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1.
Bioresour Technol ; 343: 126116, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34653622

RESUMO

A heterotrophic nitrification- aerobic denitrification (HNAD) bacterium, Acinetobacter junii ZHG-1, was isolated, meanwhile, the optimal conditions for the strain were evaluated, moreover, the influence mechanism of the C/N ratio on the HNAD process was investigated from the perspective of electron transport and energy level. The increasing of C/N ratio enhanced the reduced/oxidized nicotinamide adenine dinucleotide (NADH/NAD+) ratio, NADH concentration, electron transport system activity (ETSA), ATP content, as well as enzymes activities, consequently, the HNAD performance of the strain can be improved, however, when the C/N ratio was higher than 30, the activities of enzymes relating to the HNAD process and the ETSA had reached the maximum, which might limit the further improvement of the nitrogen removal with the increasing of C/N ratio. As the interaction between different biochemical reactions in HNAD process, more efforts should be devoted to the influent mechanism of different environmental factors on the HNAD process.


Assuntos
Desnitrificação , Nitrificação , Acinetobacter , Aerobiose , Processos Heterotróficos , Nitritos , Nitrogênio
2.
Sci Total Environ ; 805: 150212, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34536867

RESUMO

The traditional biological nitrogen removal (BNR) follows the conventional scheme of sequential nitrification and denitrification. In recent years, novel processes such as anaerobic ammonia oxidation (anammox), complete oxidation of ammonia to nitrate in one organism (comammox), heterotrophic nitrification and aerobic denitrification (HN-AD), and dissimilatory nitrate reduction to ammonium (DNRA) are gaining tremendous attention after the discovery of metabolically versatile bacteria. Among them, HN-AD offers several advantages because individual bacteria could achieve one-stage nitrogen removal under aerobic conditions in the presence of organic carbon. In this review, besides classical BNR processes, we summarized the existing literature on HN-AD bacteria which have been isolated from diverse habitats. A particular focus was given on the diversity and physiology of HN-AD bacteria, influences of physiological and biochemical factors on their growth, nitrogen removal performances, as well as limitations and strategies in unraveling HN-AD metabolic pathways. We also presented case studies of HN-AD application in wastewater treatment facilities, pointed out forthcoming challenges of HN-AD in these systems, and presented modulation strategies for HN-AD application in engineering. This review may help improve the existing design of wastewater treatment plants by harnessing HN-AD bacteria for effective nitrogen removal.


Assuntos
Nitrificação , Purificação da Água , Aerobiose , Desnitrificação , Processos Heterotróficos , Nitrogênio/análise , Águas Residuárias
3.
Chemosphere ; 286(Pt 2): 131637, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34340113

RESUMO

Quantitative image analysis (QIA) was used for monitoring the morphology of activated sludge (AS) during a granulation process and, thus, to define and quantify, unequivocally, structural changes in microbial aggregates correlated with the sludge properties and granulation rates. Two sequencing batch reactors fed with acetate at organic loading rates of 1.1 ± 0.6 kgCOD m-3 d-1 (R1) and 2.0 ± 0.2 kgCOD m-3 d-1 (R2) and three minimal imposed sludge settling velocities (0.27 m h-1, 0.53 m h-1, and 5.3 m h-1) induced distinct granulation processes and rates. QIA results evidenced the turning point from flocculation to granulation processes by revealing the differences in the aggregates' stratification patterns and quantifying the morphology of aggregates with equivalent diameter (Deq) of 200 µm ≤ Deq ≤ 650 µm. Multivariate statistical analysis of the QIA data allowed to distinguish the granulation status in both systems, by clustering the observations according to the sludge aggregation and granules maturation status, and successfully predicting the sludge volume index measured at 5 min (SVI5) and 30 min (SVI30). These results evidence the possibility of defining unequivocally the granulation rate and anticipating the sludge settling properties at early stages of the process using QIA data. Hence, QIA could be used to predict episodes of granules disruption and hindered settling ability in aerobic granulation sludge processes.


