus analysis. The LCA results reveal that for a functional unit of 23,000 kg of the substrate, the production process emits 2.55 × 104 kg of CO2 eq. Sensitivity analysis shows that changing input quantities can reduce environmental impacts by about 5 %. In addition, one scenario evaluates the environmental effects of recycling resources by introducing water and ammonium sulfate from scratch instead of continuous recycling, along with water purification. The study shows that sustainable food production can mitigate resource depletion, climate-altering emissions, and intersectoral competition. Using agro residues for mushroom cultivation and optimizing resource management contribute to environmental sustainability. This approach could not only improve the resilience and efficiency of the food system but could also improve the sustainability of diets. In conclusion, this study highlights the importance of adopting sustainable and circular approaches in mushroom production to address global challenges related to food sustainability.

5.
Methods Mol Biol ; 2686: 509-536, 2023.
Article in English | MEDLINE | ID: mdl-37540375

ABSTRACT

Understanding the global and dynamic nature of plant developmental processes requires not only the study of the transcriptome, but also of the proteome, including its largely uncharacterized peptidome fraction. Recent advances in proteomics and high-throughput analyses of translating RNAs (ribosome profiling) have begun to address this issue, evidencing the existence of novel, uncharacterized, and possibly functional peptides. To validate the accumulation in tissues of sORF-encoded polypeptides (SEPs), the basic setup of proteomic analyses (i.e., LC-MS/MS) can be followed. However, the detection of peptides that are small (up to ~100 aa, 6-7 kDa) and novel (i.e., not annotated in reference databases) presents specific challenges that need to be addressed both experimentally and with computational biology resources. Several methods have been developed in recent years to isolate and identify peptides from plant tissues. In this chapter, we outline two different peptide extraction protocols and the subsequent peptide identification by mass spectrometry using the database search or the de novo identification methods.


Subject(s)
Proteomics , Tandem Mass Spectrometry , Chromatography, Liquid/methods , Proteomics/methods , Tandem Mass Spectrometry/methods , Peptides/chemistry , Proteome/chemistry , Flowers
6.
Soil Use Manag ; 38(1): 622-634, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35873863

ABSTRACT

Ammonium sulphate is widely used as a sulphur (S) fertilizer, constituting about 50% of global S use. Within nitrogen (N) management, it is well known that ammonium-based fertilizers are subject to ammonia (NH3) volatilization in soils with pH > 7, but this has been overlooked in decision making on S fertilization. We reviewed 41 publications reporting measurements of NH3 loss from ammonium sulphate in 16 countries covering a wide range of soil types and climates. In field experiments, loss was mostly <5% of applied N in soils with pH (in water) <7.0. In soils with pH > 7.0, there was a wide range of losses (0%-66%), with many in the 20%-40% range and some indication of increased loss (ca. 5%-15%) in soils with pH 6.5-7.0. We estimate that replacing ammonium sulphate with a different form of S for arable crops could decrease NH3 emissions from this source by 90%, even taking account of likely emissions from alternative fertilizers to replace the N, but chosen for low NH3 emission. For every kt of ammonium sulphate replaced on soils of pH > 7.0 in temperate regions, NH3 emission would decrease from 35.7 to 3.6 t NH3. Other readily available sources of S include single superphosphate, potassium sulphate, magnesium sulphate, calcium sulphate dihydrate (gypsum), and polyhalite (Polysulphate). In view of the large areas of high pH soils globally, this change of S fertilizer selection would make a significant contribution to decreasing NH3 emissions worldwide, contributing to necessary cuts to meet agreed ceilings under the Gothenburg Convention.

