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1.
Environ Res ; 255: 119209, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38782336

RESUMO

Nitrate/nitrite-dependent anaerobic methane oxidation (n-DAMO) process is a promising wastewater treatment technology, but the slow microbial growth rate greatly hinders its practical application. Although high-level nitrogen removal and excellent biomass accumulation have been achieved in n-DAMO granule process, the formation mechanism of n-DAMO granules remains unresolved. To elucidate the role of functional microbes in granulation, this study attempted to cultivate granules dominated by n-DAMO microorganisms and granules coupling n-DAMO with anaerobic ammonium oxidation (Anammox). After long-term operation, dense granules were developed in the two systems where both n-DAMO archaea and n-DAMO bacteria were enriched, whereas granulation did not occur in the other system dominated by n-DAMO bacteria. Extracellular polymeric substances (EPS) measurement indicated the critical role of EPS production in the granulation of n-DAMO process. Metagenomic and metatranscriptomic analyses revealed that n-DAMO archaea and Anammox bacteria were active in EPS biosynthesis, while n-DAMO bacteria were inactive. Consequently, more EPS were produced in the systems containing n-DAMO archaea and Anammox bacteria, leading to the successful development of n-DAMO granules. Furthermore, EPS biosynthesis in n-DAMO systems is potentially regulated by acyl-homoserine lactones and c-di-GMP. These findings not only provide new insights into the mechanism of granule formation in n-DAMO systems, but also hint at potential strategies for management of the granule-based n-DAMO process.


Assuntos
Archaea , Bactérias , Oxirredução , Archaea/metabolismo , Archaea/genética , Anaerobiose , Bactérias/metabolismo , Bactérias/genética , Metano/metabolismo , Eliminação de Resíduos Líquidos/métodos , Nitratos/metabolismo , Compostos de Amônio/metabolismo , Nitritos/metabolismo , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Reatores Biológicos/microbiologia , Águas Residuárias/microbiologia
2.
Environ Res ; 252(Pt 1): 118810, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38552829

RESUMO

Nitrate/nitrite-dependent anaerobic methane oxidation (n-DAMO) process offers a promising solution for simultaneously achieving methane emissions reduction and efficient nitrogen removal in wastewater treatment. Although nitrogen removal at a practical rate has been achieved by n-DAMO biofilm process, the mechanisms of biofilm formation and nitrogen transformation remain to be elucidated. In this study, n-DAMO biofilms were successfully developed in the membrane aerated moving bed biofilm reactor (MAMBBR) and removed nitrate at a rate of 159 mg NO3--N L-1 d-1. The obvious increase in the content of extracellular polymeric substances (EPS) indicated that EPS production was important for biofilm development. n-DAMO microorganisms dominated the microbial community, and n-DAMO bacteria were the most abundant microorganisms. However, the expression of biosynthesis genes for proteins and polysaccharides encoded by n-DAMO archaea was significantly more active compared to other microorganisms, suggesting the central role of n-DAMO archaea in EPS production and biofilm formation. In addition to nitrate reduction, n-DAMO archaea were revealed to actively express dissimilatory nitrate reduction to ammonium and nitrogen fixation. The produced ammonium was putatively converted to dinitrogen gas through the joint function of n-DAMO archaea and n-DAMO bacteria. This study revealed the biofilm formation mechanism and nitrogen-transformation network in n-DAMO biofilm systems, shedding new light on promoting the application of n-DAMO process.


