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1.
Ecotoxicol Environ Saf ; 277: 116380, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38677068

RESUMEN

The interaction between microplastics (MPs) and cadmium (Cd) poses a threat to agricultural soil environments, and their effects on plant growth and rhizosphere microbial community functions are not yet clear. In this study, energy sorghum was used as a test plant to investigate the effects of two types of MPs, polystyrene (PS) and polyethylene (PE), at different particle sizes (13 µm, 550 µm) and concentrations (0.1%, 1% w/w), and Cd, as well as their interactions, on the growth of sorghum in a soil-cultivation pot experiment. The results showed that the combined effects of MP and Cd pollution on the dry weight and Cd accumulation rate in sorghum varied depending on the type, concentration, and particle size of the MPs, with an overall trend of increasing stress from combined pollution with increasing Cd content and accumulation. High-throughput sequencing analysis revealed that combined MP and Cd pollution increased bacterial diversity, and the most significant increase was observed in the abundance-based coverage estimator (ACE), Shannon, and Sobs indices in the 13 µm 1% PS+Cd treatment group. Metagenomic analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways revealed that 19 groups of metabolic pathways, including microbial metabolism and methane metabolism, differed significantly under combined MP and Cd pollution. Hierarchical clustering results indicated that Cd treatment and combined MP and Cd treatment affected the abundances of sorghum rhizosphere soil nitrogen (N) and phosphorus (P) cycling genes and that the type of MP present was an important factor affecting N and P cycling genes. The results of this study provide a basis for exploring the toxic effects of combined MP and Cd pollution and for conducting soil environmental risk assessments.


Asunto(s)
Cadmio , Microplásticos , Rizosfera , Microbiología del Suelo , Contaminantes del Suelo , Sorghum , Sorghum/efectos de los fármacos , Sorghum/microbiología , Cadmio/toxicidad , Contaminantes del Suelo/toxicidad , Microplásticos/toxicidad , Suelo/química , Tamaño de la Partícula , Bacterias/efectos de los fármacos
2.
Neuroimage ; 270: 119997, 2023 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-36868393

RESUMEN

The brain functions as an accurate circuit that regulates information to be sequentially propagated and processed in a hierarchical manner. However, it is still unknown how the brain is hierarchically organized and how information is dynamically propagated during high-level cognition. In this study, we developed a new scheme for quantifying the information transmission velocity (ITV) by combining electroencephalogram (EEG) and diffusion tensor imaging (DTI), and then mapped the cortical ITV network (ITVN) to explore the information transmission mechanism of the human brain. The application in MRI-EEG data of P300 revealed bottom-up and top-down ITVN interactions subserving P300 generation, which was comprised of four hierarchical modules. Among these four modules, information exchange between visual- and attention-activated regions occurred at a high velocity, related cognitive processes could thus be efficiently accomplished due to the heavy myelination of these regions. Moreover, inter-individual variability in P300 was probed to be attributed to the difference in information transmission efficiency of the brain, which may provide new insight into the cognitive degenerations in clinical neurodegenerative disorders, such as Alzheimer's disease, from the transmission velocity perspective. Together, these findings confirm the capacity of ITV to effectively determine the efficiency of information propagation in the brain.


Asunto(s)
Encéfalo , Imagen de Difusión Tensora , Humanos , Encéfalo/fisiología , Cognición/fisiología , Electroencefalografía/métodos , Mapeo Encefálico/métodos
3.
Ann Allergy Asthma Immunol ; 131(4): 466-473.e6, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37419414

