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Journal of Environmental Management Feb 2024During the long-term stabilization process of landfills, the pressure field undergoes constant changes. This study constructed dynamic pressure changes scenarios of...
During the long-term stabilization process of landfills, the pressure field undergoes constant changes. This study constructed dynamic pressure changes scenarios of high-pressure differentials (0.6 MPa) and low-pressure differentials (0.2 MPa) in the landfill pressure field at 25 °C and 50 °C, and investigated the sulfate reduction behavior in response to landfill dynamic pressure changes. The results showed that the pressurization or depressurization of high-pressure differentials caused more significant differences in sulfate reduction behavior than that of low-pressure differentials. The lowest hydrogen sulfide (HS) release peak concentration under pressurization was only 29.67% of that under initial pressure condition; under depressurization, the highest peak concentration of HS was up to 21,828 mg m, posing a serious risk of HS pollution. Microbial community and correlation analysis showed that pressure had a negative impact on the sulfate-reducing bacteria (SRB) community, and the SRB community adjusted its structure to adapt to pressure changes. Specific SRBs were further enriched with pressure changes. Differential HS release behavior under pressure changes in the 25 °C pressure environments were mediated by Desulfofarcimen (ASV343) and Desulfosporosinus (ASV1336), while Candidatus Desulforudis (ASV24) and Desulfohalotomaculum (ASV94) played a key role at 50 °C. This study is helpful in the formulation of control strategies for the source of odor pollution in landfills.
Topics: Hydrogen Sulfide; Desulfovibrio; Waste Disposal Facilities; Sulfates
PubMed: 38081091
DOI: 10.1016/j.jenvman.2023.119784 -
Biofouling 2023Sulphate-reducing bacteria (SRB) are known to cause severe corrosion of steel structures in various industries, resulting in significant economic and environmental... (Review)
Review
Sulphate-reducing bacteria (SRB) are known to cause severe corrosion of steel structures in various industries, resulting in significant economic and environmental consequences. This review paper critically examines the impact of SRB-induced corrosion on steel, including the formation of SRB biofilms, the effect on different types of steel, and the various models developed to investigate this phenomenon. The role of environmental factors in SRB-induced corrosion, molecular techniques for studying SRBs, and strategies for mitigating corrosion are discussed. Additionally, the sustainability implications of SRB-induced corrosion and the potential use of alternative materials were explored. By examining the current state of knowledge on this topic, this review aims to provide a comprehensive understanding of the impact of SRB-induced corrosion on steel and identify opportunities for further research and development.
Topics: Biofilms; Steel; Corrosion; Desulfovibrio; Sulfates
PubMed: 38073525
DOI: 10.1080/08927014.2023.2284316 -
Journal of Hazardous Materials Mar 2024The sulfate-reducing efficiency of sulfate-reducing bacteria (SRB) is strongly influenced by the presence of oxygen, but little is known about the oxygen tolerance...
The sulfate-reducing efficiency of sulfate-reducing bacteria (SRB) is strongly influenced by the presence of oxygen, but little is known about the oxygen tolerance mechanism of SRB and the effect of oxygen on the metalliferous immobilization by SRB. The performance evaluation, identification of bioprecipitates, and microbial and metabolic process analyses were used here to investigate the As immobilization mechanisms and survival strategies of the SRB1 consortium under different oxygen-containing environments. Results indicated that the sulfate reduction efficiency was significantly decreased under aerobic (47.37%) compared with anaerobic conditions (66.72%). SEM analysis showed that under anaerobic and aerobic conditions, the morphologies of mineral particles were different, whereas XRD and XPS analyses showed that the most of As bioprecipitates under both conditions were arsenic minerals such as AsS and AsS. The abundances of Clostridium_sensu_stricto_1, Desulfovibrio, and Thiomonas anaerobic bacteria were significantly higher under anaerobic than aerobic conditions, whereas the aerobic Pseudomonas showed an opposite trend. Network analysis revealed that Desulfovibrio was positively correlated with Pseudomonas. Metabolic process analysis confirmed that under aerobic conditions the SRB1 consortium generated additional extracellular polymeric substances (rich in functionalities such as Fe-O, SO, CO, and -OH) and the anti-oxidative enzyme superoxide dismutase to resist As stress and oxygen toxicity. New insights are provided here into the oxygen tolerance and detoxification mechanism of SRB and provide a basis for the future remediation of heavy metal(loid)-contaminated environments.
