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1.
J Environ Manage ; 366: 121877, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39018860

RESUMEN

Sulfur-driven autotrophic denitrification (S0dAD) was employed to remove residual nitrogen from the biological effluent of landfill leachate after partial nitrification and denitrification pretreatment. The performance of S0dAD were assessed with various NOx--N (NO2--N and NO3--N) loadings over a 185-day operational period. The results demonstrated that a notable NOx--N removal efficiency of 97.8 ± 2.0% was achieved under nitrogen removal rates of 0.12 ± 0.02 kg N/(m3· d), leading to total nitrogen concentrations of 8.6 ± 3.8 mg/L in the effluent. Batch experiments revealed competitive utilization of nitrogenous electron acceptors, with NO2--N demonstrating 2-4 times higher denitrification rates than NO3--N under coexistence conditions. Genus-level microbial community identified that Thiobacillus and Sulfurovum was highly enriched with as key denitrifying bacteria in the S0dAD system. These findings provide insights for advanced nitrogen removal coupling S0dAD with partial nitrification and denitrification process for landfill leachate treatment.

2.
Artículo en Chino | MEDLINE | ID: mdl-38858110

RESUMEN

Objective:To investigate the differences in the therapeutic effects of endoscopic surgery combined with chemotherapy and endoscopic surgery combined with radiotherapy in the treatment of early nasopharyngeal carcinoma, and to select individualized treatment strategy for early nasopharyngeal carcinoma. Methods:The clinical data of 68 patients with early nasopharyngeal carcinoma(T1-2N0M0) who received surgical treatment in a high-incidence area were retrospectively analyzed. According to different treatment methods, they were divided into the surgery + chemotherapy group(n=34, treated with endoscopic surgery combined with chemotherapy) and the surgery + radiotherapy group(n=34, treated with endoscopic surgery combined with radiotherapy). Propensity score matching was used to match the patient data between the two groups at a 1∶1 ratio. Patients were followed up, and the survival rates and hematological toxicities were compared between the two groups. Results:Twenty-four cases in the surgery + chemotherapy group and 24 cases in the surgery + radiotherapy group were successfully matched. After matching, there was no statistically significant difference in T stage, and clinical stage between the two groups(all P>0.05). The 3-year OS and DFS in the surgery + chemotherapy group were 100.0% and 95.8%, respectively, while the 3-year OS and DFS in the surgery + radiotherapy group were 100.0% and 100.0%, respectively, with no significant difference in survival rates between the two groups(both P>0.05). After treatment, there was no statistically significant difference in bone marrow suppression between the surgery + chemotherapy group and the surgery + radiotherapy group (all P> 0.05) Conclusion:Endoscopic surgery combined with chemotherapy and surgery combined with radiotherapy have comparable clinical efficacy in the treatment of early nasopharyngeal carcinoma, but without radiotherapy-related complications, which is worth further investigation.


Asunto(s)
Carcinoma , Endoscopía , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Humanos , Neoplasias Nasofaríngeas/terapia , Neoplasias Nasofaríngeas/radioterapia , Carcinoma Nasofaríngeo/terapia , Carcinoma Nasofaríngeo/radioterapia , Estudios Retrospectivos , Masculino , Pronóstico , Femenino , Terapia Combinada , Carcinoma/terapia , Tasa de Supervivencia , Persona de Mediana Edad , Estadificación de Neoplasias , Incidencia , Resultado del Tratamiento , Adulto
3.
Brain Behav Immun ; 120: 499-512, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38944162

RESUMEN

The gut microbiota and neurological development of neonatal mice are susceptible to environmental factors that may lead to altered behavior into adulthood. However, the role that changed gut microbiota and neurodevelopment early in life play in this needs to be clarified. In this study, by modeling early-life environmental changes by cross-fostering BALB/c mice, we revealed the effects of the environment during the critical period of postnatal development on adult social behavior and their relationship with the gut microbiota and the nervous system. The neural projections exist between the ascending colon and oxytocin neurons in the paraventricular nuclei (PVN), peripheral oxytocin levels and PVN neuron numbers decreased after cross-fostering, and sex-specific alteration in gut microbiota and its metabolites may be involved in social impairments and immune imbalances brought by cross-fostering via the gut-brain axis. Our findings also suggest that social cognitive impairment may result from a combination of PVN oxytocinergic neurons, gut microbiota, and metabolites.

