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1.
J Environ Manage ; 356: 120747, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38537473

RESUMO

Increasing amounts of solid waste and sludge have created many environmental management problems. Pyrolysis can effectively reduce the volume of solid waste and sludge, but there is still the problem of heavy metal contamination, which limits the application of pyrolysis in environmental management. The intercalated-exfoliated modified vermiculite (IEMV) by intercalators of sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide and octadecyltrimethylammonium bromide were used to control the release of Cd, Cr, Cu, Zn and Pb during pyrolysis process of sludge or solid waste. The retention of heavy metals in sludge was generally better than that in solid waste. The IEMV by octadecyltrimethylammonium bromide as the intercalator calcined 800 °C (STAB-800) was the best additive for heavy metal retention, and the retention of Cr, Cu and Zn was significantly better than that of Pb and Cd. Cr, Cu, Zn and Pb were at low risk, while Cd had considerable risk under certain circumstances. New models were proposed to comprehensively evaluate the results of the risk and forms of heavy metals, and the increasing temperature was beneficial in reducing the hazards of heavy metals by the addition of STAB-800. The reaction mechanism of heavy metals with vermiculite was revealed by simulation of reaction sites, Fukui Function and Frontier Molecular Orbital. Thermal activation-intercalated-exfoliated modified vermiculite (T-IEMV) is more reactive and had more active sites for heavy metals. Mg atoms and outermost O atoms are the main atoms for T-IEMV to react with heavy metals. The Cr, Cu and Zn have better adsorption capacity by T-IEMV than Pb and Cd. This study provides a new insight into managing solid waste and sludge and controlling heavy metal environmental pollution.


Assuntos
Alcanos , Silicatos de Alumínio , Metais Pesados , Compostos de Amônio Quaternário , Esgotos , Esgotos/química , Resíduos Sólidos , Pirólise , Cádmio , Chumbo , Metais Pesados/química
2.
Mar Pollut Bull ; 201: 116224, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38457880

RESUMO

In this study, multiple molecular markers [polycyclic aromatic hydrocarbons (PAHs), linear and branched alkanes, unresolved complex mixture (UCM), hopanes, and steranes] were applied to explore petroleum-related inputs in complex coastal systems influenced by various human-induced pressures. To investigate anthropogenic impacts related to petrogenic emissions, we analysed surface sediments from coastal areas of southern Baltic, including harbour/shipyard channels, offshore dumping sites, shipping routes, and major sinks for particulate matter discharged by large rivers. This study indicates a large spatial variability in the contamination degree of examined sites by petroleum-derived chemicals. Hopanes and steranes along with UCM appeared to have the highest potential to identify petroleum sources in studied locations, whereas investigations based on alkanes and PAHs seemed to be considerably affected by inputs of modern biogenic and combustion-derived materials, respectively. However, the combined use of all these markers provides deeper insight into the complexity of sedimentary organic matter in human-impacted environments.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Humanos , Efeitos Antropogênicos , Poluentes Químicos da Água/análise , Sedimentos Geológicos/química , Monitoramento Ambiental , Alcanos/análise , Petróleo/análise , Biomarcadores , Hidrocarbonetos Policíclicos Aromáticos/análise , Triterpenos Pentacíclicos
3.
Syst Biol Reprod Med ; 70(1): 59-72, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38442080

