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Sulfate is a critical component of schwertmannite. However, the sulfate content of schwertmannite decreases with the increase in AMD-polluted river pH value, and its impact on the surface properties and Cr(VI) adsorption of schwertmannite remains unclear. To address this issue, different methods, including batch adsorption, N 2 physisorption, scanning electron microscopy (SEM), potentiometric titration, X-ray photoelectron spectroscopy (XPS), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR) in combination with two-dimensional correlation spectroscopy (2D-COS) analysis, and surface complexation modeling (SCM) were employed. Our results showed that sulfate existed as both non-protonated bidentate-binuclear complexes and non-protonated outer-sphere complexes in schwertmannite. The surface morphology and particle size of schwertmannite were unaffected by the sulfate content. However, a decrease in sulfate content resulted in a drop in the negative charge on the surface of schwertmannite, which is conducive to particle aggregation. An increase in pH, on the other hand, raised the negative charge and encouraged the dispersion of the particles. And then, reducing the sulfate content of schwertmannite led to a decrease in acid-base buffer and Cr(VI) adsorption capacity of schwertmannite. The adsorption process of Cr(VI) by schwertmannite can be divided into two stages. In the first stage, Cr(VI) was adsorbed primarily through anion exchange reactions with the sulfate; however, the contribution of surface complexation gradually increased as the initial sulfate content decreased because of a reduced likelihood of anion exchange and an increase in the specific surface area of schwertmannite. Additionally, the behavior of sulfate and Cr(VI) in this stage could be predicted based on the initial sulfate content of schwertmannite. In the second stage, surface complexation with hydroxyl sites became the predominant mechanism of adsorption, which still exhibited great potential at higher Cr(VI) concentrations. Finally, the aforementioned hypothesis was used to establish a CD-MUSIC model, and the fitting results demonstrated that the density and Cr(VI) adsorption capacity of the sulfate site dropped as the sulfate content decreased, while the hydroxyl site was less impacted. The findings have provided insights into further understanding the properties of schwertmannite and its adsorption of Cr(VI). [ABSTRACT FROM AUTHOR]

Fucoidans are a heterogenous class of sulfated, fucose-rich, and high molecular weight polysaccharides derived mainly from brown seaweeds. They have attracted particular interest in different scientific and industrial fields. Nevertheless, their applications are affected by various chemical properties, including molecular weight, sulfation pattern, and degree of sulphation. For instance, most of the reported bioactivities (e.g., immunomodulatory and cytotoxic activities) have been enhanced with more sulfated and low molecular weight fractions, in contrast to the anticoagulant effect. Additionally, high molecular weight fucoidans are unsuitable for nanomedicine formulation, oral absorption, and distribution to various body organs. Hence, different strategies have been developed as a subsequent stage of processing to modify the native fucoidans in order to produce more bioactive and efficiently formulated products. The current article highlights the various enzymatic (e.g., fucoidanase and fucoidan sulfatase), chemical, and other strategies used for structural modifications of native fucoidans accompanied by varied bioactivities. Interestingly, the enzymatic method has proved to be more specific and selective retaining the native sulfated chemical backbone efficiently. Hence, this review may help in tayloring new fucoidan derivatives for targeted homogenous production and maximized applications of fucoidans in the medical and pharmaceutical fields. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of fibre oxidation on the extent of substituted sulfate on cellulose nanocrystals (CNC). In this investigation, fully bleached softwood (SW) and hardwood (HW) pulps from an Alberta pulp mill were oxidized under low (4%), medium (10%), and the higher-end of medium (14%) oxygen consistencies. The oxidized pulp samples were hydrolyzed with concentrated sulfuric acid under conventional procedures to produce CNC. The CNC materials were then characterized by different qualitative and quantitative techniques to evaluate the effect of oxidations on the number of substituted sulfates and the overall sulfate charge of isolated CNC to develop novel high-value applications. The experimental data show that fibre oxidation helped improve the overall CNC yield, with lower half-ester sulfate contents compared to the controls. The half-ester sulfate contents and the viscosity for SW CNC were found to be higher than their HW CNC counterparts. However, the thermal stability of CNC was found to be better for HW than SW pulps. The emerging data help to prepare and engineer CNC tailored to specific applications.