Assuntos
Biofilmes , Reatores Biológicos , Metano , Nitratos , Oxirredução , Biofilmes/crescimento & desenvolvimento , Metano/metabolismo , Anaerobiose , Nitratos/metabolismo , Reatores Biológicos/microbiologia , Nitrogênio/metabolismo , Archaea/metabolismo , Archaea/genética , Archaea/fisiologia , Bactérias/metabolismo , Bactérias/genética , Eliminação de Resíduos Líquidos/métodos
3.
J Environ Manage ; 358: 120832, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599089

RESUMO

Polyethylene (PE) is the most productive plastic product and includes three major polymers including high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) variation in the PE depends on the branching of the polymer chain and its crystallinity. Tenebrio obscurus and Tenebrio molitor larvae biodegrade PE. We subsequently tested larval physiology, gut microbiome, oxidative stress, and PE degradation capability and degradation products under high-purity HDPE, LLDPE, and LDPE powders (<300 µm) diets for 21 days at 65 ± 5% humidity and 25 ± 0.5 °C. Our results demonstrated the specific PE consumption rates by T. molitor was 8.04-8.73 mg PE ∙ 100 larvae-1⋅day-1 and by T. obscurus was 7.68-9.31 for LDPE, LLDPE and HDPE, respectively. The larvae digested nearly 40% of the ingested three PE and showed similar survival rates and weight changes but their fat content decreased by 30-50% over 21-day period. All the PE-fed groups exhibited adverse effects, such as increased benzoquinone concentrations, intestinal tissue damage and elevated oxidative stress indicators, compared with bran-fed control. In the current study, the digestive tract or gut microbiome exhibited a high level of adaptability to PE exposure, altering the width of the gut microbial ecological niche and community diversity, revealing notable correlations between Tenebrio species and the physical and chemical properties (PCPs) of PE-MPs, with the gut microbiome and molecular weight change due to biodegradation. An ecotoxicological simulation by T.E.S.T. confirmed that PE degradation products were little ecotoxic to Daphnia magna and Rattus norvegicus providing important novel insights for future investigations into the environmentally-friendly approach of insect-mediated biodegradation of persistent plastics.


Assuntos
Biodegradação Ambiental , Larva , Microplásticos , Polietileno , Tenebrio , Animais , Tenebrio/metabolismo , Polietileno/metabolismo , Microplásticos/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Estresse Oxidativo
4.
Transgenic Res ; 32(4): 251-264, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37468714

RESUMO

Channel catfish, Ictalurus punctatus, have limited ability to synthesize Ω-3 fatty acids. The ccßA-msElovl2 transgene containing masu salmon, Oncorhynchus masou, elongase gene driven by the common carp, Cyprinus carpio, ß-actin promoter was inserted into the channel catfish melanocortin-4 receptor (mc4r) gene site using the two-hit two-oligo with plasmid (2H2OP) method. The best performing sgRNA resulted in a knockout mutation rate of 92%, a knock-in rate of 54% and a simultaneous knockout/knock-in rate of 49%. Fish containing both the ccßA-msElovl2 transgene knock-in and mc4r knockout (Elovl2) were 41.8% larger than controls at 6 months post-hatch (p = 0.005). Mean eicosapentaenoic acid (EPA, C20:5n-3) levels in Elov2 mutants and mc4r knockout mutants (MC4R) were 121.6% and 94.1% higher than in controls, respectively (p = 0.045; p = 0.025). Observed mean docosahexaenoic acid (DHA, C22:6n-3) and total EPA + DHA content was 32.8% and 45.1% higher, respectively, in Elovl2 transgenic channel catfish than controls (p = 0.368; p = 0.025). To our knowledge this is the first example of genome engineering to simultaneously target transgenesis and knock-out a gene in a commercially important aquaculture species for multiple improved performance traits. With a high transgene integration rate, improved growth, and higher omega-3 fatty acid content, the use of Elovl2 transgenic channel catfish appears beneficial for application on commercial farms.