7.
Gels ; 8(4)2022 Mar 23.
Article in English | MEDLINE | ID: mdl-35448105

ABSTRACT

The development of Fricke gel (FG) dosimeters based on poly(vinyl alcohol) (PVA) as the gelling agent and glutaraldehyde (GTA) as the cross-linker has enabled significant improvements in the dose response and the stability over time of spatial radiation dose distributions. However, a standard procedure for preparing FG in terms of reagent concentrations is still missing in the literature. This study aims to investigate, by means of spectrophotometric analyses, how the sensitivity to the radiation dose and the range of linearity of the dose-response curve of PVA-GTA-FG dosimeters loaded with xylenol orange sodium salt (XO) are influenced by ferrous ammonium sulphate (FAS) and XO concentrations. Moreover, the effect of different concentrations of such compounds on self-oxidation phenomena in the dosimeters was evaluated. PVA-GTA-FG dosimeters were prepared using XO concentrations in the range 0.04-0.80 mM and FAS in the range 0.05-5.00 mM. The optical absorbance properties and the dose response of FG were investigated in the interval 0.0-42.0 Gy. The results demonstrate that the amount of FAS and XO determines both the sensitivity to the absorbed dose and the interval of linearity of the dose-response curve. The study suggests that the best performances of FG dosimeters for spectrophotometric analyses can be obtained using 1.00-0.40 mM and 0.200-0.166 mM concentrations of FAS and XO, respectively.

8.
Heliyon ; 8(1): e08690, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35028467

ABSTRACT

Grasslands cover up to 40.5% of the world's landmass and store 30% terrestrial carbon (C). Various practices, including mineral fertilization and liming, are used to manage these ecosystems with potential long-term effects on the size and distribution of soil aggregates and inevitably carbon dynamics. The objective of this study was to examine the long-term effects of nitrogen fertilization and liming on soil carbon storage and its dynamics in water-stable aggregates of a semi-arid grassland. Soil samples (0-10 cm) were collected from Ukulinga long-term grassland trial in Pietermaritzburg, South Africa where nitrogen fertilizers have been applied annually and lime every five years for 70 years. Ten treatments were studied: the control (0 kgN/ha and unlimited), lime at 2250 kg/ha (L), ammonium sulphate at 70 kg/ha (AS70) and 211 kg/ha (AS211); ammonium nitrate at 70 kg/ha (AN70) and 211 kg/ha (AN211); AS70 + lime (AS70L); AS211 + lime (AS211L); AN70 + lime (AN70L) and AN211 + lime (AN211L). Nitrogen fertilizers significantly reduced soil pH and increased total soil N. Liming increased soil pH with no effect on total soil N. Lime and lime + N fertilizer treatments had no effect on mean weight diameter (MWD) while separate N application decreased MWD and large macro-aggregates (LMA). Lime only treatment had no effect on water stable aggregate (WSA) fractions. Nitrogen fertilization and liming (separately or in combination) did not affect total C concentration and stocks. Overall, soils had very high total soil organic carbon ranging from 49.7 - 57.6 g/kg across treatments. Nitrogen fertilization decreased organic carbon in LMA in AS70 (1.52%) and AN211 (1.67%) treatments compared to the control (3.40%) which was in concert with increases in C associated with small macro-aggregates (SMA) and micro-aggregates (MiA and SCA). Organic carbon in SMA was 2.67 % (AS70); AS211 (2.62 %); AN70 (2.02 %); AN211 (2.49 %) compared to 1.26 % in the control. Lime + N fertilizer treatments increased C storage in all aggregate fractions compared to N fertilizer only treatments. The lack of response in total SOC to 70 years of N fertilization and liming suggests possible C saturation given the high soil C concentration. Changes in C associated with WSA fractions suggests their importance as diagnostic indicators of N fertilization and liming induced changes in SOC. Findings also show that ammonium-based N fertilization is associated with soil acidification, dispersion of LMA resulting in an increase of microaggregates and C stored in them. Liming can counteracts acidifying and the dispersive effect on NH4 + associated with ammonium-based fertilizers thus restoring macro-aggregation in N fertilized grasslands. These findings suggests that long-term N addition may result in poor soil physical condition and possible stabilization of C in stable fractions.

9.
J Clean Prod ; 308: 127408, 2021 Jul 25.
Article in English | MEDLINE | ID: mdl-34316100

ABSTRACT

Anaerobic digestion of nitrogen (N) rich substrates might be hindered when ammonia (NH3) formation reaches toxic levels for methanogenic microorganisms. One possible strategy to avoid inhibiting conditions is the removal of NH3 from digestate by stripping and scrubbing technology and by recirculating N depleted digestate back to the digester. This study aimed to i) monitor the performance (mass and energy balances) of a full scale digestate processing cascade that includes an innovative vacuum side stream NH3stripping and scrubbing system, ii) assess the production cost of ammonium sulphate (AS) solution and iii) evaluate its fertiliser quality. The use of gypsum to recover NH3 in the scrubbing unit, instead of the more common sulphuric acid, results in the generation of AS and a fertilising liming substrate. Mass and nutrient balances indicated that 57% and 7.5% of ammonium N contained in digestate was recovered in the form of a 22% AS and liming substrate, respectively. The energy balance showed that about 3.8 kWhel and 59 kWhth were necessary to recover 1 kg of N in the form of AS. Furthermore, the production cost of AS, including both capital and operational costs, resulted to be 5.8 € t-1 of digestate processed. According to the fertiliser quality assessment, this technology allows for the recovery of NH3in the form of salt solutions that can be utilised as a substitute for synthetic mineral nitrogen fertilisers.