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Sulfur plays a vital role in the primary and secondary metabolism of plants, and carries an important function in a large number of different compounds. Despite this importance, compared to other mineral nutrients, relatively little is known about sulfur sensing and signalling, as well as about the mechanisms controlling sulfur metabolism and homeostasis. Sulfur contents in plants vary largely not only among different species, but also among accessions of the same species. We previously used associative transcriptomics to identify several genes potentially controlling variation in sulfate content in the leaves of Brassica napus, including an OASC gene for mitochondrial O-acetylserine thiollyase (OAS-TL), an enzyme involved in cysteine synthesis. Here, we show that loss of OASC in Arabidopsis thaliana lowers not only sulfate, but also glutathione levels in the leaves. The reduced accumulation is caused by lower sulfate uptake and translocation to the shoots; however, the flux through the pathway is not affected. In addition, we identified a single nucleotide polymorphism in the OASC gene among A. thaliana accessions that is linked to variation in sulfate content. Both genetic and transgenic complementation confirmed that the exchange of arginine at position 81 for lysine in numerous accessions resulted in a less active OASC and a lower sulfate content in the leaves. The mitochondrial isoform of OAS-TL is, thus, after the ATPS1 isoform of sulfurylase and the APR2 form of APS reductase 2, the next metabolic enzyme with a role in regulation of sulfate content in Arabidopsis. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of fibre oxidation on the extent of substituted sulfate on cellulose nanocrystals (CNC). In this investigation, fully bleached softwood (SW) and hardwood (HW) pulps from an Alberta pulp mill were oxidized under low (4%), medium (10%), and the higher-end of medium (14%) oxygen consistencies. The oxidized pulp samples were hydrolyzed with concentrated sulfuric acid under conventional procedures to produce CNC. The CNC materials were then characterized by different qualitative and quantitative techniques to evaluate the effect of oxidations on the number of substituted sulfates and the overall sulfate charge of isolated CNC to develop novel high-value applications. The experimental data show that fibre oxidation helped improve the overall CNC yield, with lower half-ester sulfate contents compared to the controls. The half-ester sulfate contents and the viscosity for SW CNC were found to be higher than their HW CNC counterparts. However, the thermal stability of CNC was found to be better for HW than SW pulps. The emerging data help to prepare and engineer CNC tailored to specific applications. [ABSTRACT FROM AUTHOR]

In an undisturbed state below the water table, the sulfidic soils are benign, unless exposed due to various natural processes or anthropogenic activities and sulfuric acidity is produce, which has negative impacts on the environment. This paper examines the effects of organic matter, organic matter co-existing with live plants or live plants alone on sulfidic soil pH, redox and sulfate content under flooded conditions. In almost all cases, organic matter without plants induced ameliorative effects on sulfidic soil chemistry. In soils with or without organic matter, presence of plants led to higher Eh values, lower pH and higher sulfate contents. The reduction reactions of the added organic matter and the anoxia created by flooding were ineffective in reducing the amount of oxygen that was pumped into the rhizophore via the arenchymatous tissues in all the soils with plants. Under falling soil moisture regimes, e.g. during a drought event, presence of this type of plant species would aerate the reduced soil conditions. Aeration would then lead to oxidation of sulfides, producing sulfuric acid, which in turn would have negative impacts when released into the environment. One strategic option to reduce the amount of oxygen entering the soil would be to slash the shoots and leave them on the surface to help generate more alkalinity upon decomposition, even if the culm would continue to facilitate oxygen transport.

Sulfur plays a vital role in the primary and secondary metabolism of plants, and carries an important function in a large number of different compounds. Despite this importance, compared to other mineral nutrients, relatively little is known about sulfur sensing and signalling, as well as about the mechanisms controlling sulfur metabolism and homeostasis. Sulfur contents in plants vary largely not only among different species, but also among accessions of the same species. We previously used associative transcriptomics to identify several genes potentially controlling variation in sulfate content in the leaves of Brassica napus, including an OASC gene for mitochondrial O-acetylserine thiollyase (OAS-TL), an enzyme involved in cysteine synthesis. Here, we show that loss of OASC in Arabidopsis thaliana lowers not only sulfate, but also glutathione levels in the leaves. The reduced accumulation is caused by lower sulfate uptake and translocation to the shoots; however, the flux through the pathway is not affected. In addition, we identified a single nucleotide polymorphism in the OASC gene among A. thaliana accessions that is linked to variation in sulfate content. Both genetic and transgenic complementation confirmed that the exchange of arginine at position 81 for lysine in numerous accessions resulted in a less active OASC and a lower sulfate content in the leaves. The mitochondrial isoform of OAS-TL is, thus, after the ATPS1 isoform of sulfurylase and the APR2 form of APS reductase 2, the next metabolic enzyme with a role in regulation of sulfate content in Arabidopsis.