4.
J Psychiatry Neurosci ; 49(3): E192-E207, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38816029

RESUMEN

BACKGROUND: Recent studies have identified empathy deficit as a core impairment and diagnostic criterion for people with autism spectrum disorders; however, the improvement of empathy focuses primarily on behavioural interventions without the target regulation. We sought to compare brain regions associated with empathy-like behaviours of fear and pain, and to explore the role of the oxytocin-oxytocin receptor system in fear empathy. METHODS: We used C57BL mice to establish 2 models of fear empathy and pain empathy. We employed immunofluorescence histochemical techniques to observe the expression of c-Fos throughout the entire brain and subsequently quantified the number of c-Fos-positive cells in different brain regions. Furthermore, we employed chemogenetic technology to selectively manipulate these neurons in Oxt-Cre-/+ mice to identify the role of oxytocin in this process. RESULTS: The regions activated by fear empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, paraventricular nucleus (PVN), lateral habenula, and ventral and dorsal hippocampus. The regions activated by pain empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, and lateral habenula. We found that increasing the activity of oxytocin neurons in the PVN region enhanced the response to fear empathy. This enhancement may be mediated through oxytocin receptors. LIMITATIONS: This study included only male animals, which restricts the broader interpretation of the findings. Further investigations on circuit function need to be conducted. CONCLUSION: The brain regions implicated in the regulation of fear and pain empathy exhibit distinctions; the activity of PVN neurons was positively correlated with empathic behaviour in mice. These findings highlight the role of the PVN oxytocin pathway in regulating fear empathy and suggest the importance of oxytocin signalling in mediating empathetic responses.


Asunto(s)
Empatía , Miedo , Ratones Endogámicos C57BL , Neuronas , Oxitocina , Núcleo Hipotalámico Paraventricular , Animales , Oxitocina/metabolismo , Masculino , Núcleo Hipotalámico Paraventricular/metabolismo , Miedo/fisiología , Empatía/fisiología , Neuronas/metabolismo , Ratones , Receptores de Oxitocina/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Dolor/fisiopatología , Dolor/psicología , Ratones Transgénicos
5.
Bioresour Technol ; 402: 130767, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38692373

RESUMEN

The study assessed the effect of salinity and lead (Pb(II)) on the anammox sludge for nitrogen removal from saline wastewater. Results showed decreased nitrogen removal and specific anammox activity (SAA) with elevated salinity and Pb(II). SAA reduced from 541.3 ± 4.3 mg N g-1 VSS d-1 at 0.5 mg/L Pb(II) to 436.0 ± 0.2 mg N g-1 VSS d-1 at 30 g/L NaCl, further to 303.6 ± 7.1 mg N g-1 VSS d-1 under 30 g/L NaCl + 0.5 mg/L Pb(II). Notably, the combined inhibition at salinity (15-20 g/L NaCl) and Pb(II) (0.3-0.4 mg/L) exhibited synergistic effect, while higher salinity and Pb(II) aligned with independent inhibition models. Combined inhibition decreased protein/polysaccharides ratio, indicating more severe negative effect on anammox aggregation capacity. Metagenomics confirmed decreased Candidatus Kuenenia, and enhanced denitrification under elevated salinity and Pb(II) conditions. This study offers insights into anammox operation for treating saline wastewater with heavy metals.


Asunto(s)
Plomo , Nitrógeno , Salinidad , Aguas Residuales , Aguas Residuales/química , Plomo/metabolismo , Nitrógeno/metabolismo , Purificación del Agua/métodos , Oxidación-Reducción , Aguas del Alcantarillado/microbiología , Anaerobiosis/efectos de los fármacos , Bacterias/metabolismo , Bacterias/efectos de los fármacos , Reactores Biológicos , Microbiota/efectos de los fármacos , Desnitrificación/efectos de los fármacos
6.
J Environ Manage ; 357: 120803, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38569268