RESUMO

The present study aimed to identify novel biostimulatory compounds in boar seminal gel (SG), saliva and semen using Gas chromatography-mass spectrometry (GC-MS). The bio-stimulatory effect of SG, SG + saliva and SG + semen on young boar for semen collection as well were employed to study bio-stimulatory effects on gilts and sows. Distilled water (DW) exposure was kept as control. SG, saliva and semen were screened for total 105, 96 and 89 compounds. The highest concentration was of alkanes followed by sugar alcohols, then hydrocarbons, amino acids and fatty acids. Elaidic acid was the novel compound identified in pigs. Significantly higher (p < 0.05) number of males got trained in exposure to SG (80%), SG + saliva (75%) and SG + semen (75%) than control (0%). The time (hrs) taken by young boars to get trained on exposure to combination of SG + saliva (244 ± 22.19) and SG + semen (216 ± 13.14) was lesser (p < 0.05) than SG (356 ± 61.85) alone. Interval (hrs) from initiation of exposure for exhibition of different sexual behaviour by males on exposure to SG, saliva and semen was lesser (p < 0.05) than control. Significantly (p < 0.05) higher number of females showed estrus response to exposure of SG (72.72%), SG + saliva (69.23%) and SG + semen (76.92%) than control (0). Interval (hrs) taken to exhibit estrus was shorter (p < 0.05) in females exposed to SG + saliva (201.88 ± 12.66), SG + semen (198.20 ± 9.42) than SG (262.14 ± 20.06) alone. Interval (hrs) for exhibition of different sexual behaviour by females on exposure to SG + saliva and SG + semen was lesser (p < 0.05) than control. In conclusion, novel compounds were identified in boar seminal gel, saliva and semen with biostimulatory properties have been identified in boar SG, saliva and semen. The combined exposure of SG with saliva and semen has more intense biostimulation effect than SG alone for training of young boars and estrus induction in gilts and sows. Such compounds biostimulatory effects can be exploited for augmenting reproductive efficiency in pigs.


Assuntos
Líquidos Corporais , Saliva , Suínos , Animais , Feminino , Masculino , Sêmen , Reprodução , Alcanos
4.
Water Environ Res ; 96(3): e11009, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38444297

RESUMO

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are an emerging issue in wastewater treatment. High-temperature thermal processes, incineration being time-tested, offer the opportunity to destroy and change the composition of PFAS. The fate of PFAS has been documented through wastewater sludge incinerators, including a multiple hearth furnace (MHF) and a fluidized bed furnace (FBF). The dewatered wastewater sludge feedstock averaged 247- and 1280-µmol targeted PFAS per sample run in MHF and FBF feed, respectively. Stack emissions (reportable for all targeted PFAS from MHF only) averaged 5% of that value with shorter alkyl chain compounds comprising the majority of the targeted PFAS. Wet scrubber water streams accumulated nonpolar fluorinated organics from the furnace exhaust with an average of 0.740- and 0.114-mol F- per sample run, for the MHF and FBF, respectively. Simple alkane PFAS measured at the stack represented 0.5%-4.5% of the total estimated facility greenhouse gas emissions. PRACTITIONER POINTS: The MHF emitted six short chain PFAS from the stack, which were shorter alkyl chain compounds compared with sludge PFAS. The FBF did not consistently emit reportable PFAS from the stack, but contamination complicated the assessment. Five percent of the MHF sludge molar PFAS load was reported in the stack. MHF and FBF wet scrubber water streams accumulated nonpolar fluorinated organics from the furnace exhaust. Ultra-short volatile alkane PFAS measured at the stack represented 0.5%-4.5% of the estimated facility greenhouse gas emissions.


Assuntos
Fluorocarbonos , Gases de Efeito Estufa , Esgotos , Águas Residuárias , Alcanos , Incineração , Água
5.
J Oleo Sci ; 73(4): 625-636, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38556296

RESUMO

The direct incorporation of low viscosity organic liquids (OL) such as dodecane and tributylphosphate (TBP) into fresh geopolymers (GP) is difficult and generally leads to variable amounts of un-incorporated OL remaining outside the hardened geopolymer. Experimentally, it is observed that a regular torque increase during OL incorporation corresponds to a suitable dispersion of the OL in the form of fine micrometric droplets. This can be obtained for TBP and dodecane by adding a small quantity of quaternary ammoniums salts (QAs) such as cetyltrimethylammonium bromide (CTAB). Shorter alkyl chains QAs, such as hexamethyltrimethylammonium (HMTA) can also be used but with a reduced efficiency. The positive impact of CTAB is then confirmed by the Washburn capillary rise method, showing that the interactions between TBP and CTAB-modified metakaolin are weaker compared to untreated powder. Finally, it is observed that the incorporation of TBP into geopolymer slurries is much easier than the incorporation of dodecane. The low interfacial tension measured between TBP and the activating solution (around 8 mN·m -1 ), contrasting with dodecane (29 mN·m -1 ), explains that the dispersion of TBP droplets in fresh metakaolin suspensions is more efficient.