AN-Najaf city is located 61 meters above the sea level in the dry desert of Iraq. It is one of the most important cities in Iraq due to religious tourism and continuously developing urban areas by constructing multi-storey buildings, bridges and shopping malls. This study aims to create a mapping database for sulfate in An-Najaf soil (Najaf centred and Al-Kufa cities’ soil). To evaluate the spatial variability of data, 464 boreholes and in situ tests were selected and analysed using Geographic Information System ArcGIS 10.2.1. The adopted method consisted of four steps: (1) data collection; (2) geotechnical data georeferencing; (3) interpolation methods and (4) establishment of maps. Nine maps were produced for depths 0-35 m for sulfate content in soil. In addition to two maps for sulfate content in groundwater and organic matter content for depths 0-2. Results showed that all the study area and for depths 0-2 meter has very high sulfate content in the soil. Sulfate values varies between 0.36%- 14% where all the results were higher than the permissible limit which is 0.2%. The sulfate content decreases with the depth yet still effective in some areas. Therefore, precautions have to be adopt to avoid risks. One of the precautions is to use sulfate resistance Portland cement (SRPC) for all concrete works that have contact with soil. Groundwater sulfate content in the study area was ranging between 84-239 %. These values were ineffective because they are lower than the permissible limit, which is 1460%. The organic matter content values vary between 0.05-2.34, the greatest part of the study area was lower than the permissible limit 1% and therefore ineffective. The PH values indicate that all the study area was alkaline so it is uninfluential.

κ-Carrageenan is a sulfated galactan extracted from red algae (Rhodophyceae) which has many functions. However, nonfood applications of κ-carrageenan have been limited by its superior gelling and viscosity properties. The effect of ozonation on physicochemical and rheological properties of κ-carrageenan solution at different pH was investigated. κ-Carrageenan solution was prepared in the ratio of 1:100 (w/v) and was treated with dissolved ozone with concentration of 80±2 ppm. This ozonation was conducted at different times and pH. The viscosity of ozone-treated κ-carrageenan solution was analyzed using Brookfield viscometer and the sulfate content was determined using FT-IR spectra and barium chloride-gelatin method. The results show that the viscosity of ozone-treated κ-carrageenan decreases appreciably with time. The highest percentage reduction in viscosity occurs at pH 3, followed by pH 7 and 10. The FT-IR spectra reveals that the chemical structure of degraded κ-carrageenan, in term of sulfate content, is only slightly affected by the ozone treatment.

Soil salinity reduces plant growth and is a major factor that causes decreased agricultural productivity worldwide. Seaweed polysaccharides promote crop growth and improve plant resistance to abiotic stress. In this study, polysaccharides from brown seaweed Lessonia nigrescens polysaccharides (LNP) were extracted and further separated and fractionated. Two acidic polysaccharides (LNP-1 and LNP-2) from crude LNP were obtained and characterized. The latter had a lower molecular weight (MW) (40.2 kDa) than the former (63.9 kDa), but had higher uronic acid and sulfate content. Crude LNP and LNP-2 were composed of mannose, glucuronic acid, fucose, and xylose, whereas LNP-1 has little mannose. Moreover, the effects of the three polysaccharides on plant salt tolerance were investigated. The results showed that crude LNP, LNP-1, and LNP-2 promoted the growth of plants, decreased membrane lipid peroxidation, increased the chlorophyll content, improved antioxidant activities, and coordinated the efflux and compartmentation of intracellular ion. All three polysaccharides could induce plant resistance to salt stress, but LNP-2 was more effective than the other two. The present study allowed to conclude that both MW and sulfate degree contribute to salt resistance capability of polysaccharides derived from L. nigrescens.