Topics: Microbial Consortia; Anaerobiosis; Desulfovibrio; Sulfates; Oxygen
PubMed: 38056257
DOI: 10.1016/j.jhazmat.2023.133052 -
Revista Espanola de Quimioterapia :... Feb 2024
Topics: Humans; Abscess; Desulfovibrio desulfuricans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Anti-Bacterial Agents; Actinobacteria
PubMed: 38050695
DOI: 10.37201/req/081.2023 -
Food & Function Dec 2023Food allergy (FA) has become a prominent problem in public health. 2'-Fucosyllactose (2'-FL) was reported to alleviate FA symptoms; however, the regulatory mechanism is...
Food allergy (FA) has become a prominent problem in public health. 2'-Fucosyllactose (2'-FL) was reported to alleviate FA symptoms; however, the regulatory mechanism is still unclear. This study evaluated the 2'-FL antiallergic potential in an ovalbumin (OVA)-sensitized mouse model and explored the systemic effects of 2'-FL on gut microecology and the intestinal immune barrier. The results showed that 2'-FL alleviated allergy symptoms, decreased serum allergic indicator levels, enhanced the intestinal barrier, and attenuated low-grade inflammation. The up-regulation of G protein-coupled receptors (GPRs) was associated with higher levels of short-chain fatty acids (SCFAs) in 2'-FL intervention mice. 2'-FL also improved the intestinal microbiota diversity and increased the abundance of , , and while suppressing , , and . Additionally, 2'-FL ameliorated the imbalance of Th2/Th1, mainly by decreasing Th2-type immune response and enhanced CD4 + Foxp3 + Treg immunoreaction. These results suggest that 2'-FL restores intestinal barrier defects, gut microbiota disorder, and immune impairment while alleviating ovalbumin-induced allergic symptoms in FA mice.
Topics: Mice; Animals; Ovalbumin; Food Hypersensitivity; Trisaccharides; Mice, Inbred BALB C; Disease Models, Animal; Cytokines
PubMed: 38009336
DOI: 10.1039/d3fo03272h -
Microbial Pathogenesis Dec 2023Chronodisruption, commonly displayed by people living with obesity (PLO), is linked to colonic microbiota dysbiosis, and may increase the risk of many chronic...
Chronodisruption, commonly displayed by people living with obesity (PLO), is linked to colonic microbiota dysbiosis, and may increase the risk of many chronic non-communicable diseases, whereas dietary interventions-called chrononutrition may mitigate it. We evaluated the in vitro effects of spent coffee grounds (SCG), and their antioxidant dietary fiber (SCG-DF) on the colonic microbiota of an obese donor displaying dysbiosis and chronodisruption. Basal microbiota pattern was associated with an increased risk of non-communicable chronic diseases. Both samples decrease species richness and increase microbiota diversity (p < 0.05; Chao and Shannon index, respectively), positively enhancing Firmicutes/Bacteroidetes index (SCG, p < 0.04; SCG-DF, p < 0.02). SCG and SCG-DF modulated the microbiota, but SCG-DF induced greater changes, significantly increasing. p_Actonobacterias (SCG p < 0.04; SCG-DF, p < 0.02), and reducing g_Alistipes; s_putredinis, g_Prevotella;s_copri. The highest increase was displayed by p_Proteobacteria (f_Desulfovibrionaceae and f_Alcanigenaceae, p < 0.05), while g_Haemophilus; s_parainfluenzae decreased (p < 0.05). However, neither SCG nor SCG-DF modulated g_Alistipes (evening-type colonic microbial marker) beneficially. SCG and SCG-DF reduced (p < 0.05) g_Lachnospira, a microbial evening-type marker, among other microbial populations, of an obese donor displaying chronodisruption and dysbiosis. SCG and SCG-DF displayed a prebiotic effect with the potential to mitigate diseases linked to chronodisruption.
Topics: Humans; Coffee; Antioxidants; Dysbiosis; Dietary Fiber; Obesity
PubMed: 37984489
DOI: 10.1016/j.micpath.2023.106431 -
Journal of Ethnopharmacology Feb 2024Persicaria hydropiper (L.) Spach, a herb that is prevalent across Asia and Europe, finds utility as both a culinary ingredient and medicinal herb. In China, P....
A neutral polysaccharide from Persicaria hydropiper (L.) Spach ameliorates lipopolysaccharide-induced intestinal barrier injury via regulating the gut microbiota and modulating AKT/PI3K/mTOR and MAPK signaling pathways.
ETHNOPHARMACOLOGICAL RELEVANCE
Persicaria hydropiper (L.) Spach, a herb that is prevalent across Asia and Europe, finds utility as both a culinary ingredient and medicinal herb. In China, P. hydropiper decoction is commonly employed to alleviate dysentery, gastroenteritis, and diarrhea symptoms.
