RESUMEN
Dissimilatory sulfate reduction (DSR) mediated by sulfate-reducing microorganisms (SRMs) plays a pivotal role in global sulfur, carbon, oxygen, and iron cycles since at least 3.5 billion y ago. The canonical DSR pathway is believed to be sulfate reduction to sulfide. Herein, we report a DSR pathway in phylogenetically diverse SRMs through which zero-valent sulfur (ZVS) is directly generated. We identified that approximately 9% of sulfate reduction was directed toward ZVS with S8 as a predominant product, and the ratio of sulfate-to-ZVS could be changed with SRMs' growth conditions, particularly the medium salinity. Further coculturing experiments and metadata analyses revealed that DSR-derived ZVS supported the growth of various ZVS-metabolizing microorganisms, highlighting this pathway as an essential component of the sulfur biogeochemical cycle.
Asunto(s)
Sulfatos , Azufre , Sulfatos/metabolismo , Oxidación-Reducción , Azufre/metabolismo , Sulfuros/metabolismo , Óxidos de AzufreRESUMEN
BACKGROUND: Sulfate-reducing bacteria (SRB) drive the ocean sulfur and carbon cycling. They constitute a diverse phylogenetic and physiological group and are widely distributed in anoxic marine environments. From a physiological viewpoint, SRB's can be categorized as complete or incomplete oxidizers, meaning that they either oxidize their carbon substrate completely to CO2 or to a stoichiometric mix of CO2 and acetate. Members of Desulfofabaceae family are incomplete oxidizers, and within that family, Desulfofaba is the only genus with three isolates that are classified into three species. Previous physiological experiments revealed their capability of respiring oxygen. RESULTS: Here, we sequenced the genomes of three isolates in Desulfofaba genus and reported on a genomic comparison of the three species to reveal their metabolic potentials. Based on their genomic contents, they all could oxidize propionate to acetate and CO2. We confirmed their phylogenetic position as incomplete oxidizers based on dissimilatory sulfate reductase (DsrAB) phylogeny. We found the complete pathway for dissimilatory sulfate reduction, but also different key genes for nitrogen cycling, including nitrogen fixation, assimilatory nitrate/nitrite reduction, and hydroxylamine reduction to nitrous oxide. Their genomes also contain genes that allow them to cope with oxygen and oxidative stress. They have genes that encode for diverse central metabolisms for utilizing different substrates with the potential for more strains to be isolated in the future, yet their distribution is limited. CONCLUSIONS: Results based on marker gene search and curated metagenome assembled genomes search suggest a limited environmental distribution of this genus. Our results reveal a large metabolic versatility within the Desulfofaba genus which establishes their importance in biogeochemical cycling of carbon in their respective habitats, as well as in the support of the entire microbial community through releasing easily degraded organic matters.
Asunto(s)
Dióxido de Carbono , Sulfatos , Sulfatos/metabolismo , Filogenia , Dióxido de Carbono/metabolismo , Bacterias/genética , Genómica , Oxidación-Reducción , Carbono/metabolismoRESUMEN
3'-Phosphoadenosine-5'-phosphosulfate (PAPS) is the bioactive form of sulfate and is involved in all biological sulfation reactions. The enzymatic transformation method for PAPS is promising, but the low efficiency and high cost of enzyme purification and storage restrict its practical applications. Here, we reported PAPS biosynthesis with a protein crystalline inclusion (PCI)-based enzyme immobilization system. First, the in vivo crystalline inclusion protein CipA was identified as an efficient auto-assembly tag for immobilizing the bifunctional PAPS synthase (ASAK). After characterizing the pyrophosphokinase activity of a polyphosphate exonuclease PaPPX from Pseudomonas aeruginosa, and optimizing the linker fragment, auto-assembled enzymes ASAK-PT-CipA and PaPPX-PT-CipA were constructed. Then, the auto-assembled enzymes ASAK-PT-CipA and PaPPX-PT-CipA with high stability were co-expressed and immobilized for constructing a transformation system. The highest transformation rate of PAPS from ATP and sulfate reached 90%, and the immobilized enzyme can be reused 10 times. The present work provided a convenient, efficient, and easy to be enlarged auto-immobilization system for PAPS biosynthesis from ATP and sulfate. The immobilization system also represented a new approach to reduce the production cost of PAPS by facilitating the purification, storage, and reuse of related enzymes, and it would boost the studies on biotechnological production of glycosaminoglycans and sulfur-containing natural compounds.