Soil salinity reduces plant growth and is a major factor that causes decreased agricultural productivity worldwide. Seaweed polysaccharides promote crop growth and improve plant resistance to abiotic stress. In this study, polysaccharides from brown seaweed Lessonia nigrescens polysaccharides (LNP) were extracted and further separated and fractionated. Two acidic polysaccharides (LNP-1 and LNP-2) from crude LNP were obtained and characterized. The latter had a lower molecular weight (MW) (40.2 kDa) than the former (63.9 kDa), but had higher uronic acid and sulfate content. Crude LNP and LNP-2 were composed of mannose, glucuronic acid, fucose, and xylose, whereas LNP-1 has little mannose. Moreover, the effects of the three polysaccharides on plant salt tolerance were investigated. The results showed that crude LNP, LNP-1, and LNP-2 promoted the growth of plants, decreased membrane lipid peroxidation, increased the chlorophyll content, improved antioxidant activities, and coordinated the efflux and compartmentation of intracellular ion. All three polysaccharides could induce plant resistance to salt stress, but LNP-2 was more effective than the other two. The present study allowed to conclude that both MW and sulfate degree contribute to salt resistance capability of polysaccharides derived from L. nigrescens. [ABSTRACT FROM AUTHOR]

In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM) for general use of the soils. In acid sulfate soils (ASS), addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

The harmful impacts of acid sulfate soils (ASS) on various ecosystems are diverse and management of the impacts needs ecosystem-specific strategies. The importance of subsurface soil carbon and nitrogen for amelioration of sulfuric soil and curtailing of sulfidic soil oxidation as an option for ASS management was investigated in this study. The results showed the mechanisms involved in amelioration of sulfuric soil and curtailing of sulfidic soil oxidation were dependent on amendment and the microbial ecology the resources were capable of supporting microbial metabolism. Glucose as a single nutrient source capable of engaging a few soil microbes was ineffective in ameliorating the sulfuric soil, compared to complex organic matter, which is a source of multiple nutrients and is capable of engaging a diversity of soil microbes. Addition of complex organic matter effectively ameliorated the sulfuric soil and prevented sulfidic soil oxidation. The alkalization processes was limited by resource availability and the processes ceased as resources got depleted. Polynucleotide analysis of at least one group of sulfate reducing bacteria (SRB, Desulfovibrio) showed that the concentrations of these polynucleotides is high when availability of resources is high and decreases as the resource is limited over time. A three-fold increase in RNA and a ten-fold increase in DNA concentrations of the target SRB were measured in soil amended with organic matter and incubated for four weeks; after six weeks, they decreased. [ABSTRACT FROM AUTHOR]

The present study investigates the use of seaweed polysaccharides as biostimulants of seed germination and plant growth. Seventeen species of Moroccan seaweeds were collected and screened for their crude polysaccharide content which ranged from 0.3 to 34% (dry weight basis). Chemical analyses of the obtained polysaccharide-enriched extracts (PEEs) were performed. Two bioassays were carried out to study seed germination and growth-promoting activity of PEEs. In the first experiment, the effect of PEEs on tomato seed germination was carried out under in vitro conditions. Half-strength Murashige-Skoog medium was supplemented with different PEEs at the concentration of 0.2 mg mL−1 (w/v). The germination percentage was recorded daily over 4 days. In a second experiment, tomato plants were grown in greenhouse conditions and watered with aqueous solution of seaweed PEEs (0.1 mg mL−1). After 30 days, the evaluated plant growth parameters were plant length, fresh and dry weight of plants shoots and roots, as well as chlorophyll content. Results showed that six seaweed species were a promising source of PEEs with beneficial effect on germination, plant biomass, and chlorophyll content. Two green seaweeds: Ulva rigida and Codium decorticatum, two red seaweeds: Gigartina sp. and Chondracanthus acicularis, and two brown seaweeds: Fucus spiralis and Bifurcaria bifurcata enhanced seed germination and plant growth. Nevertheless, the PEEs obtained from the red seaweed Gigartina pistillata inhibited seed germination. Principal component analysis of the results showed positive correlation between the sulfate content of PEEs and shoot dry weight as well as chlorophyll content. [ABSTRACT FROM AUTHOR]