Assuntos
Alcanos , Compostos de Amônio Quaternário , Cetrimônio , Tensão Superficial
6.
Sci Total Environ ; 924: 171462, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38447732

RESUMO

The damage caused by petroleum hydrocarbon pollution to soil and groundwater environment is becoming increasingly significant. The vadose zone is the only way for petroleum hydrocarbon pollutants to leak from surface into groundwater. The spatial distribution characteristics of indigenous microorganisms in vadose zone, considering presence of capillary zones, have rarely been reported. To explore the spatial distribution characteristics of indigenous microorganisms in vadose zone contaminated by petroleum hydrocarbons, a one-dimensional column migration experiment was conducted using n-hexadecane as characteristic pollutant. Soil samples were collected periodically from different heights during experiment. Corresponding environmental factors were monitored online. The microbial community structure and spatial distribution characteristics of the cumulative relative abundance were systematically analyzed using 16S rRNA sequencing. In addition, the microbial degradation mechanism of n-hexadecane was analyzed using metabolomics. The results showed that presence of capillary zone had a strong retarding effect on n-hexadecane infiltration. Leaked pollutants were mainly concentrated in areas with strong capillary action. Infiltration and displacement of NAPL-phase pollutants were major driving force for change in moisture content (θ) and electric conductivity (EC) in vadose zone. The degradation by microorganisms results in a downward trend in potential of hydrogen (pH) and oxidation-reduction potential (ORP). Five petroleum hydrocarbon-degrading bacterial phyla and 11 degradable straight-chain alkane bacterial genera were detected. Microbial degradation was strong in the area near edge of capillary zone and locations of pollutant accumulation. Mainly Sphingomonas and Nocardioides bacteria were involved in microbial degradation of n-hexadecane. Single-end oxidation involved microbial degradation of n-hexadecane (C16H34). The oxygen consumed, hexadecanoic acid (C16H32O2) produced during this process, and release of hydrogen ions (H+) were the driving factors for reduction of ORP and pH. The vadose zone in this study considered presence of capillary zone, which was more in line with actual contaminated site conditions compared with previous studies. This study systematically elucidated vertical distribution characteristics of petroleum hydrocarbon pollutants and spatiotemporal variation characteristics of indigenous microorganisms in vadose zone considered presence of capillary zone. In addition, the n-hexadecane degradation mechanism was elucidated using metabolomics. This study provides theoretical support for development of natural attenuation remediation measures for petroleum-hydrocarbon-contaminated soil and groundwater.


Assuntos
Poluentes Ambientais , Petróleo , Poluentes do Solo , RNA Ribossômico 16S , Alcanos , Hidrocarbonetos/metabolismo , Solo , Oxigênio , Biodegradação Ambiental , Poluentes do Solo/análise , Microbiologia do Solo
7.
Chem Biodivers ; 21(3): e202301779, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38426669

RESUMO

Plant-insect interactions are a driving force into ecosystem evolution and community dynamics. Many insect herbivores enter diapause, a developmental arrest stage in anticipation of adverse conditions, to survive and thrive through seasonal changes. Herein, we investigated the roles of medium- to non-polar metabolites during larval development and diapause in a specialist insect herbivore, Chlosyne lacinia, reared on Aldama robusta leaves. Varying metabolites were determined using gas chromatography-mass spectrometry (GC-MS)-based metabolomics. Sesquiterpenes and steroids were the main metabolites putatively identified in A. robusta leaves, whereas C. lacinia caterpillars were characterized by triterpenes, steroids, fatty acids, and long-chain alkanes. We found out that C. lacinia caterpillars biosynthesized most of the identified steroids and fatty acids from plant-derived ingested metabolites, as well as all triterpenes and long-chain alkanes. Steroids, fatty acids, and long-chain alkanes were detected across all C. lacinia instars and in diapausing caterpillars. Sesquiterpenes and triterpenes were also detected across larval development, yet they were not detected in diapausing caterpillars, which suggested that these metabolites were converted to other molecules prior to the diapause stage. Our findings shed light on the chemical content variation across C. lacinia development and diapause, providing insights into the roles of metabolites in plant-insect interactions.