AIM OF THE STUDY
To assess the effects of a neutral polysaccharide from P. hydropiper (PHP) on the intestinal barrier (IB) injury induced by lipopolysaccharide (LPS) in mice, and elucidate the molecular mechanisms involved.
MATERIALS AND METHODS
PHP was extracted from dried P. hydropiper herb using hot water extraction, followed by ethanol precipitation. The extract underwent successive isolation and purification steps involving anion-exchange and gel filtration chromatography. The primary structure of PHP was determined using Fourier-transformed infrared spectroscopy, ion chromatography, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. Male BALB/c mice were randomly assigned to control (CON), model (MOD), berberine hydrochloride (BBR), and PHP (20, 40 and 80 mg/kg) groups. Histopathological changes in jejunal tissues were assessed through hematoxylin and eosin (HE) staining. The expression levels of proteins and genes involved in AKT/PI3K/mTOR and MAPK signaling pathways were evaluated using qRT-PCR and Western blotting, respectively. The composition and abundance of the gut microbiota in mice were analyzed using high-throughput 16S rRNA gene sequencing. Additionally, the concentrations of short-chain fatty acids (SCFAs) were determined using GC-MS.
RESULTS
The main components of PHP included arabinose, galactose, and glucose (molar ratio = 1.00:5.52:11.39). The backbone of PHP consisted of →4)-Glcp-(1→, →4,6)-Glcp-(1→, →4)-Galp-(1→, →4,6)-Galp-(1→. The branched chains primarily consisted of 5)-Araf-(1→ residues, which were attached to the backbone through →6)-Glcp-(1→ and →6)-Galp-(1→ at the 6-position. Histological analysis demonstrated that PHP exhibited a mitigating effect on intestinal damage induced by LPS. PHP could markedly reduce the mRNA levels of PI3K, AKT, mTOR, p70 S6K, Ras, Raf1, MEK1/2, p38, ERK1/2, and JNK, while downregulating the protein levels of p-mTOR, p-PI3K, p-AKT, p-p38, p-ERK, and p-JNK. PHP also modulated the diversities and abundances of the gut microbiota, resulting in an increase in the abundances of Lactobacillaceae, Anaerovoracaceae, Lachnospiraceae, Eggerthellaceae, and Desulfovibrionaceae and a decrease in the abundances of Muribaculaceae, Prevotellaceae, and Rikenellaceae. Additionally, PHP significantly increased the content of various SCFAs.
CONCLUSION
PHP emerges as a pivotal factor in the repair of IB injury by virtue of its ability to regulate the gut microbiota, elevate SCFA levels, and inhibit the MAPK and AKT/PI3K/mTOR pathways. It is worth noting that the therapeutic effect of high-dose PHP was remarkably significant, surpassing even the positive control of berberine hydrochloride.
Topics: Male; Mice; Animals; Lipopolysaccharides; Proto-Oncogene Proteins c-akt; MAP Kinase Signaling System; Phosphatidylinositol 3-Kinases; Gastrointestinal Microbiome; Berberine; RNA, Ribosomal, 16S; TOR Serine-Threonine Kinases; Polysaccharides; Fatty Acids, Volatile
PubMed: 37952732
DOI: 10.1016/j.jep.2023.117403 -
Journal of Hazardous Materials Feb 2024It is well-known that several Chinese patent medicines use realgar as a specific component. People are more aware of the health dangers associated with realgar since it...
Study on arsenic speciation, bioaccessibility, and gut microbiota in realgar-containing medicines by DGT technique and artificial gastrointestinal extraction (PBET) combine with simulated human intestinal microbial ecosystem (SHIME).
It is well-known that several Chinese patent medicines use realgar as a specific component. People are more aware of the health dangers associated with realgar since it includes arsenic. Previous research overstated the arsenic toxicity of realgar-containing Chinese prescription medications because little thought was given to the influence of arsenic bioaccessibility by gut microbiota. In light of this, this study examined the total content, bioaccessibility and speciation of targeted medications while also examining intestinal epithelial transit utilizing the diffusive gradients in thin-films (DGT). All samples contained arsenic, and the bioaccessibilities of the colon, intestine and gastric regions ranged from 0.19% to 1.73%, 0.25-1.88% and 0.21-1.70% respectively. The range of DGT-bioaccessibility is 0.01-0.0018%. Three steps of analysis were conducted on inorganic As(III) and As(V). In health risk assessment, the ADDs and HQs of DGT-bioaccessibility were below the threshold levels when compared to computing average daily intake dose (ADD) and hazard quotient (HQ) by bioaccessibility of gastric, intestinal and colon. Additionally, Proteobacteria and Firmicutes were discovered to be the two predominant kinds of gut microbes in this study. Under arsenic exposure, the abundance of Christensenellaceae, Desulfovibrionaceae and Akkermansiaceae increased, but the quantity of Rikenellaceae decreased. These findings revealed that alterations in gut microbiota had an impact on host metabolism.