AN-Najaf city is located 61 meters above the sea level in the dry desert of Iraq. It is one of the most important cities in Iraq due to religious tourism and continuously developing urban areas by constructing multi-storey buildings, bridges and shopping malls. This study aims to create a mapping database for sulfate in An-Najaf soil (Najaf centred and Al-Kufa cities' soil). To evaluate the spatial variability of data, 464 boreholes and in situ tests were selected and analysed using Geographic Information System ArcGIS 10.2.1. The adopted method consisted of four steps: (1) data collection; (2) geotechnical data georeferencing; (3) interpolation methods and (4) establishment of maps. Nine maps were produced for depths 0-35 m for sulfate content in soil. In addition to two maps for sulfate content in groundwater and organic matter content for depths 0-2. Results showed that all the study area and for depths 0-2 meter has very high sulfate content in the soil. Sulfate values varies between 0.36%- 14% where all the results were higher than the permissible limit which is 0.2%. The sulfate content decreases with the depth yet still effective in some areas. Therefore, precautions have to be adopt to avoid risks. One of the precautions is to use sulfate resistance Portland cement (SRPC) for all concrete works that have contact with soil. Groundwater sulfate content in the study area was ranging between 84-239 %. These values were ineffective because they are lower than the permissible limit, which is 1460%. The organic matter content values vary between 0.05-2.34, the greatest part of the study area was lower than the permissible limit 1% and therefore ineffective. The PH values indicate that all the study area was alkaline so it is uninfluential. [ABSTRACT FROM AUTHOR]

Conventionally, fucoidan from brown macroalgae is extracted by solubilizing cell wall polysaccharides in hot water, acidic/alkali, and organic solvents. This study depicts the use of various green extraction techniques, including ultrasound assisted extraction, enzyme assisted extraction and subcritical water extraction, to isolate fucoidan from brown macroalgae (Padina tetrastromatica and Turbinaria conoides) for its conversion to value added products. The result demonstrated that these extraction strategies had a significant impact on extraction yields, chemical characterization, monosaccharide composition, structural properties, microstructures, and biological activities of fucoidan. Subcritical water method produced a higher yield of fucoidan (~13 %) from both the biomass, with the sulfate content of fucoidan up to 33 %. Analysis of monosaccharide composition revealed that fucoidan contained the highest fucose (~83 %) and galactose (~30 %) contents with small amounts of arabinose, glucose, glucuronic acid, mannitol, mannose, rhamnose and xylose. Fucoidan extract contained polyphenolic (5.5 ± 0.6 mg GAE g−1) and flavonoid (3.2 ± 0.2 mg QE g−1) compounds and exhibited effective in vitro 2,2-diphenyl-1-picrylhydrazyl (1.3 ± 0.07 mg mL−1) as well as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (0.01 ± 0.0 mg mL−1) radical scavenging activities. By investigating the various outcomes, subcritical water technique was considered as the efficient and environmentally friendly approach for the extraction of fucoidan. Consequently, investigating the impact of extraction technologies on key structural components could aid multiple industries, including the nutraceutical, pharmaceutical, and cosmetics sectors, in gaining a better understanding of the benefits and drawbacks of various methods for upscale extraction. [Display omitted] • Extraction of fucoidan from macroalgae using traditional and greener techniques • Subcritical water extraction (SCWE) delivered the highest fucoidan yield (14 %). • Fucoidan isolated from the aqueous method contained highest sulfate content (25 %). • Fucoidan extracted using various methods mainly constituted of fucose and galactose. • Aqueous method extracted higher phenolics constituting higher antioxidant activity. [ABSTRACT FROM AUTHOR]

Sediment bacteria communities in shrimp pond are intricately linked to ecosystem function and the provision of services, such as nutrient cycling and excess nutrient metabolism in sediment. However, little is known about the main factor (assembly processes) governing abundant and rare bacterial diversity in land-based shrimp ponds. This study quantified the composition, spatial distribution, and assembly mechanisms of bacterial communities sampled from the sediment of 78 land-based shrimp ponds distributed along approximately 1700 km of the southeastern coastal zone of China. This was done using 16S rRNA gene amplicon sequencing. The bacterial community similarities decreased with spatial distance. Variation of bacterial community was mostly attributed to deterministic (environmental filtering) processes. Sediment sulfate concentrations regulated the balance between stochastic and deterministic bacterial community assembly processes, as indicated by the negative relationship between the stochasticity ratio, and network analysis highlighted increasingly sparse interconnections and less frequent co-occurrences among bacterial communities under greater sulfate concentrations. Our results demonstrate the negative impacts of sulfates associated with coastal aquaculture on sediment bacterial community dynamics, community assembly, and ecosystem function. • Sediment sulfate concentrations regulate balance between stochastic and deterministic bacterial community assembly processes. • Increasing sulfate concentration reduces network complexity or connectivity. • Sulfate content is an important environmental factor influencing bacterial richness [ABSTRACT FROM AUTHOR]