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Enzimas Inmovilizadas , Sulfato Adenililtransferasa , Sulfato Adenililtransferasa/genética , Sulfato Adenililtransferasa/química , Sulfato Adenililtransferasa/metabolismo , Sulfatos/metabolismo , Fosfoadenosina Fosfosulfato/metabolismo , Adenosina Trifosfato/metabolismoRESUMEN
Iron oxides and sulfate are usually abundant in paddy soil, but their role in reducing methane emissions is little known. In this work, paddy soil was anaerobically cultivated with ferrihydrite and sulfate for 380 days. An activity assay, inhibition experiment, and microbial analysis were conducted to evaluate the microbial activity, possible pathways, and community structure, respectively. The results showed that anaerobic oxidation of methane (AOM) was active in the paddy soil. The AOM activity was much higher with ferrihydrite than sulfate, and an extra 10% of AOM activity was stimulated when ferrihydrite and sulfate coexisted. The microbial community was highly similar to the duplicates but totally different with different electron acceptors. The microbial abundance and diversity decreased due to the oligotrophic condition, but mcrA-carrying archaea increased 2-3 times after 380 days. Both the microbial community and the inhibition experiment implied that there was an intersection between iron and sulfur cycles. A "cryptic sulfur cycle" might link the two cycles, in which sulfate was quickly regenerated by iron oxides, and it might contribute 33% of AOM in the tested paddy soil. Complex links between methane, iron, and sulfur geochemical cycles occur in paddy soil, which may be significant in reducing methane emissions from rice fields.
Asunto(s)
Fertilizantes , Suelo , Metano/metabolismo , Sulfatos/metabolismo , Anaerobiosis , Archaea/metabolismo , Hierro/metabolismo , Oxidación-Reducción , Óxidos de Azufre , Azufre/metabolismoRESUMEN
A novel interdomain consortium composed of a methanogenic Archaeon and a sulfate-reducing bacterium was isolated from a microbial biofilm in an oil well in Cahuita National Park, Costa Rica. Both organisms can be grown in pure culture or as stable co-culture. The methanogenic cells were non-motile rods producing CH4 exclusively from H2/CO2. Cells of the sulfate-reducing partner were motile rods forming cell aggregates. They utilized hydrogen, lactate, formate, and pyruvate as electron donors. Electron acceptors were sulfate, thiosulfate, and sulfite. 16S rRNA sequencing revealed 99% gene sequence similarity of strain CaP3V-M-L2AT to Methanobacterium subterraneum and 98.5% of strain CaP3V-S-L1AT to Desulfomicrobium baculatum. Both strains grew from 20 to 42 °C, pH 5.0-7.5, and 0-4% NaCl. Based on our data, type strains CaP3V-M-L2AT (= DSM 113354 T = JCM 39174 T) and CaP3V-S-L1AT (= DSM 113299 T = JCM 39179 T) represent novel species which we name Methanobacterium cahuitense sp. nov. and Desulfomicrobium aggregans sp. nov.
Asunto(s)
Methanobacterium , Yacimiento de Petróleo y Gas , Methanobacterium/genética , Costa Rica , ARN Ribosómico 16S/genética , Sulfatos/metabolismo , Filogenia , ADN Bacteriano/genética , Análisis de Secuencia de ADN , Ácidos GrasosRESUMEN
Sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) inhabit oilfield production systems. Sulfur oxidation driven by SOB and dissimilatory sulfate reduction driven by SRB play important roles in sulfur cycle of oil reservoirs. More importantly, hydrogen sulfide produced by SRB is an acidic, flammable, and smelly toxic gas associated with reservoir souring, corrosion of oil-production facilities, and personnel safety. Effective control of SRB is urgently needed for the oil industry. This depends on an in-depth understanding of the microbial species that drive sulfur cycle and other related microorganisms in oil reservoir environments. Here, we identified SOB and SRB in produced brines of Qizhong block (Xinjiang Oilfield, China) from metagenome sequencing data based on reported SOB and SRB, reviewed metabolic pathways of sulfur oxidation and dissimilatory sulfate reduction, and ways for SRB control. The existing issues and future research of microbial sulfur cycle and SRB control are also discussed. Knowledge of the distribution of the microbial populations, their metabolic characteristics and interactions can help to develop an effective process to harness these microorganisms for oilfield production.