RESUMEN

Resuscitation promoting factors (Rpfs), known for their anti-dormancy cytokine properties, have been extensively investigated in the medical field. Although the Rpf from Micrococcus luteus has been successfully utilized to resuscitate and stimulate microbial populations for the degradation of polychlorinated biphenyls (PCBs), the presence of indigenous Rpf homologs in PCB-contaminated soils has not been established. In this study, the distribution characteristics of rpf-like genes and indigenous strain capable of producing Rpf in PCB-contaminated soils were explored. The results revealed the widespread presence of Rpf-like domains and their associated genes, particularly in close association with heavy metals and PCBs. The rpf-like genes were predominantly found in Proteobacteria and displayed a positive correlation with genes involved in PCB degradation and viable but non-culturable (VBNC) formation. Notably, the recombinant Rpf-Ac protein derived from the indigenous strain Achromobacter sp. HR2 exhibited muralytic activity and demonstrated significant efficacy in resuscitating the growth of VBNC cells, while also stimulating the growth of normal cells. These findings shed light on the prevalent presence of Rpf homologs in PCB-contaminated soils and their potential to resuscitate functional populations in the VBNC state, thereby enhancing in situ bioremediation.


Asunto(s)
Bifenilos Policlorados , Biodegradación Ambiental , Suelo
7.
Dev Neurosci ; 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38583418

RESUMEN

INTRODUCTION: Transcription factor EB (TFEB), a key regulator of autophagy and lysosomal biogenesis, has diverse roles in various physiological processes. Enhancing lysosomal function by TFEB activation has recently been implicated in restoring neural stem cells (NSCs) function. Overexpression of TFEB can inhibit the cell cycle of newborn cortical NSCs. It has also been found that TFEB regulates the pluripotency transcriptional network in mouse embryonic stem cells independent of autophagy lysosomal biogenesis. This study aims to explore the effects of TFEB activation on neurogenesis in vivo through transgenic mice. METHODS: We developed a GFAP-driven TFEB overexpression mouse model (TFEB GoE) by crossing the floxed TFEB overexpression mice and hGFAP-cre mice. We performed immunohistochemical and fluorescence staining on brain tissue from newborn mice to assess neurogenesis changes, employing markers such as GFAP, Nestin, Ki67, DCX, Tbr1 and Neun to trace different stages of neural development and cell proliferation. RESULTS: TFEB GoE mice exhibited premature mortality, dying at 10-20 days after birth. Immunohistochemical analysis revealed significant abnormalities, including disrupted hippocampal structure and cortical layering. Compared to control mice, TFEB GoE mice showed a marked increase in radial glial cells (RGCs) in the hippocampus and cortex, with Ki67 staining indicating these cells were predominantly in a quiescent state. This suggests that TFEB overexpression suppresses RGCs proliferation. Additionally, abnormal distributions of migrating neurons and mature neurons were observed, highlighted by DCX, Tbr1 and Neun staining, indicating a disruption in normal neurogenesis. CONCLUSION: This study, using transgenic animals in vivo, revealed that GFAP-driven TFEB overexpression leads to abnormal neural layering in the hippocampus and cortex by dysregulating neurogenesis. Our study is the first to discover the detrimental impact of TFEB overexpression on neurogenesis during embryonic development, which has important reference significance in future TFEB overexpression interventions in NSCs for treatment.

8.
Biochem Biophys Res Commun ; 704: 149712, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38408414

RESUMEN

Astrocytes transfer extracellular functional mitochondria into neurons to rescue injured neurons after a stroke. However, there are no reports on drugs that interfere with intercellular mitochondrial transfer. Chrysophanol (CHR) was an effective drug for the treatment of cerebral ischemia-reperfusion injury (CIRI) and was selected as the test drug. The oxygen-glucose deprivation/reoxygenation (OGD/R) cell model and the middle cerebral artery occlusion animal model were established to investigate the effect of CHR on CIRI. The result showed that astrocytes could act as mitochondrial donors to ameliorate neuronal injury. Additionally, the neuroprotective effect of astrocytes was enhanced by CHR, the CHR improved the neuronal mitochondrial function, decreased the neurological deficit score and infarction volume, recovered cell morphology in ischemic penumbra. The mitochondrial fluorescence probe labeling technique has shown that the protective effect of CHR is associated with accelerated astrocytic mitochondrial transfer to neurons. The intercellular mitochondrial transfer may be an important way to ameliorate ischemic brain injury and be used as a key target for drug treatment.