Assuntos
Carpas , Ictaluridae , Oncorhynchus , Animais , Ictaluridae/genética , Elongases de Ácidos Graxos/genética , Sistemas CRISPR-Cas/genética , RNA Guia de Sistemas CRISPR-Cas , Animais Geneticamente Modificados/genética , Oncorhynchus/genética
5.
Environ Sci Technol ; 57(50): 20975-20991, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-37931214

RESUMO

Nitrate/nitrite-dependent anaerobic oxidation of methane (n-DAMO) is a recently discovered process, which provides a sustainable perspective for simultaneous nitrogen removal and greenhouse gas emission (GHG) mitigation by using methane as an electron donor for denitrification. However, the engineering roadmap of the n-DAMO process is still unclear. This work constitutes a state-of-the-art review on the classical and most recently discovered metabolic mechanisms of the n-DAMO process. The versatile combinations of the n-DAMO process with nitrification, nitritation, and partial nitritation for nitrogen removal are also clearly presented and discussed. Additionally, the recent advances in bioreactor development are systematically reviewed and evaluated comprehensively in terms of methane supply, biomass retention, membrane requirement, startup time, reactor performance, and limitations. The key issues including enrichment and operation strategy for the scaling up of n-DAMO-based processes are also critically addressed. Moreover, the challenges inherent to implementing the n-DAMO process in practical applications, including application scenario recognition, GHG emission mitigation, and operation under realistic conditions, are highlighted. Finally, prospects as well as opportunities for future research are proposed. Overall, this review provides a roadmap for potential applications and further development of the n-DAMO process in the field of wastewater treatment.


Assuntos
Compostos de Amônio , Nitratos , Nitratos/metabolismo , Nitritos/metabolismo , Nitrificação , Anaerobiose , Metano , Desnitrificação , Compostos de Amônio/metabolismo , Oxirredução , Reatores Biológicos , Nitrogênio/metabolismo
6.
Exp Cell Res ; 417(2): 113226, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35644412

RESUMO

AIM: The molecular mechanism of differentiation in bone marrow mesenchymal stem cells (BMSCs) preserves to be further elucidated. LncRNA HOTTIP has been proven to accelerate osteogenic differentiation, but the regulation mechanism is still unclear. METHODS: The human BMSCs (hBMSCs) were isolated and identified by the antigen CD29, CD34, CD44, CD45, and CD90 through flow cytometry. The osteogenic state was determined by the ALP Detection Kit and Alizarin red staining. The tube formation was observed under a microscope. HOTTIP expression level, DLX2 and TAF15, Wnt/ß-catenin pathway, and transcriptional markers in osteogenesis and angiogenesis were examined with Western blot and RT-qPCR, respectively. The combination of TAF15 with lncRNA HOTTIP and DLX2 was detected by RNA immunoprecipitation (RIP) and RNA pulldown assays. RESULTS: The outcomes revealed that HOTTIP was noticeably up-regulated accompanied by the osteogenic transcriptional factor in the process of osteoblast differentiation and angiogenesis. Besides, HOTTIP enhanced alkaline phosphatase (ALP) activity, accelerated osteogenic differentiation and angiogenesis along with up-regulation of osteogenic and angiogenic-related gene expression, by interaction with TAF15 to stabilize DLX2. CONCLUSION: Taken together, our outcomes reveal that lncRNA HOTTIP accelerated osteogenic differentiation and angiogenesis by interaction with TAF15 to stabilize DLX2.


Assuntos
Células-Tronco Mesenquimais , RNA Longo não Codificante , Fatores Associados à Proteína de Ligação a TATA , Células da Medula Óssea/metabolismo , Diferenciação Celular , Células Cultivadas , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Osteogênese/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt
7.
Environ Res ; 220: 115184, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36586714

RESUMO

As a promising technology, the combination of nitrate/nitrite-dependent anaerobic methane oxidation (n-DAMO) with Anammox offers a solution to achieve effective and sustainable wastewater treatment. However, this sustainable process faces challenges to accumulate sufficient biomass for reaching practical nitrogen removal performance. This study developed an innovative membrane aerated moving bed biofilm reactor (MAMBBR), which supported sufficient methane supply and excellent biofilm attachment, for cultivating biofilms coupling n-DAMO with Anammox. Biofilms were developed rapidly on the polyurethane foam with the supply of ammonium and nitrate, achieving the bioreactor performance of 275 g N m-3 d-1 within 102 days. After the preservation at -20 °C for 8 months, the biofilm was successfully reactivated and achieved 315 g N m-3 d-1 after 188 days. After reactivation, MAMBBR was applied to treat synthetic sidestream wastewater. Up to 99.9% of total nitrogen was removed with the bioreactor performance of 4.0 kg N m-3 d-1. Microbial community analysis and mass balance calculation demonstrated that n-DAMO microorganisms and Anammox bacteria collectively contributed to nitrogen removal in MAMBBR. The MAMBBR developed in this study provides an ideal system of integrating n-DAMO with Anammox for sustainable wastewater treatment.