RESUMEN

BACKGROUND: Childhood wheezing is a highly heterogeneous condition with an incomplete understanding of the characteristics of wheeze trajectories, particularly for persistent wheeze. OBJECTIVE: To characterize predictors and allergic comorbidities of distinct wheeze trajectories in a multiethnic Asian cohort. METHODS: A total of 974 mother-child pairs from the prospective Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort were included in this study. Wheeze and allergic comorbidities in the first 8 years of life were assessed using the modified International Study of Asthma and Allergies in Childhood questionnaires and skin prick tests. Group-based trajectory modeling was used to derive wheeze trajectories and regression was used to assess associations with predictive risk factors and allergic comorbidities. RESULTS: There were 4 wheeze trajectories derived, including the following: (1) early-onset with rapid remission from age 3 years (4.5%); (2) late-onset peaking at age 3 years and rapidly remitting from 4 years (8.1%); (3) persistent with a steady increase to age 5 years and high wheeze occurrence until 8 years (4.0%); and (4) no or low wheeze (83.4%). Early-onset wheezing was associated with respiratory infections during infancy and linked to subsequent nonallergic rhinitis throughout childhood. Late-onset and persistent wheeze shared similar origins characterized by parent-reported viral infections in later childhood. However, persistent wheezing was generally more strongly associated with a family history of allergy, parent-reported viral infections in later childhood, and allergic comorbidities as compared with late-onset wheezing. CONCLUSION: The timing of viral infection occurrence may determine the type of wheeze trajectory development in children. Children with a family history of allergy and viral infections in early life may be predisposed to persistent wheeze development and the associated comorbidities of early allergic sensitization and eczema.


Asunto(s)
Asma , Hipersensibilidad , Virosis , Humanos , Lactante , Preescolar , Estudios Prospectivos , Ruidos Respiratorios/etiología , Hipersensibilidad/epidemiología , Hipersensibilidad/complicaciones , Asma/complicaciones , Factores de Riesgo , Virosis/complicaciones
4.
Langenbecks Arch Surg ; 408(1): 317, 2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37587225

RESUMEN

BACKGROUND: Reducing clinically relevant post-operative pancreatic fistula (CR-POPF) incidence after pancreatic resections has been a topic of great academic interest. Optimizing post-operative drain management is a potential strategy in reducing this major complication. METHODS: Studies involving pancreatic resections, including both pancreaticoduodenectomy (PD) and distal pancreatic resections (DP), with intra-operative drain placement were screened. Early drain removal was defined as removal before or on the 3rd post-operative day (POD) while late drain removal was defined as after the 3rd POD. The primary outcome was CR-POPF, International Study Group of Pancreatic Surgery (ISGPS) Grade B and above. Secondary outcomes were all complications, severe complications, post-operative haemorrhage, intra-abdominal infections, delayed gastric emptying, reoperation, length of stay, readmission, and mortality. RESULTS: Nine studies met the inclusion criteria and were included for analysis. The studies had a total of 8574 patients, comprising 1946 in the early removal group and 6628 in the late removal group. Early drain removal was associated with a significantly lower risk of CR-POPF (OR: 0.24, p < 0.01). Significant reduction in risk of post-operative haemorrhage (OR: 0.55, p < 0.01), intra-abdominal infection (OR: 0.35, p < 0.01), re-admission (OR: 0.63, p < 0.01), re-operation (OR: 0.70, p = 0.03), presence of any complications (OR: 0.46, p < 0.01), and reduced length of stay (SMD: -0.75, p < 0.01) in the early removal group was also observed. CONCLUSION: Early drain removal is associated with significant reductions in incidence of CR-POPF and other post-operative complications. Further prospective randomised trials in this area are recommended to validate these findings.


Asunto(s)
Infecciones Intraabdominales , Pancreatectomía , Humanos , Pancreatectomía/efectos adversos , Remoción de Dispositivos , Páncreas , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Hemorragia Posoperatoria/epidemiología , Hemorragia Posoperatoria/etiología
5.
Eur Spine J ; 32(7): 2493-2502, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37191676