Assuntos
Reatores Biológicos , Esgotos , Aerobiose , Floculação , Eliminação de Resíduos Líquidos
4.
Water Sci Technol ; 84(9): 2113-2130, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34810301

RESUMO

Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategies for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.


Assuntos
Esgotos , Águas Residuárias , Aerobiose , Reatores Biológicos , Eliminação de Resíduos Líquidos
5.
J Environ Sci (China) ; 109: 135-147, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34607662

RESUMO

Effective cultivation of stable aerobic granular sludge (AGS) is a crucial step in the successful application of this technology, and the formation of AGS could be facilitated by some environmental stress conditions. Four identical sequencing batch reactors (SBRs) were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions (inorganic carbon source, temperature, N/COD). Although various superimposed conditions induced a significant difference in the size, settling velocity, mechanic strength of AGS, mature aerobic granules could be successfully obtained in all four reactors after 70 days' operation, indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation. Based on the results of redundancy analysis, the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function, while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS. In addition, superimposed stress conditions could result in the difference in the microbial population between four reactors, but the population diversity and abundance of microorganisms were not the determinants of AGS formation. This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.


Assuntos
Nitrogênio , Eliminação de Resíduos Líquidos , Aerobiose , Reatores Biológicos , Esgotos
6.
Sheng Wu Gong Cheng Xue Bao ; 37(10): 3505-3519, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34708607

RESUMO

Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to the advantages such as cost-effectiveness, process simplicity, and absence of secondary pollution. This review summarized the advances on biological denitrification processes in recent years according to the different physiological characteristics and denitrification mechanisms of denitrification microorganisms. The pros and cons of different biological denitrification processes developed based on nitrifying bacteria, denitrifying bacteria, and anaerobic ammonia-oxidizing bacteria were compared with the aim to identify the best strategy for denitrification in a complex wastewater environment. The rapid development of synthetic biology provides possibilities to develop highly-efficient denitrifying strains based on mechanistic understandings. Combined with the applications of automatic simulation to obtain the optimal denitrification conditions, cost-effective and highly-efficient denitrification processed can be envisioned in the foreseeable future.


Assuntos
Desnitrificação , Nitrificação , Aerobiose , Nitrogênio , Águas Residuárias
7.
Sheng Wu Gong Cheng Xue Bao ; 37(10): 3685-3695, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34708620

RESUMO

Biological denitrification is the most widely used technology for nitrate removal in wastewater treatment. Conventional denitrification requires long hydraulic retention time, and the nitrate removal efficiency in winter is low due to the low temperature. Therefore, it is expected to develop new approaches to enhance the denitrification process. In this paper, the effect of adding different concentrations of Fe3O4 nanoparticles on the denitrification catalyzed by Pseudomonas stutzeri was investigated. The maximum specific degradation rate of nitrate nitrogen improved from 18.0 h⁻¹ to 23.7 h⁻¹ when the concentration of Fe3O4 increased from 0 mg/L to 4 000 mg/L. Total proteins and intracellular iron content also increased along with increasing the concentration of Fe3O4. RT-qPCR and label-free proteomics analyses showed that the relative expression level of denitrifying genes napA, narJ, nirB, norR, nosZ of P. stutzeri increased by 55.7%, 24.9%, 24.5%, 36.5%, 120% upon addition of Fe3O4, and that of denitrifying reductase Nap, Nar, Nir, Nor, Nos increased by 85.0%, 147%, 16.5%, 47.1%, 95.9%, respectively. No significant difference was observed on the relative expression level of denitrifying genes and denitrifying reductases between the bacteria suspended and the bacteria adhered to Fe3O4. Interestingly, the relative expression level of electron transfer proteins of bacteria adhered to Fe3O4 was higher than that of the bacteria suspended. The results indicated that Fe3O4 promoted cell growth and metabolism through direct contact with bacteria, thereby improving the denitrification. These findings may provide theoretical support for the development of enhanced denitrification.