10.
Bioresour Technol ; 337: 125463, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34320743

ABSTRACT

Downstream processing of chemicals obtained from fermentative route is challenging and cost-determining factor of any bioprocess. 2,3-Butanediol (BDO) is a promising chemical building block with myriad applications in the polymer, food, pharmaceuticals, and fuel sector. The current study focuses on the recovery and purification of BDO produced (68.2 g/L) from detoxified xylose-rich sugarcane bagasse hydrolysate by a mutant strain of Enterobacter ludwigii. Studies involving screening and optimization of aqueous-two phase system (ATPS) revealed that 30% w/v (NH4)2SO4 addition to clarified fermented broth facilitated BDO extraction in isopropanol (0.5 v/v), with maximum recovery and partition coefficient being 97.9 ± 4.6% and 45.5 ± 3.5, respectively. The optimized protocol was repeated with unfiltered broth containing 68.2 g/L BDO, cell biomass, and unspent protein, which led to the partitioning of 66.7 g/L BDO, 2.0 g/L xylose and 9.0 g/L acetic acid into organic phase with similar BDO recovery (97%) and partition coefficient (45).


Subject(s)
Saccharum , Xylose , Butylene Glycols , Cellulose , Enterobacter , Fermentation
11.
Waste Manag ; 124: 356-367, 2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33662767

ABSTRACT

This work reports a full-scale study in which organic wastes were transformed by high-solid thermophilic anaerobic digestion (HSAD), into N fertilizers and organic fertilizers, i.e. digestate. The produced fertilizers were characterized over 42 months and their properties were discussed in comparisons with literature data. HSAD coupled with N stripping technology led to ammonia sulphate production having high N concentration (74 ± 2 g kg-1 wet weight), neutral pH (6.8 ± 1.3) and low traces of other elements. Digestate showed both higher carbon (C) content (314 ± 30 g kg-1 on dry matter (DM) and biological stability than green composts, indicating good amendment properties. Digestate was also interesting for its N (77 ± 3.7 g kg-1 dry matter - DM) content, half of it in the ammonia form, and P content (28 ± 4.1 g kg-1 DM) that was 43% readily available as soluble P-orthophosphate. K content was low (6.5 ± 1.3 g kg-1 DM), indicating poor fertilizing ability of digestate for this element. All organic pollutants investigated were much lower than the limits required for agricultural use and levels of some of them were lower than the content revealed for other organic matrices such as agricultural and energy crop digestates and compost. Emerging pollutants (i.e., pharmaceuticals) were tested as markers and they were found to be below the detection limit (<0.01 mg kg-1 DM) indicating very low content. The results obtained showed that HSAD coupled with N stripping allowed transforming sewage sludge into fertilizers and soil improvers exploitable in agriculture.


Subject(s)
Agriculture , Fertilizers , Anaerobiosis , Fertilizers/analysis , Sewage , Soil
12.
Food Chem ; 341(Pt 1): 128180, 2021 Mar 30.
Article in English | MEDLINE | ID: mdl-33032249

ABSTRACT

Lactobacillus helveticus FAM22155 was the most efficient among five lactic acid bacteria at removing aflatoxin B1 (AFB1) during solid-state fermentation on wheat bran substrate. The mechanism of removal was explored by comparing different fermentation modes. Liquid fermentation had little effect on the breakdown of AFB1. However, a protein extract from the fermented bran was equally effective at degrading aflatoxin B1 as living cell digestion. After treatment with heat and protease K, the degrading capacity of the protein extract was significantly reduced. Taken together, the observed biotransformation of AFB1 was mainly associated with proteins produced during bran fermentation. Four products of U-[13C17]-AFB1 were found by mass spectrometry, including Ⅱ-1 (C11H10O4), Ⅱ-2 (C11H10O4), III (C15H12O5), and IV (C14H10O4). These products all lack the lactone ring indicating lower toxicity than aflatoxin B1.