Asunto(s)
Desulfovibrio , Yacimiento de Petróleo y Gas , Oxidación-Reducción , Sulfatos/metabolismo , Desulfovibrio/metabolismo , Bacterias/genética , Bacterias/metabolismo , Azufre/metabolismoRESUMEN
A novel sulphate-reducing bacterium, strain SYKT, was isolated from a xenic culture of an anaerobic protist obtained from a sulphidogenic sediment of the saline Lake Hiruga in Fukui, Japan. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that SYKT clustered with the members of the genus Pseudodesulfovibrio. The closest relative of strain SYKT was Pseudodesulfovibrio sediminis SF6T, with 16S rRNA gene sequence identity of 97.43â%. Digital DNA-DNA hybridisation and average nucleotide identity values between SYKT and species of the genus Pseudodesulfovibrio fell below the respective thresholds for species delineation, indicating that SYKT represents a novel species of the genus Pseudodesulfovibrio. Cells measured 1.7-3.7×0.2-0.5 µm in size and were Gram-stain-negative, obligately anaerobic, motile by means of a single polar flagellum and had a curved rod or sigmoid shape. Cell growth was observed under saline conditions from pH 6.0 to 9.5 (optimum pH 8.0-9.0) and at a temperature of 10-30 °C (optimum 25 °C). SYKT used lactate, pyruvate, fumarate, formate and H2 as electron donors. It used sulphate, sulphite, thiosulphate and sulphur as terminal electron acceptors. Pyruvate and fumarate were fermented. Major cellular fatty acids were anteiso-C15â:â0, C16â:â0, anteiso-C17â:â1ω9c, summed feature 3 (C16â:â1ω6c and/or C16â:â1ω7c) and summed feature 8 (C18â:â1ω7c and/or C18â:â1ω6c). The DNA G+C content of SYKT was 49.4 mol%. On the basis of the the genetic and phenotypic features, SYKT was determined to represent a novel species of the genus Pseudodesulfovibrio for which the name Pseudodesulfovibrio nedwellii sp. nov. is proposed with type strain SYKT (=DSM 114958T=JCM 35746T).
Asunto(s)
ADN Bacteriano , Ácidos Grasos , Ácidos Grasos/química , Sedimentos Geológicos/microbiología , Sulfatos/metabolismo , Filogenia , ARN Ribosómico 16S/genética , Anaerobiosis , ADN Bacteriano/genética , Composición de Base , Técnicas de Tipificación Bacteriana , Análisis de Secuencia de ADN , Bacterias/genética , Desulfovibrionaceae , Piruvatos , Fosfolípidos/químicaRESUMEN
BACKGROUND: Lamellibrachia luymesi dominates cold sulfide-hydrocarbon seeps and is known for its ability to consume bacteria for energy. The symbiotic relationship between tubeworms and bacteria with particular adaptations to chemosynthetic environments has received attention. However, metabolic studies have primarily focused on the mechanisms and pathways of the bacterial symbionts, while studies on the animal hosts are limited. RESULTS: Here, we sequenced the transcriptome of L. luymesi and generated a transcriptomic database containing 79,464 transcript sequences. Based on GO and KEGG annotations, we identified transcripts related to sulfur metabolism, sterol biosynthesis, trehalose synthesis, and hydrolysis. Our in-depth analysis identified sulfation pathways in L. luymesi, and sulfate activation might be an important detoxification pathway for promoting sulfur cycling, reducing byproducts of sulfide metabolism, and converting sulfur compounds to sulfur-containing organics, which are essential for symbiotic survival. Moreover, sulfide can serve directly as a sulfur source for cysteine synthesis in L. luymesi. The existence of two pathways for cysteine synthesis might ensure its participation in the formation of proteins, heavy metal detoxification, and the sulfide-binding function of haemoglobin. Furthermore, our data suggested that cold-seep tubeworm is capable of de novo sterol biosynthesis, as well as incorporation and transformation of cycloartenol and lanosterol into unconventional sterols, and the critical enzyme involved in this process might have properties similar to those in the enzymes from plants or fungi. Finally, trehalose synthesis in L. luymesi occurs via the trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) pathways. The TPP gene has not been identified, whereas the TPS gene encodes a protein harbouring conserved TPS/OtsA and TPP/OtsB domains. The presence of multiple trehalases that catalyse trehalose hydrolysis could indicate the different roles of trehalase in cold-seep tubeworms. CONCLUSIONS: We elucidated several molecular pathways of sulfate activation, cysteine and cholesterol synthesis, and trehalose metabolism. Contrary to the previous analysis, two pathways for cysteine synthesis and the cycloartenol-C-24-methyltransferase gene were identified in animals for the first time. The present study provides new insights into particular adaptations to chemosynthetic environments in L. luymesi and can serve as the basis for future molecular studies on host-symbiont interactions and biological evolution.