Assuntos
Pseudomonas stutzeri , Aerobiose , Desnitrificação , Nitratos , Nitrogênio , Pseudomonas stutzeri/genética
8.
Water Res ; 206: 117753, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34688097

RESUMO

Calcium phosphate could be accumulated in aerobic granules, which attracts attention recently for phosphorus removal and recovery from wastewater. In this study, partial nitrifying granules with high calcium precipitate content were sorted into different size groups for characterization and evaluation to reveal the dynamic balance of granules at stead state and relevant calcium phosphate precipitation and accumulation mechanism. It was found that light yellow small granules without calcium precipitates but high microbial activity co-existed with deep brown granules with calcium precipitate of around 91% and low microbial activity. Characterization with specific oxygen uptake rates, specific ammonium oxidation rates, calcium and phosphate removal rates from solution, EPS contents, elemental compositions by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and scanning electron microscopy (SEM) for different size groups of granules enabled a proposal of a new hypothesized mechanism for calcium precipitation and accumulation. With this proposed mechanism, it is believed that sufficient granule retention time in reactors was critical for the accumulation of calcium precipitates followed by a slow microbial growth rate of biomass due to mass transfer resistance. The co-precipitation of calcium carbonate and calcium phosphate mainly occurred in granules with a size less than 710 µm while calcium phosphate dominant minerals were accumulated in granules larger than 710 µm. The results and conclusions in this study shed light on the mechanisms of calcium phosphate accumulation in granules, which could be used to better operate and control aerobic granular sludge with calcium phosphates for phosphorus removal and recovery.


Assuntos
Reatores Biológicos , Esgotos , Aerobiose , Fosfatos de Cálcio
9.
Bioresour Technol ; 341: 125839, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34523562

RESUMO

A Phanerochaete chrysosporium-based aerobic granular sludge (PC-AGS) was developed by inoculating fungal mycelial pellets into a lab-scale aerobic granular sequencing batch reactor (AGSBR). A strategy using step-anaerobic feeding coupled with multi A/O conditions was adopted. The results showed that the removal efficiencies for total phosphorus (TP) and total inorganic nitrogen (TIN) were 94.56 ± 2.92% and 75.20 ± 7.74%, respectively, under relatively low aeration time. Compared with original AGS, the content of extracellular proteins for PC-AGS obviously increased from 18.61 to 41.44 mg/g MLSS by the end of phase I. Moreover, the mature granules had a larger size and better stability during the 100 days operation. Furthermore, the analysis of microbial diversity detected many key functional groups in PC-AGS granules that were beneficial to nutrients removal. This work demonstrated that the addition of fungal pellets not only enhanced the removal performance, but also improved the stability of the AGS system.


Assuntos
Phanerochaete , Esgotos , Aerobiose , Reatores Biológicos , Nitrogênio , Nutrientes , Fósforo , Eliminação de Resíduos Líquidos
10.
J Environ Manage ; 299: 113641, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479150

RESUMO

Aerobic denitrifying bacteria have the potential to remove the co-pollutants Ni(II) and nitrate in industrial wastewater. In this study, aerobic denitrifying bacteria with significant Ni(II) removal efficiency was isolated from the biological reaction tank and named as Pseudomonas hibiscicola L1 strain after 16 S rRNA identification analysis. The removal of ever-increasing Ni(II) and NO3--N wastewater under aerobic conditions by strain L1 was discussed. The experimental results showed that strain L1 removed 84% of Ni(II) and 81% of COD, with the use of 34.8 mg L-1 of nitrogen source and without nitrite accumulation yet. Strain L1 had remarkable activity (OD600 = 0.51-0.56 (p < 0.05)) at 20 mg L-1 of Ni(II) and 100 mg L-1 of NO3--N. It was found that high Ni(II) gradients (2-10 mg L-1) had little effect on nitrate removal ratio (35-34% (p > 0.05), and the removal ratios of Ni(II) was enhanced (from 42% to 83% (p < 0.05)) by increasing nitrate (25-100 mg L-1). Also, the results indicated that strain L1 could reduce Ni(II) and nitrate under different pH (6-9); electron donor-glucose, sodium acetate, sodium succinate and trisodium citrate; C/N (5-20) and coexisting ions (Cu(II) and Zn(II)). Notably, the nitrogen balance analysis showed 32.4% of TN was lost nitrogen and 19.7% of TN was assimilated for cell growth, which indicated aerobic denitrification process of strain L1. Meanwhile, characterization technology (SEM, FTIR, and XRD) showed Ni(II) was bioadsorbed in the form of Ni(NH2)2, NiCO3, and Ni(OH)2·2H2O through surface functional groups. This research provides new microbial method for the simultaneous removal of nitrate and Ni(II) in wastewater.