The present work aimed to evaluate the defense responses induced by chemically sulfated ulvans in Arabidopsis thaliana plants against the phytopathogenic fungi Alternaria brassicicola and Colletotrichum higginsianum . Derivatives with growing sulfate content (from 20.9 to 36.6%) were prepared with SO 3 -pyridine complex in formamide. NMR and FTIR spectroscopic analyses confirmed the increase of sulfate groups after the chemical sulfation process. The native sulfated polysaccharide (18.9% of sulfate) and its chemically sulfated derivatives similarly reduced the severity of both pathogenic fungi infections. Collectively, our results suggest that ulvans induce resistance against both fungal pathogens independently of its sulfation degree. [ABSTRACT FROM AUTHOR]

In the present work, bacterial cellulose nanocrystals (BCN) were prepared with three distinct sulfate contents, namely 0, 0.42 and 0.65 % OSO, by using HCl (BCN-HCl), a mixture of HCl and HSO (BCN-HCl/HSO) and HSO (BCN-HSO) as hydrolytic media, respectively. BCN were characterized by means of elemental analysis, X-ray diffraction, atomic force microscopy (AFM) and zeta potential measurements. All BCN samples had crystallinity indices of about 82 %, about 10 % higher than the original BC. The zeta potential values determined for BCN-HCl, BCN-HCl/HSO and BCN-HSO amounted to −(5 ± 1), −(40 ± 1) and −(46 ± 1) mV, respectively. The assembly between BCN-HCl, BCN-HCl/HSO or BCN-HSO and XG extracted from Tamarindus indica seeds was investigated by means of Freundlich isotherms, AFM, contact angle measurements, dynamic light scattering, ellipsometry and quartz crystal microbalance measurements. The adsorption experiments suggest that sulfate substitution on BCN surface as low as 0.65 % OSO impairs the original interaction with XG, thereby generating unstable layers with subsequent desorption. In contrast, the 0.42 % OSO samples presented favorable interactions with XG and exhibited highly improved colloidal stability compared to 0 % OSO samples. Films of XG adsorbed onto BCN with 0.42 % OSO were stable, homogeneous, and had low roughness and thickness. This is the first report showing that sulfate content on BCN surface can be tailored to promote high colloidal stability and sufficient interaction with XG. [ABSTRACT FROM AUTHOR]

Sulfur plays a vital role in the primary and secondary metabolism of plants, and carries an important function in a large number of different compounds. Despite this importance, compared to other mineral nutrients, relatively little is known about sulfur sensing and signalling, as well as about the mechanisms controlling sulfur metabolism and homeostasis. Sulfur contents in plants vary largely not only among different species, but also among accessions of the same species. We previously used associative transcriptomics to identify several genes potentially controlling variation in sulfate content in the leaves of Brassica napus , including an OASC gene for mitochondrial O-acetylserine thiollyase (OAS-TL), an enzyme involved in cysteine synthesis. Here, we show that loss of OASC in Arabidopsis thaliana lowers not only sulfate, but also glutathione levels in the leaves. The reduced accumulation is caused by lower sulfate uptake and translocation to the shoots; however, the flux through the pathway is not affected. In addition, we identified a single nucleotide polymorphism in the OASC gene among A. thaliana accessions that is linked to variation in sulfate content. Both genetic and transgenic complementation confirmed that the exchange of arginine at position 81 for lysine in numerous accessions resulted in a less active OASC and a lower sulfate content in the leaves. The mitochondrial isoform of OAS-TL is, thus, after the ATPS1 isoform of sulfurylase and the APR2 form of APS reductase 2, the next metabolic enzyme with a role in regulation of sulfate content in Arabidopsis.