Asunto(s)
Poliquetos , Trehalosa , Animales , Esteroles , Cisteína , Hidrocarburos , Azufre , Sulfuros/metabolismo , Sulfatos/metabolismoRESUMEN
Copper tolerance and SO2 tolerance are two well-studied phenotypic traits of Saccharomyces cerevisiae. The genetic bases of these traits are the allelic expansion at the CUP1 locus and reciprocal translocation at the SSU1 locus, respectively. Previous work identified a negative association between SO2 and copper tolerance in S. cerevisiae wine yeasts. Here we probe the relationship between SO2 and copper tolerance and show that an increase in CUP1 copy number does not always impart copper tolerance in S. cerevisiae wine yeast. Bulk-segregant QTL analysis was used to identify variance at SSU1 as a causative factor in copper sensitivity, which was verified by reciprocal hemizygosity analysis in a strain carrying 20 copies of CUP1. Transcriptional and proteomic analysis demonstrated that SSU1 over-expression did not suppress CUP1 transcription or constrain protein production and provided evidence that SSU1 over-expression induced sulfur limitation during exposure to copper. Finally, an SSU1 over-expressing strain exhibited increased sensitivity to moderately elevated copper concentrations in sulfur-limited medium, demonstrating that SSU1 over-expression burdens the sulfate assimilation pathway. Over-expression of MET 3/14/16, genes upstream of H2S production in the sulfate assimilation pathway increased the production of SO2 and H2S but did not improve copper sensitivity in an SSU1 over-expressing background. We conclude that copper and SO2 tolerance are conditional traits in S. cerevisiae and provide evidence of the metabolic basis for their mutual exclusivity. These findings suggest an evolutionary driver for the extreme amplification of CUP1 observed in some yeasts.
Asunto(s)
Proteínas de Saccharomyces cerevisiae , Vino , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Cobre/metabolismo , Dióxido de Azufre/análisis , Dióxido de Azufre/metabolismo , Proteómica , Vino/análisis , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Sulfatos/análisis , Sulfatos/metabolismo , Metalotioneína/genéticaRESUMEN
"Psychrodesulfovibrio", a proposed genus within the family Desulfovibrionaceae, is a group of sulfate-reducing bacteria with biogeochemical significance but restricted child taxa availability. In this study, a strictly anaerobic bacterium, designed strain FT415T, was isolated from mangrove sediments in Futian Mangrove Nature Reserve in Shenzhen, China. The strain was Gram-stain-negative, motile, and vibrio-shaped with a single polar flagellum, which grew at the temperature range of 15-42 °C (optimum 37 °C), pH range of 6.0-7.5 (optimum 6.8), and in the presence of 0-36 g l-1 NaCl (optimum 6 g l-1 NaCl). In the presence of sulfate, electron donors including lactate, ethanol, pyruvate, malate, fumarate, succinate, cysteine, and glycerol were incompletely oxidized to acetate, and H2 and formate were used as electron donors with acetate as the carbon source by strain FT415T. Sulfate, thiosulfate, sulfide, and anthraquinone-2,6-disulfonate were reduced in the presence of lactate. Fe(III) oxide was reduced without cell growth. Fermentative growth was observed with pyruvate and cysteine. Vitamins were not required for growth. The major cellular fatty acids (> 10%) were C16:0, summed feature 10 (C18:1 c11/t9/t6 and/or unknown ECL 17.834), C16:1 cis 9, and C18:0. The major polar lipids were phosphatidylethanolamine, phospholipids, and aminolipids. The predominant menaquinone was MK-6(H2). The genomic DNA G+C content was 56.7%. Phylogenetic analysis showed that strain FT415T shared a 98.1% similarity in 16S rRNA gene sequence, an average nucleotide identity value of 84.0%, an average amino-acid identity value of 85.4%, and a digital DNA-DNA hybridization value of 25.7% with its closest relative Desulfovibrio subterraneus HN2T, which has been proposed to be transferred to the genus "Psychrodesulfovibrio". Based on phenotypic, phylogenetic, and genotypic evidence, a new species of the family Desulfovibrionaceae, Desulfovibrio mangrovi sp. nov. was proposed with the type strain FT415T (=GDMCC 1.3410T=KCTC 25525T).