Asunto(s)
Antraquinonas , Isquemia Encefálica , Daño por Reperfusión , Ratas , Animales , Isquemia Encefálica/metabolismo , Astrocitos/metabolismo , Daño por Reperfusión/metabolismo , Neuronas/metabolismo , Mitocondrias
9.
J Nutr Biochem ; 125: 109570, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38218348

RESUMEN

High salt diet (HSD) is a risk factor of hypertension and cardiovascular disease. Although clinical data do not clearly indicate the relationship between HSD and the prevalence of Alzheimer's disease (AD), animal experiments have shown that HSD can cause hyperphosphorylation of tau protein and cognition impairment. However, whether HSD can accelerate the progression of AD by damaging the function of neurovascular unit (NVU) in the brain is unclear. Here, we fed APP/PS1 mice (an AD model) or wild-type mice with HSD and found that the chronic HSD feeding increased the activity of enzymes related to tau phosphorylation, which led to tau hyperphosphorylation in the brain. HSD also aggravated the deposition of Aß42 in hippocampus and cortex in the APP/PS1 mice but not in the wild-type mice. Simultaneously, HSD caused the microglia proliferation, low expression of Aqp-4, and high expression of CD31 in the wild-type mice, which were accompanied with the loss of pericytes (PCs) and increase in blood brain barrier (BBB) permeability. As a result, wild-type mice fed with HSD performed poorly in Morris Water Maze and object recognition test. In the APP/PS1 mice, HSD feeding for 8 months worsen the cognition and accompanied the loss of PCs, the activation of glia, the increase in BBB permeability, and the acceleration of calcification in the brain. Our data suggested that HSD feeding induced the AD-like pathology in wild-type mice and aggravated the development of AD-like pathology in APP/PS1 mice, which implicated the tau hyperphosphorylation and NVU dysfunction.


Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Ratones Transgénicos , Proteínas tau/metabolismo , Dieta , Cognición , Cloruro de Sodio Dietético/efectos adversos , Modelos Animales de Enfermedad , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo
10.
Environ Pollut ; 344: 123320, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38185359

RESUMEN

The exploration of resuscitated strains, facilitated by the resuscitation promoting factor (Rpf), has substantially expanded the pool of cultivated degraders, enhancing the screening of bio-inoculants for bioremediation applications. However, it remains unknown whether these resuscitated strains can re-enter the viable but non-culturable (VBNC) state and the specific stress conditions that trigger such a transition. In this work, the whole genome, and polychlorinated biphenyl (PCB)-degrading capabilities of a resuscitated strain HR1, were investigated. Notably, the focus of this exploration was on elucidating whether HR1 would undergo a transition into the VBNC state when exposed to low temperature and PCBs, with and without the presence of heavy metals (HMs). The results suggested that the resuscitated strain Pseudomonas sp. HR1 harbored various functional genes related to xenobiotic biodegradation, demonstrating remarkable efficiency in Aroclor 1242 degradation and strong resistance against stress induced by low temperature and PCBs. Nevertheless, when exposed to the combined stress of low temperature, PCBs, and HMs, HR1 underwent a transition into the VBNC state. This transition was characterized by significant decreases in enzyme activities and notable changes in both morphological and physiological traits when compared to normal cells. Gene expression analysis revealed molecular shifts underlying the VBNC state, with down-regulated genes showed differential expression across multiple pathways and functions, including oxidative phosphorylation, glycolysis, tricarboxylic acid cycle, amino acid metabolism, translation and cytoplasm, while up-regulated genes predominantly associated with transcription regulation, membrane function, quorum sensing, and transporter activity. These findings highlighted the great potential of resuscitated strains as bio-inoculants in bioaugmentation and shed light on the survival mechanisms of functional strains under stressful conditions, which should be carefully considered during bioremediation processes.


Asunto(s)
Bifenilos Policlorados , Bifenilos Policlorados/toxicidad , Bifenilos Policlorados/metabolismo , Biodegradación Ambiental , Pseudomonas/genética , Pseudomonas/metabolismo , Frío , Fosforilación Oxidativa
11.
J Hazard Mater ; 465: 133242, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-38103289