Assuntos
Compostos de Amônio , Nitratos , Desnitrificação , Metano , Nitrogênio , Oxidação Anaeróbia da Amônia , Anaerobiose , Reatores Biológicos/microbiologia , Oxirredução , Biofilmes
8.
Zhongguo Zhong Yao Za Zhi ; 48(12): 3360-3372, 2023 Jun.
Artigo em Zh | MEDLINE | ID: mdl-37382019

RESUMO

UPLC-Q-Exactive-MS/MS and network pharmacology were employed to preliminarily study the active components and mechanism of Jinwugutong Capsules in the treatment of osteoporosis. Firstly, UPLC-Q-Exactive-MS/MS was employed to characterize the chemical components of Jinwugutong Capsules, and network pharmacology was employed to establish the "drug-component-target-pathway-disease" network. The key targets and main active components were thus obtained. Secondly, AutoDock was used for the molecular docking between the main active components and key targets. Finally, the animal model of osteoporosis was established, and the effect of Jinwugutong Capsules on the expression of key targets including RAC-alpha serine/threonine-protein kinase(AKT1), albumin(ALB), and tumor necrosis factor-alpha(TNF-α) was determined by enzyme-linked immunosorbent assay(ELISA). A total of 59 chemical components were identified from Jinwugutong Capsules, among which coryfolin, 8-prenylnaringenin, demethoxycurcumin, isobavachin, and genistein may be the main active components of Jinwugutong Capsules in treating osteoporosis. The topological analysis of the protein-protein interaction(PPI) network revealed 10 core targets such as AKT1, ALB, catenin beta 1(CTNNB1), TNF, and epidermal growth factor receptor(EGFR). The Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment showed that Jinwugutong Capsules mainly exerted the therapeutic effect by regulating the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT) signaling pathway, neuroactive ligand-receptor interaction, mitogen-activated protein kinase(MAPK) signaling pathway, Rap1 signaling pathway and so on. Molecular docking showed that the main active components of Jinwugutong Capsules well bound to the key targets. ELISA results showed that Jinwugutong Capsules down-regulated the protein levels of AKT1 and TNF-α and up-regulated the protein level of ALB, which preliminarily verified the reliability of network pharmacology. This study indicates that Jinwugutong Capsules may play a role in the treatment of osteoporosis through multiple components, targets, and pathways, which can provide reference for the further research.


Assuntos
Farmacologia em Rede , Fator de Necrose Tumoral alfa , Animais , Fator de Necrose Tumoral alfa/genética , Cápsulas , Simulação de Acoplamento Molecular , Fosfatidilinositol 3-Quinases , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem
9.
Fish Shellfish Immunol ; 126: 311-317, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35636698

RESUMO

Constructs bearing the cecropin B gene from the moth Hyalophora cecropia, driven by the cytomegalovirus (CMV) promoter, or the common carp beta-actin (ß-actin) promoter were transferred to channel catfish, Ictalurus punctatus via electroporation. One F3 channel catfish family transgenic for cecropin transgene driven by the CMV promoter, and one F1 channel catfish family transgenic for cecropin transgene driven by the common carp ß-actin promoter were produced. F3 and F1 individuals exhibited enhanced disease resistance when challenged in tanks with Edwardsiella ictaluri, the causative agent of enteric septicemia of catfish (ESC). Inheritance of the transgene by the F1 and F3 generation was 15% and 60%, respectively. Growth rates of the cecropin transgenic and non-transgenic full siblings (controls) channel catfish were not different (P > 0.05). All transgenic fish showed significant resistance to infection by ESC at day 3 and day 4 post exposure (P = 0.005). No correlation was detected between body weight and time to death for all genetic groups (P = 0.34). Results of our study confirmed that genetic enhancement of E. ictaluri resistance can be achieved by cecropin transgenesis in channel catfish. In addition to survival rate, improving survival time is essential because the extension of survival time gives a better chance to apply treatments to stop the bacterial infection.