Assuntos
Diapausa , Lepidópteros , Sesquiterpenos , Triterpenos , Animais , Cromatografia Gasosa-Espectrometria de Massas , Ecossistema , Metabolômica/métodos , Esteroides/metabolismo , Sesquiterpenos/metabolismo , Ácidos Graxos/metabolismo , Alcanos , Triterpenos/metabolismo , Larva
8.
Molecules ; 29(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38474545

RESUMO

Sol g 2 is the major protein in Solenopsis geminata fire ant venom. It shares the highest sequence identity with Sol i 2 (S. invicta) and shares high structural homology with LmaPBP (pheromone-binding protein (PBP) from the cockroach Leucophaea maderae). We examined the specific Sol g 2 protein ligands from fire ant venom. The results revealed that the protein naturally formed complexes with hydrocarbons, including decane, undecane, dodecane, and tridecane, in aqueous venom solutions. Decane showed the highest affinity binding (Kd) with the recombinant Sol g 2.1 protein (rSol g 2.1). Surprisingly, the mixture of alkanes exhibited a higher binding affinity with the rSol g 2.1 protein compared to a single one, which is related to molecular docking simulations, revealing allosteric binding sites in the Sol g 2.1 protein model. In the trail-following bioassay, we observed that a mixture of the protein sol g 2.1 and hydrocarbons elicited S. geminata worker ants to follow trails for a longer time and distance compared to a mixture containing only hydrocarbons. This suggests that Sol g 2.1 protein may delay the evaporation of the hydrocarbons. Interestingly, the piperidine alkaloids extracted have the highest attraction to the ants. Therefore, the mixture of hydrocarbons and piperidines had a synergistic effect on the trail-following of ants when both were added to the protein.


Assuntos
Venenos de Formiga , Formigas , Animais , Proteínas de Transporte/metabolismo , Feromônios/química , Ligantes , Simulação de Acoplamento Molecular , Formigas/química , Alcanos/metabolismo
9.
J Am Chem Soc ; 146(12): 8716-8726, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38484171

RESUMO

The successful biomimetic or chemoenzymatic synthesis of target natural products (NPs) and their derivatives relies on enzyme discovery. Herein, we discover a fungal P450 BTG5 that can catalyze the formation of a bicyclo[3.2.2]nonane structure through an unusual two-step mechanism of dimerization and cyclization in the biosynthesis of beticolin 1, whose bicyclo[3.2.2]nonane skeleton connects an anthraquinone moiety and a xanthone moiety. Further investigation reveals that BTG5-T318 not only determines the substrate selectivity but also alters the catalytic reactions, which allows the separation of the reaction to two individual steps, thereby understanding its catalytic mechanism. It reveals that the first heterodimerization undergoes the common oxidation process for P450s, while the second uncommon formal redox-neutral cyclization step is proved as a redox-mediated reaction, which has never been reported. Therefore, this work advances our understanding of P450-catalyzed reactions and paves the way for expansion of the diversity of this class of NPs through synthetic biology.


Assuntos
Alcanos , Esqueleto , Oxirredução
10.
J Org Chem ; 89(6): 4128-4133, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38407917

RESUMO

Histrionicotoxin (HTX) alkaloids, which are isolated from Colombian poison dart frogs, are analgesic neurotoxins that modulate nicotinic acetylcholine receptors (nAChRs) as antagonists. Perhydrohistrionicotoxin (pHTX) is the potent synthetic analogue of HTX and possesses a 1-azaspiro[5.5]undecane skeleton common to the HTX family. Here, we show for the first time the divergent nine-step synthesis of pHTX and its three stereoisomers from the known aldehyde through a one-step construction of the 1-azaspiro[5.5]undecane framework from a linear amino ynone substrate. Surprisingly, some pHTX diastereomers exhibited antagonistic activities on the chicken α4ß2-neuronal nAChRs that were more potent than pHTX.