RESUMEN

The resuscitated strains achieved through the addition of resuscitation promoting factor (Rpf) hold significant promise as bio-inoculants for enhancing the bioremediation of polychlorinated biphenyls (PCBs). Nevertheless, the potential of these resuscitated strains to transition into a viable but non-culturable (VBNC) state, along with the specific stressors that initiate this transformation, remains to be comprehensively elucidated. In this study, a resuscitated strain HR2, obtained through Rpf amendment, was employed to investigate its survival strategies under combined stress involving low temperature (LT), and PCBs, in the absence and presence of heavy metals (HMs). Whole-genome analysis demonstrated that HR2, affiliated with Achromobacter, possessed 107 genes associated with the degradation of polycyclic aromatic compounds. Remarkably, HR2 exhibited effective degradation of Aroclor 1242 and robust resistance to stress induced by LT and PCBs, while maintaining its culturability. However, when exposed to the combined stress of LT, PCBs, and HMs, HR2 entered the VBNC state. This state was characterized by significant decreases in enzyme activities and notable morphological, physiological, and molecular alterations compared to normal cells. These findings uncovered the survival status of resuscitated strains under stressful conditions, thereby offering valuable insights for the development of effective bioremediation strategies.


Asunto(s)
Bifenilos Policlorados , Compuestos Policíclicos , Bifenilos Policlorados/metabolismo , Biodegradación Ambiental
12.
World J Clin Cases ; 11(32): 7876-7880, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-38073692

RESUMEN

BACKGROUND: Primary pulmonary lymphoepithelioma-like carcinoma (PPLELC) is an uncommon subtype of squamous cell carcinoma (SCC) of the lung, closely associated with Epstein-Barr virus (EBV) infection. The pathological features of PPLELC closely resemble those of SCC, which makes it prone to misdiagnosis. Surgical intervention constitutes the primary treatment approach for PPLELC. CASE SUMMARY: This report describes a 44-year-old woman who was hospitalized for 1 mo due to left chest pain. Computed tomography revealed a mass shadow in the anterior basal segment of the left lower lobe, and a subsequent needle biopsy suggested SCC. The patient underwent radical tumor resection in the lower left lobe of the lung, and postoperative pathological examination indicated lymphoepithelial carcinoma, and the test for EBV encoded small RNA was positive. Following surgery, the patient was scheduled to receive four cycles of adjuvant chemotherapy, using the paclitaxel + carboplatin regimen, but the patient refused further treatment. CONCLUSION: PPLELC is an exceptionally rare subtype of lung SCC and is prone to misdiagnosis.

13.
J Environ Manage ; 347: 119073, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37776795

RESUMEN

The efficiency of microbial populations in degrading refractory pollutants and the impact of adverse environmental factors often presents challenges for the biological treatment of azo dyes. In this study, the genome analysis and azo dye Reactive Black 5 (RB5) degrading capability of a newly isolated strain, Shewanella sp. SR1, were investigated. By analyzing the genome, functional genes involved in dye degradation and mechanisms for adaptation to low-temperature and high-salinity conditions were identified in SR1. The addition of co-substrates, such as glucose and yeast extract, significantly enhanced RB5 decolorization efficiency, reaching up to 87.6%. Notably, SR1 demonstrated remarkable robustness towards a wide range of NaCl concentrations (1-30 g/L) and temperatures (10-30 °C), maintaining efficient decolorization and high biomass concentration. The metabolic pathways of RB5 degradation were deduced based on the metabolites and genes detected in the genome, in which the azo bond was first cleaved by FMN-dependent NADH-azoreductase and NAD(P)H-flavin reductase, followed by deamination, desulfonation, and hydroxylation mediated by various oxidoreductases. Importantly, the degradation metabolites exhibited reduced toxicity, as revealed by toxicity analysis. These findings highlighted the great potential of Shewanella sp. SR1 for bioremediation of wastewaters contaminated with azo dyes.


Asunto(s)
Compuestos Azo , Shewanella , Biodegradación Ambiental , Compuestos Azo/química , Shewanella/genética , Shewanella/metabolismo , Anaerobiosis , Colorantes/química
15.
Sci Total Environ ; 897: 165440, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37437637