Subject(s)
Aflatoxin B1/metabolism , Dietary Fiber/microbiology , Lactobacillus helveticus/metabolism , Aflatoxin B1/analysis , Biotransformation , Dietary Fiber/metabolism , Fermentation , Food Microbiology , Lactobacillales/metabolism
13.
Braz. arch. biol. technol ; 64: e21200639, 2021. tab, graf
Article in English | LILACS | ID: biblio-1278433

ABSTRACT

Abstract Ananas Comosus (also known as pineapple) is a part of Bromeliaceae family and it is consumed as food as well as folk medicine for the treatment of various diseases. It is reported that pineapple is a rich source of bromelain, a cysteine protease and it is considered as an important enzyme in different industries due to its significant therapeutic and industrial applications such as anticancer, anti-inflammatory and meat tenderizing. Bromelain is mostly present in fruit and stem of pineapple, but it is reported that crown, core, and peels, which constitute the waste of the pineapple plant, also contain bromelain but limited data is available. Therefore, the proposed study aimed at utilizing pineapple waste for the extraction and characterization of bromelain. Firstly, crude bromelain was extracted with phosphate buffer (pH 7), then it was subjected to partial purification using different fractions of ammonium sulphate (NH4)2SO4 such as 30, 40, 50 and 60% followed by desalting and concentration. Enzyme activity was calculated by using casein digesting unit (CDU) method. The results demonstrated that the crown bromelain showed highest purification of 4.34-fold at 30% (NH4)2SO4 saturation, whereas core and peel bromelain showed highest purification of 2.75 and 2.59-fold at 40% (NH4)2SO4 saturation. The molecular weight of crude and partially purified bromelain was determined by SDS-PAGE analysis and found to be 26 KDa. The pH and thermal stability of all the parts of pineapple showed maximum stability at pH 7 and at 35oC temperature.


Subject(s)
Bromelains/isolation & purification , Enzyme Activation , Ammonium Sulfate , Peptide Hydrolases , Electrophoresis, Polyacrylamide Gel
14.
Food Res Int ; 136: 109543, 2020 10.
Article in English | MEDLINE | ID: mdl-32846598

ABSTRACT

Milk is regarded as one of the top food products susceptible to adulteration where its valuable components are specifically identified as high-risk indicators for milk fraud. The current study explores the impact of common milk adulterants on the apparent compositional parameters of milk from the Dutch market as measured by standardized Fourier transform infrared (FTIR) spectroscopy. More precisely, it examines the detectability of these adulterants at various concentration levels using the compositional parameters individually, in a univariate manner, and together in a multivariate approach. In this study we used measured boundaries but also more practical variance-adjusted boundaries to set thresholds for detection of adulteration. The potential economic impact of these adulterations under a milk payment scheme is also evaluated. Twenty-four substances were used to produce various categories of milk adulterations, each at four concentration levels. These substances comprised five protein-rich adulterants, five nitrogen-based adulterants, seven carbohydrate-based adulterants, six preservatives and water, resulting in a set of 360 samples to be analysed. The results showed that the addition of protein-rich adulterants, as well as dicyandiamide and melamine, increased the apparent protein content, while the addition of carbohydrate-based adulterants, whey protein isolate, and skimmed milk powder, increased the apparent lactose content. When considering the compositional parameters univariately, especially protein- and nitrogen-based adulterants did not raise a flag of unusual apparent concentrations at lower concentration levels. Addition of preservatives also went unnoticed. The multivariate approach did not improve the level of detection. Regarding the potential profit of milk adulteration, whey protein and corn starch seem particularly interesting. Combining the artificial inflation of valuable components, the resulting potential profit, and the gaps in detection, it appears that the whey protein isolates deserve particular attention when thinking like a criminal.