Assuntos
Peixes-Gato , Cecropinas , Infecções por Citomegalovirus , Infecções por Enterobacteriaceae , Doenças dos Peixes , Ictaluridae , Actinas/genética , Animais , Peixes-Gato/genética , Edwardsiella ictaluri/fisiologia , Infecções por Enterobacteriaceae/microbiologia , Doenças dos Peixes/microbiologia , Técnicas de Transferência de Genes , Ictaluridae/genética , Ictaluridae/microbiologia
10.
Bioorg Chem ; 123: 105749, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35364556

RESUMO

Two pairs of unprecedented enantiomeric phthalide dimers, spiroligustolides A (1a/1b) and B (2a/2b), featuring a unique spiroorthoster linkage between two monomeric units to form a 5/6/5/6/6-fused ring system, were isolated from the roots of Ligusticum chuanxiong. The structures and relative configurations of 1 and 2 were determined by HR-ESI-MS, IR, and NMR spectroscopic data, coupled with single-crystal X-ray diffraction analysis, and the absolute configurations of 1a, 1b, 2a, and 2b were established by comparing the experimental and calculated electronic circular dichroism (ECD) data. Plausible biosynthetic pathway for 1 and 2 was proposed. Moreover, compounds 1, 1b, and 2b showed remarkable inhibitory activities on Cav3.1 calcium channel with IC50 values of 8.34, 7.08, and 8.60 µM, respectively.


Assuntos
Benzofuranos , Ligusticum , Benzofuranos/química , Benzofuranos/farmacologia , Canais de Cálcio , Ligusticum/química , Estrutura Molecular , Estereoisomerismo
11.
Chem Biodivers ; 19(7): e202200454, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35604198

RESUMO

Five new fawcettimine-type Lycopodium alkaloids, hupertimines A-E (1-5), were discovered from the whole plant of Huperzia serrata, along with two known alkaloids, 8α-hydroxyphlegmariurine B (6) and 8ß-hydroxyphlegmariurine B (7). The structures of 1-7 were identified through HR-MS, IR, 1 H, 13 C, and 2D NMR, and single-crystal X-ray diffraction analysis. Structurally, compound 1 was the fourth example of Lycopodium alkaloid with an ether linkage between C-5 and C-13 and 2 was the third example of Lycopodium alkaloid with a 5/5/5/5/6 pentacyclic ring system and featuring a 1-aza-7-oxabicyclo[2.2.1]heptane unit. Compounds 1-7 were tested for their BACE1 inhibitory activity. In addition, the correct 1 H- and 13 C-NMR data for 7 were reported in current study.


Assuntos
Alcaloides , Huperzia , Lycopodium , Alcaloides/química , Alcaloides/farmacologia , Secretases da Proteína Precursora do Amiloide , Ácido Aspártico Endopeptidases , Huperzia/química , Lycopodium/química , Estrutura Molecular
12.
Chem Biodivers ; 19(7): e202200429, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35638146

RESUMO

Four highly oxygenated sesquiterpenoids, illimicranolides A (1) and B (2), and illicinolides E (3) and F (4), were obtained from the fruits of Illicium micranthum Dunn, as well as one known analog, illicinolide B (5). The chemical structures of 1-4 were determined comprehensively by 1D (1 H and 13 C) and 2D (HMBC, HSQC, 1 H-1 H COSY, and ROESY) NMR, and HR-ESI-MS data. Structurally, compound 1 was an unprecedented sesquiterpenoid with a 5/5/6/5-fused tetracyclic ring system and was the first seco-prezizaane sesquiterpenoid featuring a 11,8-γ-lactone ring. Compounds 3 and 4 were the fifth and sixth examples of illicinolide-type sesquiterpenoids. Moreover, compound 1 demonstrated neurotrophic activity of NGF-induced PC12 cells with differentiation rate of 10.34 % at a concentration of 10 µM.