Assuntos
Venenos de Anfíbios , Galinhas , Receptores Nicotínicos , Animais , Alcanos
11.
Extremophiles ; 28(1): 18, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38353731

RESUMO

We have accidentally found that a thermophilic Geobacillus kaustophilus HTA426 is capable of degrading alkanes although it has no alkane oxygenating enzyme genes. Our experimental results revealed that a putative ribonucleotide reductase small subunit GkR2loxI (GK2771) gene encodes a novel heterodinuclear Mn-Fe alkane monooxygenase/hydroxylase. GkR2loxI protein can perform two-electron oxidations similar to homonuclear diiron bacterial multicomponent soluble methane monooxygenases. This finding not only answers a long-standing question about the substrate of the R2lox protein clade, but also expands our understanding of the vast diversity and new evolutionary lineage of the bacterial alkane monooxygenase/hydroxylase family.


Assuntos
Geobacillus , Ribonucleotídeo Redutases , Ribonucleotídeo Redutases/genética , Oxigenases de Função Mista/genética , Geobacillus/genética , Alcanos
12.
Biomolecules ; 14(2)2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38397464

RESUMO

Plant cuticular wax forms a hydrophobic structure in the cuticle layer covering epidermis as the first barrier between plants and environments. Ammopiptanthus mongolicus, a leguminous desert shrub, exhibits high tolerances to multiple abiotic stress. The physiological, chemical, and transcriptomic analyses of epidermal permeability, cuticular wax metabolism and related gene expression profiles under osmotic stress in A. mongolicus leaves were performed. Physiological analyses revealed decreased leaf epidermal permeability under osmotic stress. Chemical analyses revealed saturated straight-chain alkanes as major components of leaf cuticular wax, and under osmotic stress, the contents of total wax and multiple alkane components significantly increased. Transcriptome analyses revealed the up-regulation of genes involved in biosynthesis of very-long-chain fatty acids and alkanes and wax transportation under osmotic stress. Weighted gene co-expression network analysis identified 17 modules and 6 hub genes related to wax accumulation, including 5 enzyme genes coding KCS, KCR, WAX2, FAR, and LACS, and an ABCG transporter gene. Our findings indicated that the leaf epidermal permeability of A. mongolicus decreased under osmotic stress to inhibit water loss via regulating the expression of wax-related enzyme and transporter genes, further promoting cuticular wax accumulation. This study provided new evidence for understanding the roles of cuticle lipids in abiotic stress tolerance of desert plants.


Assuntos
Perfilação da Expressão Gênica , Folhas de Planta , Pressão Osmótica , Folhas de Planta/química , Água/metabolismo , Alcanos , Regulação da Expressão Gênica de Plantas
13.
J Insect Sci ; 24(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38387433

RESUMO

The spotted amber ladybird, Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), is known to be a potent predator of aphids, psyllids, whiteflies, mealybugs, and some butterfly species. This ladybeetle overwinters in the diapausing adult stage. The current study aimed to evaluate the impact of diapause on the energy resources and cuticular hydrocarbons (CHCs) of the female ladybeetle, specifically comparing the changes in glycogen, lipid, and protein contents, and CHCs profile of diapausing and non-diapausing adults. In this study, gas chromatography-mass was used to analyze whole-body extracts of the beetles. Results showed no significant differences between the amount of glycogen, lipid, and protein contents of diapausing and non-diapausing ladybeetle. The CHCs profile of H. variegata consisted of 24 hydrocarbons categorized into 2 groups: linear aliphatic hydrocarbons (n-alkanes) and methyl-branched hydrocarbons (17 molecules), as well as unsaturated cyclic compounds (7 molecules). The n-alkanes, with 14 compounds, were identified as the primary constituents of the CHCs of the ladybeetle. Six molecules were common to non-diapausing and diapausing beetles, 5 were exclusive to non-diapausing beetles, and 13 were exclusive to diapausing beetles. Moreover, we noted a significant difference in the quantity and quality of CHCs between diapausing and non-diapausing beetles, with diapausing beetles synthesizing more CHCs with longer chains. This disparity in CHC profiles was concluded to be an adaptation of H. variegata to survive harsh environmental conditions during diapause.