Subject(s)
Food Contamination , Milk , Animals , Food Contamination/analysis , Fourier Analysis , Lactose , Spectroscopy, Fourier Transform Infrared
15.
J Environ Manage ; 270: 110692, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32721283

ABSTRACT

The organic matter and nitrogen contents of swine wastewater (SW) can be reduced and, at the same time, a fertiliser as ammonium salt can be recovered by wastewater treatments. One of the most promising technique is air stripping (AS). However, the operational parameters (pH, temperature and air flow rate) of AS must be optimised, in order to maximise the ammonia recovery and reduce the requirement of chemicals and energy. In this study 27 batch tests at laboratory scale were carried out on real SW, varying (individually or simultaneously) the pH (not adjusted, 8 and 10), temperature (ambient, 40 and 60 °C) and flow rate (0, 1 and 5 Lair LSW-1 min-1) of AS; the changes in soluble COD (sCOD) and total ammonia nitrogen (TAN) concentrations were evaluated in response to the parameters adjustments. For the tests including AS, the ammonium sulphate recovered was also measured. In general (about 50% of the tests), more than 80% of TAN was removed. Most of these tests were carried out with pH and temperature control and AS at the highest flow rate; the highest efficiency was found for a combination of chemical, thermal and aeration treatments. For a few tests with the same process control, an increase (up to 50%) or a very limited (less than 10%) decrease of sCOD were detected; therefore, these treatments can be adopted prior of anaerobic digestion of SW. A high flow rate, which increases the removal efficiency of both sCOD and TAN, should be adopted, when AS is used as pre-treatment of activated sludge or lagooning plants. Very high amounts (over 80% of the theoretical yield) of ammonium sulphate were recovered by AS at the maximum air flow rate (5 Lair LSW-1 min-1), which would provide a nitrogen fertiliser at a sustainable cost.


Subject(s)
Ammonia/analysis , Wastewater , Animals , Bioreactors , Nitrogen/analysis , Sewage , Swine , Waste Disposal, Fluid
16.
J Environ Manage ; 259: 109841, 2020 Apr 01.
Article in English | MEDLINE | ID: mdl-32072955

ABSTRACT

A process for the continuous extraction of ammonia from anaerobic digesters is proposed. In this process, a portion of the sludge treated in the digesters is continuously withdrawn and transferred to a thin film evaporator (TFE) unit, where the ammonia is stripped through a biogas stream. The ammonia-rich biogas is treated with a sulfuric acid/water solution in a reactive absorption unit, with production of ammonium sulphate. The chemistry of a CH4/CO2/NH3 gas phase in thermodynamic equilibrium with a liquid sulfuric acid/water solution is investigated theoretically, with focus on the simultaneous absorption of CO2 and NH3 into the liquid phase. Pilot plant experimental data confirm the theoretical results. Further pilot plant experimental results obtained during on-off cycles of the stripping equipment demonstrate that, when the TFE unit is off, ammonia concentration in the digestate rises quickly, while, when the stripping equipment is turned on again, ammonia concentration drops down. On average, during the 180 days of pilot plant experimentation, 4.1 g N-NH4 per kg of sludge fed to the digester, i.e. 19.3 g N-NH4 per kg of total solids (TS) fed to the digester, are stripped from digestate and recovered as ammonium sulphate, demonstrating the feasibility of the proposed concept.


Subject(s)
Ammonia , Biofuels , Ammonium Sulfate , Anaerobiosis , Bioreactors , Sewage
17.
Waste Manag ; 102: 815-822, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-31812833

ABSTRACT

Generation of calcium vanadate waste sludge their management and treatment.is one of the major problem of metal processing industry. In this paper, we have proposed a simple process for the selective recovery of vanadium as ammonium metavanadate (AMV) from the calcium vanadate sludge using ammonium sulphate (AS) as a leaching agent. Under the optimum leaching condition (pH-7.5, temperature-80 °C, time-1 h, AS reagent-0.5 M) it is possible to leach out 82% of V values from the calcium vanadate sludge. The overall recovery of V is 81% with 98.5% AMV product purity. The AMV product quality from AS leach process has been compared with conventional H2SO4 leach process. The proposed process has major advantages such as, better economic benefits, less chemical consumption, minimum effluent recycling and less waste generation.