Assuntos
Illicium , Sesquiterpenos , Animais , Frutas , Illicium/química , Lactonas/química , Estrutura Molecular , Ratos , Sesquiterpenos/química , Sesquiterpenos/farmacologia
13.
Chem Biodivers ; 19(1): e202100868, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34837325

RESUMO

Two new seco-prezizaane-type sesquiterpenes, 2ß-hydroxy-6-deoxyneoanisatin (1) and 3,4-anhydro-2-oxo-1α-hydroxy-6-deoxyneoanisatin (2), and two new prenylated C6 -C3 compounds, illilanceofunones A (3) and B (4), were obtained from the fruits of Illicium lanceolatum, along with four known prenylated C6 -C3 compounds (5-8). Their structures were proposed through HR-ESI-MS, 1 H, 13 C, and 2D NMR data interpretation. Moreover, the absolute configuration of 1 and 2 were further assigned by single-crystal X-ray diffraction analysis and electronic circular dichroism (ECD) calculations, respectively. Illihenryipyranol A (6) exhibited neuroprotective activity against MPP+ -induced PC12 cell damage in a dose-dependent manner.


Assuntos
Illicium/química , Fármacos Neuroprotetores/química , Sesquiterpenos/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Frutas/química , Frutas/metabolismo , Illicium/metabolismo , Espectroscopia de Ressonância Magnética , Conformação Molecular , Fármacos Neuroprotetores/isolamento & purificação , Fármacos Neuroprotetores/farmacologia , Células PC12 , Extratos Vegetais/química , Prenilação , Ratos , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Espectrometria de Massas por Ionização por Electrospray
14.
Chem Biodivers ; 19(9): e202200618, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35972824

RESUMO

Three rare spirocyclohexadienone-type neolignans, magnoflorins A-C (1-3), and three known analogs (4-6), were isolated from the leaves of Magnolia liliiflora. Magnoflorin D (4) was obtained from natural resources for the first time. The chemical structures and absolute configurations of 1-4 were elucidated through detailed analysis of HR-ESI-MS, IR, 1 H, 13 C, and 2D NMR, and ECD experiments. The absolute configuration of 5 were characterized by X-ray crystallography in present study. Moreover, compounds 4 and 5 displayed moderate neuroprotective activity against corticosterone-induced PC12 cells injury at 20 µM with cell viability of 71.5±0.99 % and 73.0±1.42 %, respectively, compared to the model group with 60.83±0.93 %. Compound 6 could enhance neurite outgrowth of nerve growth factor (NGF)-induced PC12 cells at 10 µM with the differentiation rate of 11.98 %, compared with 20.49 % of 50 ng/ml NGF.


Assuntos
Lignanas , Magnolia , Animais , Corticosterona/metabolismo , Lignanas/metabolismo , Lignanas/farmacologia , Magnolia/química , Fator de Crescimento Neural/metabolismo , Neuritos/metabolismo , Crescimento Neuronal , Células PC12 , Ratos
15.
Environ Sci Technol ; 55(24): 16586-16596, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34723492