Assuntos
Besouros , Diapausa de Inseto , Diapausa , Feminino , Animais , Hidrocarbonetos , Besouros/fisiologia , Alcanos , Glicogênio , Lipídeos
14.
Sci Rep ; 14(1): 3779, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38360875

RESUMO

Integral proteins or enzymes are still challenging to purify into their native state because of their need for an amphipathic environment and cofactors. Alkane hydroxylase (AlkB) is a membrane-bound enzyme that catalyzes the hydroxylation of a range of alkanes that have a broad spectrum of applications. In the current study, a novel approach has been explored for partial purification of alkane hydroxylase (AlkB) in its native state through restructuring the lipid bilayer of Penicillium chrysogenum SNP5 into a liposome to extend the native and protective environment to AlkB enzyme. Three different methods i.e., reverse-phase evaporation method (RPEM), detergent-based method (DBM), and ethanol injection method (EIM) have been used for reconstituting its native membrane into liposome. On characterizing liposomes through fluorescence imaging, AFM, and particle size analysis, the reverse-phase evaporation method gave the best results based on the size distribution (i.e., 100-300 nm), the morphology of liposomes, and maximum AlkB specific activity (i.e., 140.68 U/mg). The maximum reconstitution efficiency of 29.48% was observed in RPEM followed by 17.3% in DBM and 12.3% in EIM. On the characterization of the purified AlkB, the molecular weight was measured of 44.6 KDa and the thermostability of liposomes synthesized with the RPEM method was obtained maximum at 55 °C. This approach may open a new strategy for the purification of integral enzymes/proteins in their native state in the field of protein purification and its applications in diversified industries.


Assuntos
Alcanos , Lipossomos , Citocromo P-450 CYP4A/metabolismo , Hidroxilação , Alcanos/metabolismo
15.
J Nat Prod ; 87(3): 456-469, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38395785

RESUMO

The phytochemical investigation of the leaves and trunk bark of a specimen of Ocotea aciphylla collected in the southern portion of the Amazon forest led to the isolation of an oxabicyclo[3.2.2]nonane-type neolignan and 15 bicyclo[3.2.1]octanoid neolignans, 14 of which are unreported compounds (2-15), including one with an unusual oxidation pattern of the side chain at C-1' and two rare 7.1',8.3'-connected bicyclo[3.2.1]octanoid derivatives. Their structures and relative configurations were determined by extensive spectrometric analysis based on 1D- and 2D-NMR spectroscopy and HRESIMS data, while their absolute configurations were unambiguously assigned using electronic and vibrational circular dichroism data assisted by density functional theory calculations. Additionally, known sesquiterpenes, phenylpropanoids, and phytosterols were also isolated.


Assuntos
Lignanas , Ocotea , Lignanas/química , Ocotea/química , Alcanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Dicroísmo Circular
16.
ISME J ; 18(1)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38365230

RESUMO

Hadarchaeota inhabit subsurface and hydrothermally heated environments, but previous to this study, they had not been cultured. Based on metagenome-assembled genomes, most Hadarchaeota are heterotrophs that grow on sugars and amino acids, or oxidize carbon monoxide or reduce nitrite to ammonium. A few other metagenome-assembled genomes encode alkyl-coenzyme M reductases (Acrs), ß-oxidation, and Wood-Ljungdahl pathways, pointing toward multicarbon alkane metabolism. To identify the organisms involved in thermophilic oil degradation, we established anaerobic sulfate-reducing hexadecane-degrading cultures from hydrothermally heated sediments of the Guaymas Basin. Cultures at 70°C were enriched in one Hadarchaeon that we propose as Candidatus Cerberiarchaeum oleivorans. Genomic and chemical analyses indicate that Ca. C. oleivorans uses an Acr to activate hexadecane to hexadecyl-coenzyme M. A ß-oxidation pathway and a tetrahydromethanopterin methyl branch Wood-Ljungdahl (mWL) pathway allow the complete oxidation of hexadecane to CO2. Our results suggest a syntrophic lifestyle with sulfate reducers, as Ca. C. oleivorans lacks a sulfate respiration pathway. Comparative genomics show that Acr, mWL, and ß-oxidation are restricted to one family of Hadarchaeota, which we propose as Ca. Cerberiarchaeaceae. Phylogenetic analyses further indicate that the mWL pathway is basal to all Hadarchaeota. By contrast, the carbon monoxide dehydrogenase/acetyl-coenzyme A synthase complex in Ca. Cerberiarchaeaceae was horizontally acquired from Bathyarchaeia. The Acr and ß-oxidation genes of Ca. Cerberiarchaeaceae are highly similar to those of other alkane-oxidizing archaea such as Ca. Methanoliparia and Ca. Helarchaeales. Our results support the use of Acrs in the degradation of petroleum alkanes and suggest a role of Hadarchaeota in oil-rich environments.