Subject(s)
Vanadates , Vanadium , Ammonium Sulfate , Calcium , Industrial Waste , Sewage
18.
Sci Total Environ ; 718: 134748, 2020 May 20.
Article in English | MEDLINE | ID: mdl-31848057

ABSTRACT

Agricultural sustainability is compromised by nitrogen (N) losses caused by soil microbial activity. Nitrous oxide (N2O) is a potent greenhouse gas (GHG) produced as consequence of nitrification and denitrification processes in soils. Nitrification inhibitors (NI) as 3,4-dimethylpyrazole-succinic acid (DMPSA) are useful tools to reduce these N losses from fertilization. The objective of this work was to test the efficiency of DMPSA in two different tillage management systems, conventional tillage (CT) and no-tillage (NT), in a winter wheat crop under Humid Mediterranean conditions. N fertilizer was applied as ammonium sulphate (AS) with or without DMPSA in a single or split application, including an unfertilized treatment. GHG fluxes (N2O, CO2 and CH4) were measured by the closed chamber method. amoA and nosZI genes were quantified by qPCR as indicators of nitrifying and denitrifying populations. Nitrification was inhibited by DMPSA in both CT and NT, while the higher water filled pore space (WFPS) in NT promoted a better efficiency of DMPSA in this system. This higher efficiency might be due to a greater N2O reduction to N2 as result of the nosZI gene induction. Consequently, DMPSA was able to reduce N2O emissions down to the unfertilized levels in NT. Provided that NT reduced CO2 emissions and maintained crop yield compared to CT, the application DMPSA under NT management is a promising strategy to increase agro-systems sustainability under Humid Mediterranean conditions.


Subject(s)
Nitrification , Agriculture , Fertilizers , Nitrous Oxide , Soil , Succinic Acid
19.
Biotechnol Lett ; 41(11): 1309-1318, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31559517

ABSTRACT

Chaotropes are compounds which cause the disordering, unfolding and denaturation of biological macromolecules. It is the chaotropicity of fermentation products that often acts as the primary limiting factor in ethanol and butanol fermentations. Since ethanol is mildly chaotropic at low concentrations, it prevents the growth of the producing microbes via its impacts on a variety of macromolecular systems and their functions. Kosmotropes have the opposite effect to chaotropes and we hypothesised that it might be possible to use these to mitigate chaotrope-induced inhibition of Saccharomyces cerevisiae growth. We also postulated that kosmotrope-mediated mitigation of chaotropicity is not quantitatively predictable. The chaotropes ethanol and urea, and compatible solutes glycerol and betaine (kosmotrope), and the highly kosmotropic salt ammonium sulphate all inhibited the growth rate of Saccharomyces cerevisiae in the concentration range 5-15%. They resulted in increased lag times, decreased maximum specific growth rates, and decreased final optical densities. Surprisingly, neither the stress protectants nor ammonium sulphate reduced the inhibition of growth caused by ethanol. Whereas, in some cases, compatible solutes and kosmotropes mitigated against the inhibitory effects of urea. However, this effect was not mathematically additive from the quantification of chao-/kosmotropicity of each individual compound. The potential effects of glycerol, betaine and/or ammonium sulphate may have been reduced or masked by the metabolic production of compatible solutes. It may nevertheless be that the addition of kosmotropes to fermentations which produce chaotropic products can enhance metabolic activity, growth rate, and/or product formation.


Subject(s)
Biofuels/microbiology , Models, Biological , Saccharomyces cerevisiae , Ammonium Sulfate/pharmacology , Betaine/metabolism , Culture Media/chemistry , Culture Media/pharmacology , Entropy , Ethanol/metabolism , Ethanol/pharmacology , Fermentation , Glycerol/metabolism , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/metabolism , Urea/pharmacology
20.
Food Res Int ; 121: 506-513, 2019 07.
Article in English | MEDLINE | ID: mdl-31108775

ABSTRACT

Long-term storage of common beans leads to loss of cooking quality and an ill-defined solution, appropriate storage, is recommended. Therefore, the polymer science theory of glasses that hypothesizes stability of a system below its glass transition temperature (Tg) was applied to determine bean stability during storage in relation to cooking behavior. Since composition influences Tg, powders of cotyledons and seed coats in addition to whole beans were equilibrated above different saturated salt solutions in order to generate materials with different moisture contents. A thermal mechanical compression test which measures compressibility changes in a system upon reaching its glass-rubber transition temperature region was conducted to obtain the Tg. A Tg-moisture relation was established, whose relevance was confirmed by storage and cooking experiments which showed development of hard-to-cook in beans stored above Tg but not below it. Therefore, this relation constitutes a stability map for storage of common beans.


Subject(s)
Cooking , Food Storage , Phaseolus/chemistry , Vitrification , Cotyledon/chemistry , Food Quality , Hardness , Hot Temperature , Particle Size , Seeds/chemistry , Transition Temperature
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