Asunto(s)
Desulfovibrio , Sulfatos , Humanos , Niño , Sulfatos/análisis , Sulfatos/metabolismo , Filogenia , ARN Ribosómico 16S/genética , Composición de Base , Cisteína/genética , Cloruro de Sodio , Compuestos Férricos , Análisis de Secuencia de ADN , Ácidos Grasos/análisis , Fosfolípidos/análisis , Lactatos , Piruvatos , ADN Bacteriano/genética , ADN Bacteriano/química , Técnicas de Tipificación Bacteriana , Sedimentos Geológicos/microbiologíaRESUMEN
BACKGROUND: Calcific aortic stenosis (CAS) is more prevalent, occurs earlier, progresses faster and has worse outcomes in patients with chronic kidney disease (CKD). The uremic toxin indoxyl sulfate (IS) is powerful predictor of cardiovascular mortality in these patients and a strong promoter of ectopic calcification whose role in CAS remains poorly studied. The objective of this study was to evaluate whether IS influences the mineralization of primary human valvular interstitial cells (hVICs) from the aortic valve. METHODS: Primary hVICs were exposed to increasing concentrations of IS in osteogenic medium (OM). The hVICs' osteogenic transition was monitored by qRT-PCRs for BMP2 and RUNX2 mRNA. Cell mineralization was assayed using the o-cresolphthalein complexone method. Inflammation was assessed by monitoring NF-κB activation using Western blots as well as IL-1ß, IL-6 and TNF-α secretion by ELISAs. Small interfering RNA (siRNA) approaches enabled us to determine which signaling pathways were involved. RESULTS: Indoxyl-sulfate increased OM-induced hVICs osteogenic transition and calcification in a concentration-dependent manner. This effect was blocked by silencing the receptor for IS (the aryl hydrocarbon receptor, AhR). Exposure to IS promoted p65 phosphorylation, the blockade of which inhibited IS-induced mineralization. Exposure to IS promoted IL-6 secretion by hVICs, a phenomenon blocked by silencing AhR or p65. Incubation with an anti-IL-6 antibody neutralized IS's pro-calcific effects. CONCLUSION: IS promotes hVIC mineralization through AhR-dependent activation of the NF-κB pathway and the subsequent release of IL-6. Further research should seek to determine whether targeting inflammatory pathways can reduce the onset and progression of CKD-related CAS.
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Estenosis de la Válvula Aórtica , Calcinosis , Humanos , Válvula Aórtica/metabolismo , FN-kappa B/metabolismo , Estenosis de la Válvula Aórtica/metabolismo , Interleucina-6/farmacología , Indicán/farmacología , Indicán/metabolismo , Osteogénesis , Receptores de Hidrocarburo de Aril/metabolismo , Calcinosis/metabolismo , Células Cultivadas , Diferenciación Celular , ARN Interferente Pequeño/metabolismo , Sulfatos/metabolismo , Sulfatos/farmacologíaRESUMEN
Nanoplastic contamination is an emerging environmental concern worldwide. In particular, sulfate anionic surfactants often appear along with nanosized plastic particles in personal care products, suggesting that sulfate-modified nanosized polystyrene (S-NP) may occur, remain, and spread into the environment. However, whether S-NP adversely affects learning and memory is unknown. In this study, we used a positive butanone training protocol to evaluate the effects of S-NP exposure on short-term associative memory (STAM) and long-term associative memory (LTAM) in Caenorhabditis elegans. We observed that long-term S-NP exposure impairs both STAM and LTAM in C. elegans. We also observed that mutations in the glr-1, nmr-1, acy-1, unc-43, and crh-1 genes eliminated the STAM and LTAM impairment induced by S-NP, and the mRNA levels of these genes were also decreased upon S-NP exposure. These genes encode ionotropic glutamate receptors (iGluRs), cyclic adenosine monophosphate (cAMP)/Ca2+ signaling proteins, and cAMP-response element binding protein (CREB)/CRH-1 signaling proteins. Moreover, S-NP exposure inhibited the expression of the CREB-dependent LTAM genes nid-1, ptr-15, and unc-86. Our findings provide new insights into long-term S-NP exposure and the impairment of STAM and LTAM, which involve the highly conserved iGluRs and CRH-1/CREB signaling pathways.
Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animales , Caenorhabditis elegans/fisiología , Poliestirenos/toxicidad , Poliestirenos/metabolismo , Receptores Ionotrópicos de Glutamato/genética , Receptores Ionotrópicos de Glutamato/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Sulfatos/metabolismo , Elementos de Respuesta , Factores de Transcripción/metabolismoRESUMEN
Sulfate-reducing bacteria (SRB) are essential functional microbial taxa for degrading organic matter (OM) in anoxic marine environments. However, there are little experimental data regarding how SRB regulates microbial communities. Here, we applied a top-down microbial community management approach by inhibiting SRB to elucidate their contributions to the microbial community during OM degradation. Based on the highly replicated microcosms (n = 20) of five different incubation stages, we found that many microbial community properties were influenced after inhibiting SRB, including the composition, structure, network, and community assembly processes. We also found a strong coexistence pattern between SRB and other abundant phylogenetic lineages via positive frequency-dependent selection. The relative abundances of the families Synergistaceae, Peptostreptococcaceae, Dethiosulfatibacteraceae, Prolixibacteraceae, Marinilabiliaceae, and Marinifilaceae were simultaneously suppressed after inhibiting SRB during OM degradation. A close association between SRB and the order Marinilabiliales among coexisting taxa was most prominent. They contributed to preserved modules during network successions, were keystone nodes mediating the networked community, and contributed to homogeneous ecological selection. The molybdate tolerance test of the isolated strains of Marinilabiliales showed that inhibited SRB (not the inhibitor of SRB itself) triggered a decrease in the relative abundance of Marinilabiliales. We also found that inhibiting SRB resulted in reduced pH, which is unsuitable for the growth of most Marinilabiliales strains, while the addition of pH buffer (HEPES) in SRB-inhibited treatment microcosms restored the pH and the relative abundances of these bacteria. These data supported that SRB could modify niches to affect species coexistence. IMPORTANCE Our model offers insight into the ecological properties of SRB and identifies a previously undocumented dimension of OM degradation. This targeted inhibition approach could provide a novel framework for illustrating how functional microbial taxa associate the composition and structure of the microbial community, molecular ecological network, and community assembly processes. These findings emphasize the importance of SRB during OM degradation. Our results proved the feasibility of the proposed study framework, inhibiting functional taxa at the community level, for illustrating when and to what extent functional taxa can contribute to ecosystem services.
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Bacterias , Microbiota , Humanos , Filogenia , Bacteroidetes/metabolismo , Sedimentos Geológicos/microbiología , Sulfatos/metabolismoRESUMEN
To determine how potassium nitrate (KNO3) effect apple roots and sulfate assimilation in the presence of wood biochar in soil, KNO3 was applied to the root-zone soil without or with 150-day naturally aged wood biochar (1% w/w) in soil. Soil properties, root architecture, root activity, the accumulation and distribution of sulfur (S), enzyme activity, and gene expression related to sulfate uptake and assimilation in apple trees were analyzed. Results showed that KNO3 and wood biochar application exhibited synergistic effects on improving S accumulation and root growth. Meanwhile, KNO3 application increased the activities of ATPS, APR, SAT, OASTL and upregulated the expression of ATPS, APR, Sultr3;1, Sultr2;1, Sultr3;4, and Sultr3;5 in both roots and leaves, and the positive effects of KNO3 addition on both genes and enzyme activity were enhanced by wood biochar. Wood biochar amendment alone promoted the activities of enzymes described above, upregulated the expression of ATPS, APR, Sultr3;1, Sultr2;1, Sultr3;4, and Sultr4;2 in leaves, and enhanced S distribution in roots. KNO3 addition alone decreased S distribution in roots and increased that in stems. In the presence of wood biochar in soil, KNO3 application decreased S distribution in roots but increased that in both stems and leaves. These results indicated that the wood biochar in soil enhances the effect of KNO3 on S accumulation by promoting root growth and sulfate assimilation in apple trees.
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Malus , Contaminantes del Suelo , Suelo , Malus/metabolismo , Madera/metabolismo , Carbón Orgánico/farmacología , Azufre , Sulfatos/metabolismo , Contaminantes del Suelo/metabolismoRESUMEN
Selenium (Se) is an essential micronutrient of fundamental importance to human health and the main Se source is from plant-derived foods. Plants mainly take up Se as selenate (SeO42-), through the root sulfate transport system, because of their chemical similarity. The aims of this study were (1) to characterize the interaction between Se and S during the root uptake process, by measuring the expression of genes coding for high-affinity sulfate transporters and (2) to explore the possibility of increasing plant capability to take up Se by modulating S availability in the growth medium. We selected different tetraploid wheat genotypes as model plants, including a modern genotype, Svevo (Triticum turgidum ssp. durum), and three ancient Khorasan wheats, Kamut, Turanicum 21, and Etrusco (Triticum turgidum ssp. turanicum). The plants were cultivated hydroponically for 20 days in the presence of two sulfate levels, adequate (S = 1.2 mM) and limiting (L = 0.06 mM), and three selenate levels (0, 10, 50 µM). Our findings clearly showed the differential expression of genes encoding the two high-affinity transporters (TdSultr1.1 and TdSultr1.3), which are involved in the primary uptake of sulfate from the rhizosphere. Interestingly, Se accumulation in shoots was higher when S was limited in the nutrient solution.