Assuntos
Desnitrificação , Nitratos , Aerobiose , Nitrificação , Nitritos , Nitrogênio , Pseudomonas/genética , Stenotrophomonas
11.
Biomed Res Int ; 2021: 6620574, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34337038

RESUMO

In this study, 16S rRNA high-throughput sequencing technology was used to analyze the composition and diversity of bacterial and fungal communities in mushroom residue samples at different composting stages. During the composting process, the maximum temperature in the center of the pile can reach 52.4°C, and the temperature above 50°C has been maintained for about 8 days. The results showed that Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes, and Chloroflexi were the main microorganisms in the composting process, accounting for 98.9%-99.7% of the total bacteria. Furthermore, in order to obtain the protein expressed in each stage of composting, the nonstandard quantitative method (label free) was used to analyze it quantitatively by mass spectrometry, anda total of 22815 proteins were identified. It indicated that the number of identified proteins related to cellulose decomposition and the number of differentially expressed proteins were significantly enriched, and the functional proteins related to cellulose decomposition had significant stage correspondence.


Assuntos
Agaricales/metabolismo , Microbiota , Aerobiose , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Celulose/metabolismo , Compostagem , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Peptídeos/metabolismo , Proteômica , Temperatura
12.
J Environ Manage ; 298: 113521, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34392097

RESUMO

Extracellular polymeric substances (EPS) have a critical contribution to the stability of aerobic granular sludge (AGS), but the mechanism and details of EPS composition and function are far from clear. This work investigated the contribution of exopolysaccharide (PS) to maintaining the structural stability of AGS. The results revealed that PS hydrolysis induced by α-amylase, dextranase and cellulase significantly decreased the granular stability, whereas a substantial content reduction of extracellular protein (PN) was also observed. It was also found that hydrolysis of PS led to a decrease of sludge hydrophobicity, granular gel mechanical strength by 14.09 %, 38.67 %, respectively, and an increase of surface free energy by 49.59 %, which is not conducive to granular stability. Through fluorescent staining, existence of large amounts of PS and PN conjugates in EPS matrix was verified. It was proposed that these conjugates with PS as skeleton (PS-PN) dominate granular stability by affecting hydrophobicity interactions and hydrogen bonds system, which are two important parameters to gel properties, constituting a crucial finding of this work. This study offers an supplementation of EPS system theory and granular stability mechanism.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Aerobiose , Reatores Biológicos , Matriz Extracelular de Substâncias Poliméricas
13.
Viruses ; 13(7)2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34372580

RESUMO

Most of the defective/non-infectious enteric phages and viruses that end up in wastewater originate in human feces. Some of the causes of this high level of inactivity at the host stage are unknown. There is a significant gap between how enteric phages are environmentally transmitted and how we might design molecular tools that would only detect infectious ones. Thus, there is a need to explain the low proportion of infectious viral particles once replicated. By analyzing lysis plaque content, we were able to confirm that, under aerobic conditions, Escherichia coli produce low numbers of infectious MS2 phages (I) than the total number of phages indicated by the genome copies (G) with an I/G ratio of around 2%. Anaerobic conditions of replication and ROS inhibition increase the I/G ratio to 8 and 25%, respectively. These data cannot only be explained by variations in the total numbers of MS2 phages produced or in the metabolism of E. coli. We therefore suggest that oxidative damage impacts the molecular replication and assembly of MS2 phages.