RESUMEN

Microbial dechlorination of polychlorinated biphenyls (PCBs) is limited by the slow growth rate and low activity of dechlorinators. Resuscitation promoting factor (Rpf) of Micrococcus luteus, has been demonstrated to accelerate the enrichment of highly active PCB-dechlorinating cultures. However, it remains unclear whether the addition of Rpf can further improve the dechlorination performance of anaerobic dechlorination cultures. In this study, the effect of Rpf on the performance of TG4, an enriched PCB-dechlorinating culture obtained by Rpf amendment, for reductive dechlorination of four typical PCB congeners (PCBs 101, 118, 138, 180) was evaluated. The results indicated that Rpf significantly enhanced the dechlorination of the four PCB congeners, with residual mole percentages of PCBs 101, 118, 138 and 180 in Rpf-amended cultures being 16.2-29.31 %, 13.3-20.1 %, 11.9-14.4 % and 9.4-17.3 % lower than those in the corresponding cultures without Rpf amendment after 18 days of incubation. Different models were identified as appropriate for elucidating the dechlorination kinetics of distinct PCB congeners, and it was observed that the dechlorination rate constant is significantly influenced by the PCB concentration. The supplementing Rpf did not obviously change dechlorination metabolites, and the removal of chlorines occurred mainly at para- and meta- positions. Analysis of microbial community and functional gene abundance suggested that Rpf-amended cultures exhibited a significant enrichment of Dehalococcoides, Dehalogenimonas and Desulfitobacterium, as well as non-dechlorinators belonging to Desulfobacterota and Bacteroidetes. These findings highlight the potential of Rpf as an effective additive for enhancing PCB dechlorination, providing new insights into the survival of functional microorganisms involved in anaerobic reductive dechlorination.


Asunto(s)
Bifenilos Policlorados , Bifenilos Policlorados/metabolismo , Anaerobiosis , Biodegradación Ambiental , Cloro/metabolismo , Sedimentos Geológicos/microbiología
16.
Bioresour Technol ; 385: 129441, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37399961

RESUMEN

This study explores a novel approach for enhancing anaerobic digestion of waste activated sludge (WAS) through the combined pretreatment of fungal mash and free nitrous acid (FNA). Aspergillus PAD-2, a fungal strain with superior hydrolase secretion, was isolated from WAS and cultivated in-situ on food waste to produce fungal mash. The solubilization of WAS by fungal mash achieved a high soluble chemical oxygen demand release rate of 548 mg L-1 h-1 within first 3 h. The combined pretreatment of fungal mash and FNA further improved the sludge solubilization by 2-fold and resulted in a doubled methane production rate of 416±11 mL CH4 g-1 volatile solids. The Gompertz model analysis revealed a higher maximum specific methane production rate and shortened lag time by the combined pretreatment. These results demonstrate that the combined fungal mash and FNA pretreatment offers a promising alternative for fast anaerobic digestion of WAS.


Asunto(s)
Eliminación de Residuos , Aguas del Alcantarillado , Ácido Nitroso , Anaerobiosis , Metano , Alimentos , Eliminación de Residuos Líquidos/métodos , Reactores Biológicos
17.
J Environ Manage ; 339: 117961, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37075636

RESUMEN

Quorum quenching (QQ) has been demonstrated to be a novel technique for controlling biofouling in membrane bioreactors (MBRs), as it can significantly inhibit biofilm formation by disrupting quorum sensing (QS). The exploration of new QQ bacterial strains and the evaluation of their performance in mitigating membrane fouling in MBR systems is significant. In this study, an efficient QQ strain, Brucella sp. ZJ1 was encapsulated in alginate beads and evaluated for its ability to mitigate biofouling. The findings revealed that MBR with QQ beads extended the operation time by 2-3 times without affecting pollutant degradation. QQ beads maintained approximately 50% QQ activity after more than 50 days operation, indicating a long-lasting and endurable QQ effect. The QQ effect reduced extracellular polymeric substance (EPS) production especially in terms of polysaccharide and protein by more than 40%. QQ beads in the MBR also reduced the cake resistance and the irreversible resistance of membrane biofouling. Metagenomic sequencing suggests that QQ beads suppressed the QS effect and increased the abundance of QQ enzyme genes, ultimately inducing efficient membrane biofouling control.