Topics: Humans; Arsenic; Arsenicals; Gastrointestinal Microbiome
PubMed: 37918077
DOI: 10.1016/j.jhazmat.2023.132863 -
Microorganisms Sep 2023Anthocyanins (Acn) have been reported to have preventive effects on Western diet (WD)-induced non-alcoholic fatty liver disease (NAFLD). However, the amount of Acn that...
Anthocyanins (Acn) have been reported to have preventive effects on Western diet (WD)-induced non-alcoholic fatty liver disease (NAFLD). However, the amount of Acn that reached the bloodstream were less than 1%, suggesting that anthocyanin metabolites (Acn-M) in the gut may contribute to their in vivo effects. This study is focused on a gut microbiota investigation to elucidate the effect of two major Acn-M, protocatechuic acid (PC) and phloroglucinol carboxaldehyde (PG), on NAFLD prevention. C57BL/6N male mice were divided into five groups and fed with a normal diet (ND), WD, WD + 0.5% PC, WD + 0.5% PG and WD + a mixture of 0.25% PC + 0.25% PG (CG) for 12 weeks. The results revealed that WD-fed mice showed a significant increase in final body weight, epididymis fat weight, liver weight and fat accumulation rate, serum total cholesterol, alanine aminotransferase, monocyte chemoattractant protein 1, and 2-thiobarbituric acid reactive substances. At the same time, these indices were significantly decreased by Acn-M in the order of PG, CG > PC. In particular, PG significantly decreased serum glucose and insulin resistance. Gut microbiome analysis revealed that PG significantly increased the relative abundance of , , / ratio, and upregulated glucose degradation pathway. Interestingly, the co-occurrence networks of and in the PC and PG groups were similar to the ND group and different to WD group. These data suggest that PC and PG were able to recover the gut microbiome networks and functions from dysbiosis caused by WD. Therefore, PG might act as a master metabolite for anthocyanins and prevent WD-induced NAFLD and gut dysbiosis.
PubMed: 37894066
DOI: 10.3390/microorganisms11102408 -
The Science of the Total Environment Jan 2024Schwertmannite (Sch) is a highly bioavailable iron-hydroxysulfate mineral commonly found in acid mine drainage contaminated environment rich in sulfate (SO)....
Schwertmannite (Sch) is a highly bioavailable iron-hydroxysulfate mineral commonly found in acid mine drainage contaminated environment rich in sulfate (SO). Microbial-mediated Sch transformation has been well-studied, however, the understanding of how SO availability affects the microbial-mediated Sch transformation and the secondary minerals influence microbes is relatively limited. This study examined the effect of SO availability on the iron-reducing bacteria (FeRB) and SO-reducing bacteria (SRB) consortium-mediated Sch transformation and the resulting secondary minerals in turn on bacteria. Increased SO accelerated the onset of microbial SO reduction, which significantly accelerated Sch reduction transformation. The extent of intermediate products such as lepidocrocite (22.1 % ~ 76.3 %, all treatments) and goethite (15.3 %, 10 mM SO, 5 d) formed by Sch transformation depended on SO concentrations. Vivianite, siderite and iron‑sulfur minerals (e.g., FeS and FeS) were the dominant secondary minerals, in which the relative content of vivianite and siderite decreased while iron‑sulfur minerals increased with increasing SO concentration. Correspondingly, the abundance of FeRB and SRB was negatively and positively correlated with SO concentration, respectively; 1 mM SO promoted the cymA and omcA expression of FeRB, but 10 mM SO lowerd the cymA and omcA expression compared to the 1 mM SO; the dsr expression of SRB related linearly to the SO concentration. These secondary minerals accumulated on the cell surface to form cell encrustations, which limited the growth and gene expression of FeRB and SRB, and even inhibited the activity of SRB in the 10 mM SO treatment group. The 10 mM SO treatment group with low-intensity ultrasound effectively restored the SRB activity for reducing SO by disintegrating the cell-mineral aggregation, further indicating that cell encrustations limited the microbial metabolism. The results highlight the critical role that SO availability can play in controlling microbial transformation of mineral, and the influence of secondary minerals on microbial metabolism.
Topics: Iron; Sulfates; Minerals; Desulfovibrio; Bacteria; Sulfur; Oxidation-Reduction
PubMed: 37820819
DOI: 10.1016/j.scitotenv.2023.167690