RESUMO

Mainstream anaerobic wastewater treatment has received increasing attention for the recovery of methane-rich biogas from biodegradable organics, but subsequent mainstream nitrogen and dissolved methane removal at low temperatures remains a critical challenge in practical applications. In this study, granular sludge coupling n-DAMO with Anammox was employed for mainstream nitrogen removal, and the dissolved methane removal potential of granular sludge at low temperatures was investigated. A stable nitrogen removal rate (0.94 kg N m-3 d-1 at 20 °C) was achieved with a high-level effluent quality (<3.0 mg TN L-1) in a lab-scale membrane granular sludge reactor (MGSR). With decreasing temperature, the nitrogen removal rate dropped to 0.55 kg N m-3 d-1 at 10 °C, while the effluent concentration remained <1.0 mg TN L-1. The granular sludge with an average diameter of 1.8 mm proved to retain sufficient biomass (27 g VSS L-1), which enabled n-DAMO and Anammox activity at a hydraulic retention time as low as 2.16 h even at 10 °C. 16S rRNA gene sequencing and scanning electron microscopy revealed a stable community composition and compact structure of granular sludge during long-term operation. Energy recovery could be maximized by recovering most of the dissolved methane in mainstream anaerobic effluent, as only a small amount of dissolved methane was capable of supporting denitrifying methanotrophs in granular sludge, which enabled high-level nitrogen removal.


Assuntos
Compostos de Amônio , Metano , Oxidação Anaeróbia da Amônia , Anaerobiose , Reatores Biológicos , Desnitrificação , Nitrogênio , Oxirredução , RNA Ribossômico 16S/genética , Esgotos , Temperatura
16.
Environ Sci Technol ; 55(2): 1197-1208, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33185425

RESUMO

Nitrate/nitrite-dependent anaerobic methane oxidation (n-DAMO) is critical for mitigating methane emission and returning reactive nitrogen to the atmosphere. The genomes of n-DAMO archaea show that they have the potential to couple anaerobic oxidation of methane to dissimilatory nitrate reduction to ammonium (DNRA). However, physiological details of DNRA for n-DAMO archaea were not reported yet. This work demonstrated n-DAMO archaea coupling the anaerobic oxidation of methane to DNRA, which fueled Anammox in a methane-fed membrane biofilm reactor with nitrate as only electron acceptor. Microelectrode analysis revealed that ammonium accumulated where nitrite built up in the biofilm. Ammonium production and significant upregulation of gene expression for DNRA were detected in suspended n-DAMO culture with nitrite exposure, indicating that nitrite triggered DNRA by n-DAMO archaea. 15N-labeling batch experiments revealed that n-DAMO archaea produced ammonium from nitrate rather than from external nitrite. Localized gradients of nitrite produced by n-DAMO archaea in biofilms induced ammonium production via the DNRA process, which promoted nitrite consumption by Anammox bacteria and in turn helped n-DAMO archaea resist stress from nitrite. As biofilms predominate in various ecosystems, anaerobic oxidation of methane coupled with DNRA could be an important link between the global carbon and nitrogen cycles that should be investigated in future research.


Assuntos
Compostos de Amônio , Anaerobiose , Reatores Biológicos , Desnitrificação , Ecossistema , Metano , Nitratos , Nitritos , Oxirredução
17.
Bioorg Chem ; 112: 104963, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33991836

RESUMO

Pseudolaric acid A (PAA), one of the main bioactive ingredients in traditional medicine Pseudolarix cortex, exhibits remarkable anticancer activities. Yet its mechanism of action and molecular target have not been investigated and remain unclear. In this work, mechanistic study showed that PAA induced cell cycle arrest at G2/M phase and promoted cell death through caspase-8/caspase-3 pathway, demonstrating potent antiproliferation and anticancer activities. PAA was discovered to be a new Hsp90 inhibitor and multiple biophysical experiments confirmed that PAA directly bind to Hsp90. Active PAA-probe was designed, synthesized and biological evaluated. It was subsequently employed to verify the cellular interaction with Hsp90 in HeLa cells through photoaffinity labeling approach. Furthermore, NMR experiments showed that N-terminal domain of Hsp90 and essential groups in PAA are important for the protein-inhibitor recognition. Structure-activity relationship studies revealed the correlation between its Hsp90 inhibitory activity with anticancer activity. This work proposed a potential mechanism involved with the anticancer activity of PAA and will improve the appreciation of PAA as a potential cancer therapy candidate.