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Selenio , Triticum , Humanos , Ácido Selénico , Triticum/metabolismo , Tetraploidía , Sulfatos/metabolismo , Selenio/metabolismo , GenotipoRESUMEN
Trace mineral (TM) source can potentially alter nutrient digestibility through effects on microbial populations. A meta-analysis was conducted to determine whether sulfate versus hydroxy (IntelliBond) sources of supplemental Cu, Zn, and Mn had any effect on dry matter intake (DMI), dry matter digestibility, and neutral detergent fiber (NDF) digestibility. All available cattle studies (8 studies, 12 comparisons) were used to estimate the effect size (hydroxy mean - sulfate mean). Factors included in the analysis were method of digestibility analysis (total collection, marker-based, or 24 h in situ), study design (randomized design or Latin square), beef (n = 5) versus dairy (n = 7) cattle, and days on treatment; these factors were retained when P < 0.05. Dry matter digestibility was increased by hydroxy TM in beef (1.64 ± 0.35 units) but not in dairy models (0.16 ± 0.13 units) relative to sulfate TM. The NDF digestibility increased significantly with hydroxy versus sulfate TM, but digestibility assessment method influenced this response. Studies using total collection or undigested NDF as a flow marker showed a significant increase (2.68 ± 0.40 units and 1.08 ± 0.31 units, respectively) in NDF digestibility for hydroxy versus sulfate TM; but studies utilizing 24-h in situ incubation did not detect any change (-0.03 ± 0.23 units). These observations may reveal differences in precision of measurement or may indicate mineral effects beyond the rumen; total collection is considered the gold standard method. Hydroxy TM did not affect DMI per animal or per unit of body weight relative to sulfate TM. In conclusion, feeding hydroxy versus sulfate TM does not appear to affect DMI but, depending on type of cattle and method of measurement, can increase dry matter digestibility and NDF digestibility, which may be explained by differences in solubility of the TM sources in rumen, differentially affecting fermentation.
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Oligoelementos , Bovinos , Animales , Femenino , Oligoelementos/farmacología , Sulfatos/metabolismo , Sulfatos/farmacología , Dieta/veterinaria , Fibras de la Dieta/metabolismo , Digestión , Nutrientes , Rumen/metabolismo , Fermentación , Alimentación Animal , LactanciaRESUMEN
Stem cell therapy is a promising strategy for cartilage tissue engineering, and cell transplantation using polymeric scaffolds has recently gained attention. Herein, we encapsulated human adipose-derived stem cells (hASCs) within the alginate sulfate hydrogel and then added them to polycaprolactone/gelatin electrospun nanofibers and extracellular matrix (ECM) powders to mimic the cartilage structure and characteristic. The composite hydrogel scaffolds were developed to evaluate the relevant factors and conditions in mechanical properties, cell proliferation, and differentiation to enhance cartilage regeneration. For this purpose, different concentrations (1-5 % w/v) of ECM powder were initially loaded within an alginate sulfate solution to optimize the best composition for encapsulated hASCs viability. Adding 4 % w/v of ECM resulted in optimal mechanical and rheological properties and better cell viability. In the next step, electrospun nanofibrous layers were added to the alginate sulfate/ECM composite to prepare different layered hydrogel-nanofiber (2, 3, and 5-layer) structures with the ability to mimic the cartilage structure and function. The 3-layer structure was selected as the optimum layered composite scaffold, considering cell viability, mechanical properties, swelling, and biodegradation behavior; moreover, the chondrogenesis potential was assessed, and the results showed promising features for cartilage tissue engineering application.
Asunto(s)
Nanofibras , Ingeniería de Tejidos , Humanos , Ingeniería de Tejidos/métodos , Nanofibras/química , Andamios del Tejido/química , Hidrogeles/química , Alginatos/metabolismo , Sulfatos/metabolismo , Cartílago , Matriz Extracelular/metabolismo , Células MadreRESUMEN
Kaposi's sarcoma-associated herpesvirus (KSHV) causes primary effusion lymphoma (PEL). PEL cell lines require expression of the cellular FLICE inhibitory protein (cFLIP) for survival, although KSHV encodes a viral homolog of this protein (vFLIP). Cellular and viral FLIP proteins have several functions, including, most importantly, the inhibition of pro-apoptotic caspase 8 and modulation of NF-κB signaling. To investigate the essential role of cFLIP and its potential redundancy with vFLIP in PEL cells, we first performed rescue experiments with human or viral FLIP proteins known to affect FLIP target pathways differently. The long and short isoforms of cFLIP and molluscum contagiosum virus MC159L, which are all strong caspase 8 inhibitors, efficiently rescued the loss of endogenous cFLIP activity in PEL cells. KSHV vFLIP was unable to fully rescue the loss of endogenous cFLIP and is therefore functionally distinct. Next, we employed genome-wide CRISPR/Cas9 synthetic rescue screens to identify loss of function perturbations that can compensate for cFLIP knockout. Results from these screens and our validation experiments implicate the canonical cFLIP target caspase 8 and TRAIL receptor 1 (TRAIL-R1 or TNFRSF10A) in promoting constitutive death signaling in PEL cells. However, this process was independent of TRAIL receptor 2 or TRAIL, the latter of which is not detectable in PEL cell cultures. The requirement for cFLIP is also overcome by inactivation of the ER/Golgi resident chondroitin sulfate proteoglycan synthesis and UFMylation pathways, Jagunal homolog 1 (JAGN1) or CXCR4. UFMylation and JAGN1, but not chondroitin sulfate proteoglycan synthesis or CXCR4, contribute to TRAIL-R1 expression. In sum, our work shows that cFLIP is required in PEL cells to inhibit ligand-independent TRAIL-R1 cell death signaling downstream of a complex set of ER/Golgi-associated processes that have not previously been implicated in cFLIP or TRAIL-R1 function.