Assuntos
Anaerobiose/fisiologia , Levivirus/metabolismo , Replicação Viral/fisiologia , Aerobiose/fisiologia , Colífagos/genética , Escherichia coli/metabolismo , Escherichia coli/virologia , Proteínas de Escherichia coli/metabolismo , Fezes/virologia , Humanos , Levivirus/patogenicidade , Espécies Reativas de Oxigênio/metabolismo , Virulência
14.
J Dairy Sci ; 104(10): 10678-10698, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34334198

RESUMO

We evaluated the ability of an inoculant containing a combination of Lactobacillus hilgardii and Lactobacillus buchneri to modify the microbiome and improve the aerobic stability of whole-plant corn silage after various lengths of ensiling. Chopped whole-plant corn at about 33% dry matter (DM) was uninoculated (CTR) or inoculated with L. hilgardii CNCM I-4785 and L. buchneri NCIMB 40788 at 200,000 cfu/g of fresh forage weight each (combined application rate of 400,000 cfu of lactic acid bacteria/g of fresh forage weight; LHLB), L. buchneri NCIMB 40788 at 400,000 cfu/g of fresh forage weight and Pediococcus pentosaceus NCIMB 12455 at 100,000 cfu/g of fresh forage weight, used as a positive control (LB500), L. hilgardii CNCM I-4785 at the application rate used in the LHLB formulation of 200,000 cfu/g of fresh forage weight (LH), or L. buchneri NCIMB 40788 at the application rate used in the LHLB formulation of 200,000 cfu/g of fresh forage weight (LB). Silos were opened after 34 and 99 d of ensiling and analyzed for nutrient composition, fermentation profile, microbiome, and aerobic stability. After 34 d of ensiling, the inoculated silages had greater numbers of culturable lactic acid bacteria, a bacterial community less rich and diverse, greater relative abundance of Lactobacillus, lower relative abundance of Klebsiella, and a greater concentration of propionic acid than uninoculated silages. Inoculation decreased the ratio of lactic acid to acetic acid, except for LB alone. Treatment LHLB resulted in silage with a greater concentration of 1,2-propanediol than LB500 and was the only treatment to have a lower relative abundance of Saccharomycetes compared with uninoculated silage. Treatments LHLB and LB500 improved the aerobic stability compared with CTR, but the individual LH and LB treatments applied at a low dose did not. Whereas LB500 was stable 34 h longer than CTR, LHLB was stable 91 h longer. After 99 d of ensiling, all inoculated silages had markedly greater aerobic stability than uninoculated silage and were stable for more than 360 h. The inoculant containing a combination of L. hilgardii and L. buchneri markedly improved the aerobic stability of corn silage after a relatively short period of ensiling, and such improvements were greater than the ones obtained from inoculation with the combination of L. buchneri and P. pentosaceus. Inoculating with the combination of L. hilgardii and L. buchneri may be helpful to producers that must feed silage shortly after ensiling.


Assuntos
Microbiota , Silagem , Aerobiose , Animais , Fermentação , Lactobacillus , Silagem/análise , Zea mays
15.
Bioresour Technol ; 341: 125785, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34455248

RESUMO

The nitrogen metabolic pathways of Pseudomonas taiwanensis J488 have not been confirmed from genomic function analysis and its divalent metal ion resistance remains poorly understood. In this study, the key denitrifying gene of Pseudomonas taiwanensis J488, nirB, was determined by draft genome sequencing. The nitrification of ammonium was insensitive to high concentrations of Ca(II), Mn(II), Zn(II), and Cd(II). Similarly, complete nitrite removal was achieved despite Mn(II) and Zn(II) reaching concentrations up to 30 mg/L. Furthermore, the efficiency of nitrate removal was significantly enhanced by 1.33%, 3.33%, 5.99%, and 1.53% with the addition of 0.5 mg/L Ca(II), 20 mg/L Mn(II), 5 mg/L Zn(II), and 2 mg/L Cd(II), respectively, comparison with the control. The bacterial growth in both nitrifying and denitrifying processes was substantially promoted by various dosages of divalent metal ions. These results indicate that divalent metal ions would not severely limit the capacity of strain J488 to purify nitrogen-polluted wastewater.