Assuntos
Antineoplásicos/farmacologia , Diterpenos/farmacologia , Descoberta de Drogas , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Diterpenos/síntese química , Diterpenos/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Choque Térmico HSP90/isolamento & purificação , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Células Tumorais Cultivadas
18.
Environ Res ; 198: 111221, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33971131

RESUMO

The difficulty and long duration of start-up wastes numerous costs, labors and time and a little fluctuate during the process might fail it. However, studies dealing with the problem hindering accelerated start-up are still insufficient. Current research focused to develop a method for accelerated start-up in an efficient way. This work outlined a novel alternative for accelerated start-up. This joint method, adding waste effluent with applying biofilm reactor, could successfully start up hydrogen production in the first 24 h via increasing ability of hydrogen producers while the control group produced little hydrogen. The two factors, biofilm formation and addition of waste effluent, expressed the combined effects on accelerated start-up. This study suggested that little molecules like quorum sensing system factors and indoles might be the crucial regulating and stimulating factors and express the accelerated start-up ability only in biofilm reactors.


Assuntos
Biofilmes , Eliminação de Resíduos Líquidos , Reatores Biológicos , Fermentação , Hidrogênio , Percepção de Quorum
19.
Environ Res ; 193: 110533, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33285154

RESUMO

Combining nitrate/nitrite dependent anaerobic methane oxidation (n-DAMO) and anaerobic ammonium oxidation (Anammox) is a promising sustainable wastewater treatment technology, which simultaneously achieve nitrogen removal and methane emission mitigation. However, the practical application of n-DAMO has been greatly limited by its extremely slow growth-rate and low reaction rate. This work proposes an innovative Membrane BioTrickling Filter (MBTF), which consist of hollow fiber membrane for effective methane supplementation and polyurethane sponge as support media for the attachment and growth of biofilm coupling n-DAMO with Anammox. When steady state with a hydraulic retention time (HRT) of 6.00 h was reached, above 99.9% of nitrogen was removed from synthetic sidestream wastewater at a rate of 3.99 g N L-1 d-1. This system presented robust capacity to withstand unstable partial nitritation effluent, achieving complete nitrogen removal at a varied nitrite to ammonium ratio in the range of 1.10-1.40. It is confirmed that n-DAMO and Anammox microorganisms jointly dominated the microbial community by pyrosequencing technology. The complete nitrogen removal potential at high-rate and efficient biomass retention (12.4 g VSS L-1) of MBTF offers promising alternative for sustainable wastewater treatment by the combination of n-DAMO and Anammox.


Assuntos
Compostos de Amônio , Metano , Anaerobiose , Reatores Biológicos , Desnitrificação , Nitratos , Nitritos , Nitrogênio , Oxirredução
20.
Environ Res ; 192: 110282, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33038361

RESUMO

Sulfate dependent ammonium oxidation (Sulfammox) is a potential microbial process coupling ammonium oxidation with sulfate reduction under anaerobic conditions, which provides a novel link between nitrogen and sulfur cycle. Recently, Sulfammox was detected in wastewater treatments and was confirmed to occur in natural environments, especially in marine sediments. However, knowledge gaps in the mechanism of Sulfammox, functional bacteria, and their metabolic pathway, make it challenging to estimate its environmental significance and potential applications. This review provides an overview of recent advances in Sulfammox, including possible mechanisms, functional bacteria, and main influential factors, and discusses future challenges and opportunities. Future perspectives are outlined and discussed, such as exploration of microbial community structure and metabolic pathways, possible interactions with other microbes, environmental significance, and potential applications for nitrogen and sulfate removal, to inspire more researches on the Sulfammox process.


Assuntos
Compostos de Amônio , Anaerobiose , Reatores Biológicos , Nitrogênio , Oxirredução , Sulfatos , Enxofre
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