This study aimed to evaluate and compare the quality of κ-carrageenan obtained from tissue-cultured and field-cultured Kappaphycus alvarezii. Carrageenan properties including yield, viscosity, gel strength and sulfate content were studied. After 60 days of cultivation, tissue-cultured K. alvarezii showed a higher growth rate (6.3 ± 0.01% day−1) than field-cultured seedlings (3.4 ± 0.3% day−1). The obtained carrageenan yield from tissue-cultured (67.3 ± 16.4%) was higher than field-cultured K. alvarezii (51.5 ± 21.0%). Gel viscosity of carrageenans from tissue-cultured K. alvarezii (1280.0 ± 25.0 cP) was found significantly higher than field-cultured samples (87.8 ± 20.9 cP). The 1.5% gel solution of tissue-cultured and field-cultured K. alvarezii exhibited gel strengths of 703.5 ± 14.1 and 288.3 ± 19.3 g cm−2, respectively. The average sulfate content of carrageenans was found to be significantly different between tissue-cultured and field-cultured K. alvarezii with 34.2 ± 10.9 and 7.5 ± 6.7%, respectively. Tissue culture is recommended to produce high quality seedlings by providing optimized culture conditions to the seaweed. This approach can serve as an alternative way to solve the seedling shortage problems currently faced by the seaweed industry. [ABSTRACT FROM AUTHOR]

BYF cements are a promising alternative to Portland cement due to their lower CO 2 emissions and energy demand. However, it is essential to assess how production parameters affect BYF clinker composition. In this study, clinkers with varying SO 3 content were synthesized at temperatures of 1100–1400 °C and retention times of 15–120 min. The mineralogy of the produced clinkers was analyzed using X-ray powder diffraction with Rietveld phase analysis. According to the results, firing temperatures of 1300–1350 °C, retention times of 30–60 min, and excess SO 3 are needed to obtain the desired clinker composition. It was proved that SO 3 contributed to the stabilization of β-C 2 S and the formation of ye'elimite. Additionally, increasing SO 3 resulted in higher contents of cubic ye'elimite relative to orthorhombic. It was demonstrated that the level of Fe 2 O 3 incorporated into C 4 A 3 $-c increased with the increase of SO 3, as indicated by the decrease in C 4 AF and unit cell volume. • BYF clinker composition was tested as a function of SO 3 , firing temperature, and time. • The influence of SO 3 on the polymorphism of belite and ye'elimite was assessed. • The formation of ye'elimite is controlled by firing temperature and SO 3 in raw meal. • Optimal firing temperature, SO 3 content and, retention time were determined. [ABSTRACT FROM AUTHOR]

The effects of ultra-high pressure (UHP, 100 MPa, 40, 24 h) processing and enzyme treatment on the physicochemical properties and anticoagulant activity of fucoidan obtained from Undaria pinnatifida sporophyll (UPS) were investigated. Crude UPS fucoidan (F) with an average MW of 877 kDa was slightly depolymerized by UHPassisted Tunicase treatment, yielding fucoidan with a lower MW (600-800 kDa). UHP-enzyme treatment decreased the sulfate, fucose and galactose contents of F but increased its glucose content. From FT-IR spectrum, UHP-enzyme treatment was found not to cause a structural change on S=O and C-O-S. After UHP-enzyme treatment, the sulfate content and average MW of F decreased with the increase of Tunicase concentration. It was found that among the UHP-enzyme-treated fucoidans, F-T0.3-U (Tunicase 0.3% treatment+UHP treatment) possessed the highest anticoagulant activity. F-T0.3-U appeared to inhibit blood coagulation via intrinsic pathway. With the increase of sulfate content in F, activated partial thromboplastin time (APTT) and thrombin time (TT) showed a tendency of increase. APTT and TT had the highest values in F-T0.3-U in which the sulfate concentration was 24%, but on the contrary decreased at a sulfate concentration of above 24%. This result indicates that there is an optimum sulfate concentration for the anticoagulant activity of fucoidan. Consequently, UHP-assisted enzymatic treatment was found to be helpful for the improvement of anticoagulant activities of fucoidan. [ABSTRACT FROM AUTHOR]