Assuntos
Compostos de Amônio , Hipotermia , Aerobiose , Desnitrificação , Processos Heterotróficos , Humanos , Nitrificação , Nitritos , Nitrogênio , Pseudomonas , Águas Residuárias
16.
Bioresour Technol ; 341: 125818, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34455251

RESUMO

Biotreatment of hypersaline wastewater requires robust strains with high resistance to activity inhibition and even bacterium death, which remains a worldwide challenge. Here Halomonas salifodinae, a simultaneous nitrification and denitrification (SND) bacterium, was isolated by performing repeated-batch acclimation, showing efficient nitrogen removal at 0-15% salinity and low activity inhibition prominently superior to that of other strains such as Pseudomonas sp. and Acinetobacter sp. Community analysis as well as comparison of microbial activity at different salinities revealed an increased relative abundance of halotolerant populations by stimulating their salt tolerance during the repeated-batch process. For single or mixed nitrogen sources at 15% salinity, the SND efficiencies of the isolated strain reached above 95%. The high activities were attributed to the key enzymes AMO and HAO for nitrification as well as NAP and NIR for denitrification. The findings provide a promising acclimation pathway to obtain robust bacteria for biotreatment of hypersaline wastewater.


Assuntos
Nitrificação , Águas Residuárias , Aclimatação , Aerobiose , Bactérias , Desnitrificação , Halomonas , Processos Heterotróficos , Nitrogênio
17.
Cancer Sci ; 112(11): 4543-4552, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34390075

RESUMO

Improving the chemotherapy resistance of temozolomide (TMZ) is of great significance in the treatment of glioblastoma multiforme (GBM). Long non-coding RNA just proximal to the X-inactive specific transcript (JPX) has been proven to be involved in cancer progression. However, the intrinsic significance and molecular mechanism by which JPX orchestrates GBM progression and TMZ chemotherapy resistance remain poorly understood. Here, JPX was found to be significantly elevated in GBM tissues and cell lines, and patients with high expressions of JPX showed significantly worse prognoses. Functional experiments revealed its carcinogenic roles in GBM cell proliferation, TMZ chemoresistance, anti-apoptosis, DNA damage repair, and aerobic glycolysis. Mechanistically, JPX formed a complex with phosphoinositide dependent kinase-1 (PDK1) messenger RNA (mRNA) and promoted its stability and expression. Furthermore, an RNA immunoprecipitation (RIP) experiment showed that JPX interacted with N6-methyladenosine (m6A) demethylase FTO alpha-ketoglutarate dependent dioxygenase (FTO) and enhanced FTO-mediated PDK1 mRNA demethylation. JPX exerted its GBM-promotion effects through the FTO/PDK1 axis. Taken together, these findings reveal the key role of JPX in promoting GBM aerobic glycolysis and TMZ chemoresistance in an m6A-dependent manner. Thus, it comprises a promising novel therapeutic target for GBM chemotherapy.


Assuntos
Antineoplásicos Alquilantes/farmacologia , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil/metabolismo , RNA Longo não Codificante/metabolismo , Temozolomida/farmacologia , Adenosina/análogos & derivados , Adenosina/metabolismo , Aerobiose , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Desmetilação , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/tratamento farmacológico , Glioblastoma/mortalidade , Glioblastoma/patologia , Glicólise , Humanos , Proteínas de Neoplasias/metabolismo , Prognóstico , RNA Mensageiro/metabolismo
18.
Sci Total Environ ; 801: 149319, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34428659