Asunto(s)
Incrustaciones Biológicas , Brucella , Microbiota , Percepción de Quorum , Incrustaciones Biológicas/prevención & control , Matriz Extracelular de Sustancias Poliméricas , Reactores Biológicos/microbiología , Membranas Artificiales
19.
Appl Environ Microbiol ; 89(1): e0195122, 2023 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-36629425

RESUMEN

The anaerobic bioremediation of polychlorinated biphenyls (PCBs) is largely impeded by difficulties in massively enriching PCB dechlorinators in short periods of time. Tetrachloroethene (PCE) is often utilized as an alternative electron acceptor to preenrich PCB-dechlorinating bacteria. In this study, resuscitation promoting factor (Rpf) was used as an additive to enhance the enrichment of the microbial communities involved in PCE/PCBs dechlorination. The results indicated that Rpf accelerates PCE dechlorination 3.8 to 5.4 times faster than control cultures. In Aroclor 1260-fed cultures, the amendment of Rpf enables significantly more rapid and extensive dechlorination of PCBs. The residual high-chlorinated PCB congeners (≥5 Cl atoms) accounted for 36.7% and 59.8% in the Rpf-amended cultures and in the corresponding controls, respectively. This improvement was mainly attributed to the enhanced activity of the removal of meta-chlorines (47.7 mol % versus 14.7 mol %), which did not appear to affect dechlorination pathways. The dechlorinators, including Dehalococcoides in Chloroflexi and Desulfitobacterium in Firmicutes, were greatly enriched via Rpf amendment. The abundance of nondechlorinating populations, including Methanosarcina, Desulfovibrio, and Bacteroides, was also greatly enhanced via Rpf amendment. These results suggest that Rpf serves as an effective additive for the rapid enrichment of active dechlorinating cultures so as to provide a new approach by which to massively cultivate bioinoculants for accelerated in situ anaerobic bioremediation. IMPORTANCE The resuscitation promoting factor (Rpf) of Micrococcus luteus has been reported to resuscitate and stimulate the growth of functional microorganisms that are involved in the aerobic degradation of polychlorinated biphenyls (PCBs). However, few studies have been conducted to investigate the role of Rpf on anaerobic microbial populations. In this study, the enhancement of Rpf on the anaerobic microbial dechlorination of PCE/PCBs was discovered. Additionally, the Rpf-responsive populations underlying the enhanced dechlorination were uncovered. This report reveals the rapid enrichment of active dechlorinating cultures via Rpf amendment, and this sheds light on massively enriching PCB dechlorinators in short periods of time. The enhanced in situ anaerobic bioremediation of PCBs could be expected by supplementing Rpf.


Asunto(s)
Chloroflexi , Bifenilos Policlorados , Tetracloroetileno , Bifenilos Policlorados/metabolismo , Tetracloroetileno/metabolismo , Bacterias/metabolismo , Chloroflexi/metabolismo , Biodegradación Ambiental , Cloro/metabolismo , Sedimentos Geológicos/microbiología
20.
J Hazard Mater ; 447: 130781, 2023 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-36641851

RESUMEN

PCBs bioremediation is largely impeded by the reduced metabolic activity and degradation ability of indigenous and exogenous microorganisms. Resuscitation promoting factor (Rpf) of Micrococcus luteus, has been reported to resuscitate and stimulate the growth of PCB-degrading bacterial populations, and the resuscitated strains exhibited excellent PCB-degrading performances. Therefore, this study was conducted to assess the feasibility of supplementing Rpf (SR) or resuscitated strain LS1 (SL), or both (SRL) for enhanced bioremediation of PCB-contaminated soil. The results indicated that Rpf and/or LS1 amended soil microcosms achieved more rapid PCBs degradation, which were 1.1-3.2 times faster than control microcosms. Although soil-inoculated LS1 maintained the PCB-degrading activity, higher PCBs degradation was observed in Rpf-amended soil microcosms compared with SL. The order of enhancement effect on PCBs bioremediation was SRL > SR > SL. PCBs degradation in soil microcosms was via HOPDA-benzoate-catechol/protocatechuate pathways. The improved PCBs degradation in Rpf-amended soil microcosms was attributed to the enhanced abundances of PCB-degrading populations which were mainly belonged to Proteobacteria and Actinobacteria. These results suggest that Rpf and resuscitated strains serve as effective additive and bio-inoculant for enhanced bioremediation, providing new approaches to realizing large scale applications of in situ bioremediation.


Asunto(s)
Bifenilos Policlorados , Contaminantes del Suelo , Bifenilos Policlorados/análisis , Biodegradación Ambiental , Contaminantes del Suelo/metabolismo , Microbiología del Suelo , Bacterias/metabolismo , Suelo
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