Assuntos
Alcanos , Mesna , Anaerobiose , Filogenia , Alcanos/metabolismo , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Sulfatos/metabolismo
17.
Chemosphere ; 352: 141400, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340993

RESUMO

The analysis of chlorinated paraffins (CPs) has become a major analytical challenge. GC-ECNI-HRMS coupling is often used to analyse and quantify them. However, the influence of certain GC and ECNI parameters on the responses of polychlorinated n-alkanes (PCAs), the dominant components of CPs, has hardly been studied. In this paper, we investigated not only the influence of GC column characteristics, but also oven, GC inlet and source temperatures for simultaneous analysis of PCAs with chain-length ranging from 10 up to 20 carbon atoms (PCAs-C10-20). Particular attention was paid to the absolute response and PCA homologue group pattern obtained for a CP technical mixture. The optimum conditions for a wide homologue group determination were GC inlet, final gradient and ion source temperatures set at 220-240 °C, 340 °C and 200 °C. At the same time, a higher response was obtained with the Optima 5HT column compared to Optima 1 column, and with a length and film thickness of 12.5 m and 0.25 µm, respectively. The homologue group pattern of the technical mixture studied was significantly modified as a function of the source and GC inlet temperatures, film thickness and composition of the stationary phase. Here we recommend conditions that will improve the overall PCA pattern, in order to better characterise their occurrence in future environmental monitoring and exposure assessment.


Assuntos
Hidrocarbonetos Clorados , Parafina , Cromatografia Gasosa-Espectrometria de Massas/métodos , Parafina/análise , Hidrocarbonetos Clorados/análise , Espectrometria de Massas , Monitoramento Ambiental/métodos , Alcanos/análise
18.
Chemosphere ; 352: 141401, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38346520

RESUMO

The analysis of chlorinated paraffins (CPs) is today an analytical challenge. Indeed, it is still impractical to describe their real composition in terms of polychlorinated alkanes (PCAs) homologue groups, which dominate technical mixtures. The co-elution of PCA congeners generates interferences due to the competition phenomena which occur during the ionisation process as well as to the dependence of the ionisation sources on the PCA chemistry. Therefore, the aim of this study was to investigate the influence of chromatographic separation, by LC-ESI-HRMS coupling, on the PCA homologue group pattern and, eventually, on their determination in food samples from interlaboratory studies. For this, three different mobile phases and six LC chromatographic columns were studied in order to optimise the analysis of CP mixtures. The first results showed that the use of a MeOH/H2O mobile phase reveals more appropriately the higher chlorinated PCAs. However, using ACN/H2O led to less ion species, with almost exclusively [M + Cl]- adducts, formed using post-column dichloromethane addition. Regarding the choice of the stationary phases, Hypercarb column provided a completely different homologue group pattern from the other chromatographic columns, in relation with the stronger retention of PCAs. Among the other columns, the C30 column better highlighted the short-chain PCAs compared to the C18 column conventionally used. Because the regulations now concern short-chain CPs, the quantification of food samples was then carried out on the C30 column. The optimised LC-ESI-HRMS conditions using C30 column and MeOH/H2O solvent mixture led to a quantification of PCAs in samples from interlaboratory studies with satisfactory accuracy (|Z-score| ≤ 2) and precision (<15%).