RESUMO

Traditional nitrogen removal relies on the autotrophic nitrification and anaerobic denitrification process. In the system, autotrophic microorganisms achieve nitrification under aerobic condition and heterotrophic microorganisms complete the denitrification in anaerobic condition. As the two types of microorganisms have different tolerance on oxygen concentration, nitrification and denitrification are normally set in two compartments for high nitrogen removal. Therefore, large land occupying is required. In fact, there is a special type of microorganism called heterotrophic nitrification & aerobic denitrification microorganisms (HNADMs) which can oxidize ammonium nitrogen, and perform denitrification in the presence of oxygen. HNADMs have been reported in many environments. It was found that HNADMs could simultaneously achieve nitrification and denitrification. In addition, some HNADMs not only have the ability to remove nitrogen, but also have the ability to remove phosphorus. It suggests that HNADMs have great potential for pollution removal from wastewater. So far, individual work on single strain was carried out. Comprehensive summary of the HNADMs would provide a better picture for understanding and directing its application. In this paper, the studies related on HNADMs were reviewed. The nitrogen metabolism pathway of HNADMs was summarized. The impact of pH, DO, carbon source, and C/N on HNADMs growth and metabolism were discussed. In addition, the extracellular polymeric substance (EPS) production, quorum sensing (QS) secretion and P removal by HNADMs were displayed.


Assuntos
Desnitrificação , Nitrificação , Aerobiose , Matriz Extracelular de Substâncias Poliméricas , Processos Heterotróficos , Nitritos , Nitrogênio , Águas Residuárias
19.
Int J Legal Med ; 135(6): 2555-2565, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34373945

RESUMO

A quite intriguing subject being intensively researched in the forensic toxicology field is the source of postmortem determined blood ethanol concentration: antemortem ingestion or postmortem microbial production. Our previous research on microbial ethanol production has reported a quantitative relationship between the ethanol and the higher alcohols and 1-butanol produced by Escherichia coli, Clostridium perfrigens, and Clostridium sporogenes. In this contribution, we continue our research reporting on the following: (i) the patterns of ethanol, higher alcohols, and 1-butanol production by the microbes Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (all being aerobic/facultative anaerobic species, common corpse's colonizers, and ethanol producers), under controlled laboratory conditions, (ii) the mathematical modeling, with simple mathematical equations, of the correlation between ethanol concentration and the other studied alcohols' concentrations, by performing multiple linear regression analysis of the results, and (iii) the applicability of the constructed models in microbial cultures developed under different temperature than that used to build the models, in denatured blood cultures and in real postmortem cases. The aforementioned alcohols were proved to be all indicators of ethanol production, both in qualitative and quantitative terms. 1-Propanol was the most significant alcohol in modeling microbial ethanol production, followed by methyl-butanol. The K. pneumoniae's models achieved the best scoring in applicability (E < 40%) compared to the S. aureus and E. faecalis models, both at laboratory microbial cultures at 37 °C and real postmortem cases. Overall, a noteworthy accuracy in estimating the microbial ethanol in cultures and autopsy blood is achieved by the employed simple linear models.


Assuntos
Sangue/microbiologia , Enterococcus faecalis/química , Etanol/análise , Klebsiella pneumoniae/química , Staphylococcus aureus/química , 1-Butanol/análise , 1-Propanol/análise , Aerobiose , Anaerobiose , Autopsia , Concentração Alcoólica no Sangue , Butanóis/análise , Humanos , Modelos Teóricos , Pentanóis/análise
20.
Methods Mol Biol ; 2341: 103-116, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264466

RESUMO

Developments in mass spectrometry have made it possible to identify individual biomolecules in complex samples. This has led to advances in the detection and quantification of both extracellular and intracellular metabolites, such as amino acids, organic acids, fatty acids, nucleotides, and CoA-esters from growth media and cellular extracts. However, the reproducibility of metabolite data can be problematic if the concentrations and/or stability of metabolites fluctuate during culture harvesting and processing. Herein we describe a standardized and efficient collection protocol and best practices for preservation and harvesting of Staphylococcus aureus cellular and supernatant samples to improve reproducibility, reliability, and consistency in mass-spectrometry-based metabolite data sets.


Assuntos
Metabolômica/métodos , Staphylococcus aureus/crescimento & desenvolvimento , Aerobiose , Guias como Assunto , Espectrometria de Massas , Staphylococcus aureus/metabolismo
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