Asunto(s)
Apoptosis , Herpesvirus Humano 8 , Humanos , Apoptosis/genética , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/genética , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/metabolismo , Caspasa 8/genética , Caspasa 8/metabolismo , Muerte Celular , Herpesvirus Humano 8/metabolismo , Ligandos , Proteínas de la Membrana/metabolismo , Proteoglicanos/metabolismo , Sulfatos/metabolismoRESUMEN
Cholangiocytes exhibit morphological and functional heterogeneity, depending on their anatomical localization; however, like other ductal organs, their mucosal surface is covered with mucin, which functions to prevent the entry of foreign substances, lubricate and prevent clogging by bile. Recently, the authors discovered that distinct sulfated glycans recognized by a series of antisulfated glycan antibodies are expressed not only in normal intrahepatic bile ducts but also in intrahepatic cholangiocarcinoma (iCCA). In this review, the authors first describe the anatomy of bile ducts and the biochemical characteristics of bile-duct-associated mucins, and then describe differences in structure and expression patterns of these sulfated glycans in physiological and pathological conditions. Finally, potential therapeutic strategies for iCCA using antisulfated glycan antibodies are discussed.
Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , Humanos , Sulfatos/metabolismo , Colangiocarcinoma/patología , Conductos Biliares Intrahepáticos/metabolismo , Conductos Biliares Intrahepáticos/patología , Mucinas/metabolismo , Neoplasias de los Conductos Biliares/patología , PolisacáridosRESUMEN
Complex interactions exist among microorganisms in a community to carry out ecological processes and adapt to changing environments. Here, we constructed a quad-culture consisting of a cellulolytic bacterium (Ruminiclostridium cellulolyticum), a hydrogenotrophic methanogen (Methanospirillum hungatei), an acetoclastic methanogen (Methanosaeta concilii), and a sulfate-reducing bacterium (Desulfovibrio vulgaris). The four microorganisms in the quad-culture cooperated via cross-feeding to produce methane using cellulose as the only carbon source and electron donor. The community metabolism of the quad-culture was compared with those of the R. cellulolyticum-containing tri-cultures, bi-cultures, and mono-culture. Methane production was higher in the quad-culture than the sum of the increases in the tri-cultures, which was attributed to a positive synergy of four species. In contrast, cellulose degradation by the quad-culture was lower than the additive effects of the tri-cultures which represented a negative synergy. The community metabolism of the quad-culture was compared between a control condition and a treatment condition with sulfate addition using metaproteomics and metabolic profiling. Sulfate addition enhanced sulfate reduction and decreased methane and CO2 productions. The cross-feeding fluxes in the quad-culture in the two conditions were modeled using a community stoichiometric model. Sulfate addition strengthened metabolic handoffs from R. cellulolyticum to M. concilii and D. vulgaris and intensified substrate competition between M. hungatei and D. vulgaris. Overall, this study uncovered emergent properties of higher-order microbial interactions using a four-species synthetic community. IMPORTANCE A synthetic community was designed using four microbial species that together performed distinct key metabolic processes in the anaerobic degradation of cellulose to methane and CO2. The microorganisms exhibited expected interactions, such as cross-feeding of acetate from a cellulolytic bacterium to an acetoclastic methanogen and competition of H2 between a sulfate reducing bacterium and a hydrogenotrophic methanogen. This validated our rational design of the interactions between microorganisms based on their metabolic roles. More interestingly, we also found positive and negative synergies as emergent properties of high-order microbial interactions among three or more microorganisms in cocultures. These microbial interactions can be quantitatively measured by adding and removing specific members. A community stoichiometric model was constructed to represent the fluxes in the community metabolic network. This study paved the way toward a more predictive understanding of the impact of environmental perturbations on microbial interactions sustaining geochemically significant processes in natural systems.