The effect of Na2SO4 concentrations from 0 to 17.6 mM in the nutrient solution of Lemna minor L. strain 6580 on adenosine 5'-phosphosulfate sulfotransferase activity was examined. Routinely, the plants were cultivated on 0.88 mM SO42-. The enzyme activity was increased by 50 to 100% after transfer to 0 or 0.0088 mM SO42-. Transfer back to 0.88 mM rapidly decreased the enzyme activity to the initial level. Cultivation on 17.6 mM Na2SO4 reduced extractable adenosine 5'-phosphosulfate sulfotransferase by 50%. The original level was rapidly re-established on 0.88 mM. In control experiments, a decrease in adenosine 5'-phosphosulfate sulfotransferase activity was also induced by K2SO4, whereas NaCl caused a small increase. This indicates that the observed effects are dependent on the sulfate ion. ATP-sulfurylase activity measured for comparison was only significantly affected by the omission of sulfate, which induced a 20% increase, indicating that this enzyme activity from Lemna minor is less susceptible to changes in medium sulfate than adenosine 5'-phosphosulfate sulfotransferase. A close relationship between adenosine 5'-phosphosulfate sulfotransferase activity and the content of asparagine, glutamine, non-protein thiols and sulfate in the tissue was detected, indicating a positive control mechanism induced by amides and a negative mechanism induced by thiols and sulfate. [ABSTRACT FROM AUTHOR]

The effect of SO2 on adenosine 5'-phosphosulfate sulfotransferase activity and various other parameters of needles from spruce (Picea abies L.) was studied using potted grafts in outdoor fumigation chambers and trees growing near a factory. In summer and autumn fumigation of grafted spruce, SO2 decreased the extractable activity of adenosine 5'-phosphosulfate sulfotransferase to 12-50% of the controls, and reduced the amount of 35S from sulphate incorporated into protein by excised branches to a comparable degree. SO2 treatment in January and February inhibited the increase in adenosine 5'-phosphosulfate sulfotransferase activity measured in the controls during this time. ATP-sulfurybse activity was less affected by SO2 fumigation. In trees growing near a factory with high SO2 emission, the activity of adenosine 5'- phusphosultate sutfotransferase was about 35% of that of trees from a control area. The low enzyme activity was correlated with a high content of sulfate and compounds containing thiol groups. [ABSTRACT FROM AUTHOR]

Describes a large extension project to this well-known hotel in Las Vegas, Nev. Includes discussion of the design concept and construction. Reviews the Investigation to determine the natural period of vibration for the hotel which Is In an area susceptible to earthquakes. Remedial measures needed due to faulty construction of one of the floors are also discussed. [ABSTRACT FROM AUTHOR]

• SCE method is a convenient, reliable and environmental friendly method. • SCE method can determine sulfate ion content in CSA cement based materials. • SCE method is improper for PO cement due to sulfate ion could be trapped by C-S-H. The penetration of sulfate ions into the concrete often causes durability problems such as spalling, cracking, and strength loss. Traditional methods for sulfates content test in cement-based materials, a large number of toxic and high-risk chemical reagents such as hydrochloric acid, barium chloride, barium chromate are used. In this research, the sodium carbonate extraction (SCE) method was used to determine the sulfates content in Ordinary Portland cement (OPC) and Calcium sulphoaluminate (CSA) cement while the gravimetric method was used as standard method to evaluate the accuracy of SCE method. The optimum SCE method operation conditions were determined as 0.30 mol/L sodium carbonate solution, liquid–solid ratio at 100:1 and particle size smaller than 500 μm. The results indicated that the replacement of gravimetric method with SCE method for sulfates content test is acceptable in CSA cement but improper for Portland cement system. Through the FTIR, XRD, and TG-DSC analysis, it was found that the absorption of sulfate ions by C-S-H gels was responsible for the failure of SCE method in Portland cement system. [ABSTRACT FROM AUTHOR]

Sulfated polysaccharides (SPs) from Gracilaria fisheri of Thailand, which were extracted in low-temperature (25 °C) water showed the highest content of phenolic compounds compared with those extracted at high temperature (55 °C). Crude SP antioxidant activity was evaluated by measuring the DPPH free radical scavenging effect which is directly related to the level of phenolic compounds. The sulfate content, total sugar, and SPs yield were also directly related to the extraction temperature. All extracts contained galactose as a major monosaccharide. High antioxidant activity of crude SP, positively correlated with the phenolic compound contents (R(2) = 0.996) contributed by the existence of sulfate groups and phenolic compounds. In purified SP, F1 fraction exhibited strong radical scavenging ability, but it was not significantly different compared to crude SP extracted at 25 °C. This indicated that the appropriate density and distribution of sulfate groups in the SP extract showed the best antioxidant activity.