Assuntos
Hidrocarbonetos Clorados , Parafina , Parafina/análise , Hidrocarbonetos Clorados/análise , Espectrometria de Massas/métodos , Cromatografia Líquida/métodos , Cloreto de Metileno , Alcanos/análise
19.
Med Mycol ; 62(3)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38389246

RESUMO

Candida albicans is a dimorphic opportunistic pathogen in immunocompromised individuals. We have previously demonstrated that sodium houttuyfonate (SH), a derivative of medicinal herb Houttuynia cordata Thunb, was effective for antifungal purposes. However, the physical impediment of SH by C. albicans ß-glucan may weaken the antifungal activity of SH. In this study, the interactions of SH with cell wall (CW), extracellular matrix (EM), CW ß-glucan, and a commercial ß-glucan zymosan A (ZY) were inspected by XTT assay and total plate count in a standard reference C. albicans SC5314 as well as two clinical fluconazole-resistant strains Z4935 and Z5172. After treatment with SH, the content and exposure of CW ß-glucan, chitin, and mannan were detected, the fungal clearance by phagocytosis of RAW264.7 and THP-1 was examined, and the gene expressions and levels of cytokines TNF-ɑ and IL-10 were also monitored. The results showed that SH could be physically impeded by ß-glucan in CW, EM, and ZY. This impediment subsequently triggered the exposure of CW ß-glucan and chitin with mannan masked in a time-dependent manner. SH-induced ß-glucan exposure could significantly enhance the phagocytosis and inhibit the growth of C. albicans. Meanwhile, the SH-pretreated fungal cells could greatly stimulate the cytokine gene expressions and levels of TNF-ɑ and IL-10 in the macrophages. In sum, the strategy that the instant physical impediment of C. albicans CW to SH, which can induce the exposure of CW ß-glucan may be universal for C. albicans in response to physical deterrent by antifungal drugs.


Assuntos
Alcanos , Candida albicans , Sulfitos , beta-Glucanas , Humanos , Antifúngicos/uso terapêutico , beta-Glucanas/farmacologia , Interleucina-10/metabolismo , Interleucina-10/farmacologia , Fator de Necrose Tumoral alfa , Mananas , Fagocitose , Quitina/metabolismo , Parede Celular/metabolismo
20.
Environ Sci Pollut Res Int ; 31(15): 22431-22440, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38407710

RESUMO

Sediment source fingerprinting using biomarker properties has led to new insights in our understanding of land use contributions to time-integrated suspended sediment samples at catchment scale. A time-integrated mass-flux sampler (TIMS; also known as the 'Phillips' sampler), a cost-effective approach for suspended sediment collection in situ. Such samplers are widely being used to collect sediment samples for source fingerprinting purposes, including studies using biomarkers as opposed to more conventional tracer properties. Here, we assessed the performance of TIMS for collecting representative sediment samples for biomarkers during high discharge events in a small lowland grassland-dominated catchment. Concentrations of long odd-chain n-alkanes (> C23) and both saturated free and bound fatty acids (C14-C32), as well as compound-specific 13C were compared between sediment collected by both TIMS and autosamplers (ISCO). The results showed that concentrations of alkanes, free fatty acids, and bound fatty acids are consistently comparable between TIMS and ISCO suspended sediment samples. Similarly, compound-specific 13C signals were not found to be significantly different in the suspended sediment samples collected using the different samplers. However, different magnitudes of resemblance in biomarker concentrations and compositions between the samples collected using the two sediment collection methods were confirmed by overlapping index and symmetric coordinates-based correlation analysis. Here, the difference is attributed to the contrasting temporal basis of TIMS (time-integrated) vs. ISCO (discrete) samples, as well as potential differences in the particle sizes collected by these different sediment sampling methods. Nevertheless, our findings suggest that TIMS can be used to generate representative biomarker data for suspended sediment samples collected during high discharge events.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Ácidos Graxos , Biomarcadores , Alcanos/análise
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