RESUMEN

PURPOSE: Allogeneic blood transfusion (ABT) is current standard of blood replenishment despite known complications. Salvaged blood transfusion (SBT) addresses majority of such complications. Surgeons remain reluctant to employ SBT in metastatic spine tumour surgery (MSTS), despite ample laboratory evidence. This prompted us to conduct a prospective clinical study to ascertain safety of intraoperative cell salvage (IOCS), in MSTS. METHODS: Our prospective study included 73 patients who underwent MSTS from 2014 to 2017. Demographics, tumour histology and burden, clinical findings, modified Tokuhashi score, operative and blood transfusion (BT) details were recorded. Patients were divided based on BT type: no blood transfusion (NBT) and SBT/ABT. Primary outcomes assessed were overall survival (OS), and tumour progression was evaluated using RECIST (v1.1) employing follow-up radiological investigations at 6, 12 and 24 months, classifying patients with non-progressive and progressive disease. RESULTS: Seventy-three patients [39:34(M/F)] had mean age of 61 years. Overall median follow-up and survival were 26 and 12 months, respectively. All three groups were comparable for demographics and tumour characteristics. Overall median blood loss was 500 mL, and BT was 1000 mL. Twenty-six (35.6%) patients received SBT, 27 (37.0%) ABT and 20 (27.4%) NBT. Females had lower OS and higher risk of tumour progression. SBT had better OS and reduced risk of tumour progression than ABT group. Total blood loss was not associated with tumour progression. Infective complications other than SSI were significantly (p = 0.027) higher in ABT than NBT/SBT groups. CONCLUSIONS: Patients of SBT had OS and tumour progression better than ABT/NBT groups. This is the first prospective study to report of SBT in comparison with control groups in MSTS.


Asunto(s)
Transfusión de Sangre Autóloga , Neoplasias de la Columna Vertebral , Femenino , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias de la Columna Vertebral/diagnóstico por imagen , Neoplasias de la Columna Vertebral/cirugía , Neoplasias de la Columna Vertebral/patología , Transfusión Sanguínea
6.
Ecotoxicol Environ Saf ; 264: 115442, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37672938

RESUMEN

Polyamines (PAs) are small aliphatic nitrogenous bases with strong biological activity that participate in plant stress response signaling and the alleviation of damage from stress. Herein, the effects of the PA-producing bacterium Bacillus megaterium N3 and PAs on the immobilization of Cd and inhibition of Cd absorption by spinach and the underlying mechanisms were studied. A solution test showed that strain N3 secreted spermine and spermidine in the presence of Cd. Both strain N3 and the PAs (spermine+spermidine) immobilized Cd and increased the pH of the solution. Untargeted metabolomics results showed that strain N3 secreted PAs, N1-acetylspermidine, 3-indolepropionic acid, indole-3-acetaldehyde, cysteinyl-gamma-glutamate, and choline, which correlated with plant growth promotion and Cd immobilization. A pot experiment showed that rhizosphere soil inoculation with strain N3 and PAs improved spinach dry weight and reduced spinach Cd absorption compared with the control. These positive effects were likely due to the increase in rhizosphere soil pH and NH4+-N and PA contents, which can be attributed primarily to Cd immobilization. Moreover, inoculation with strain N3 more effectively inhibited the absorption of Cd by spinach than spraying PAs, mainly because strain N3 enabled a better relative abundance of bacteria (Microvirga, Pedobacter, Bacillus, Brevundimonas, Pseudomonas, Serratia, Devosid, and Aminobacter), that have been reported to have the ability to resist heavy metals and produce PAs. Strain N3 regulated the structure of rhizosphere functional bacterial communities and inhibited Cd uptake by spinach. These results provide a theoretical basis for the prevention of heavy metal absorption by vegetables using PA-producing bacteria.


Asunto(s)
Bacillus megaterium , Poliaminas , Espermidina/farmacología , Espermina , Cadmio/toxicidad , Spinacia oleracea , Rizosfera
7.
Ecotoxicol Environ Saf ; 264: 115439, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37690172

RESUMEN

Microplastics (MPs) can act as carriers for environmental pollutants; therefore, MPs combined with heavy metal pollution are attracting increasing attention from researchers. In this study, the potential of the plant growth-promoting bacterium Bacillus sp. SL-413 to mitigate the stress caused by exposure to both MPs and cadmium (Cd) in sorghum plants was investigated. The effects of inoculation on sorghum biomass were investigated using hydroponic experiments, and evaluation of Cd accumulation and enzyme activity changes and transcriptomics approaches were used to analyze its effect on sorghum gene expression. The results showed that combined polyethylene (PE) and Cd pollution reduced the length and the fresh and dry weights of sorghum plants and thus exerted a synergistic toxic effect. However, inoculation with the strains alleviated the stress caused by the combined pollution and significantly increased the biomass. Inoculation increased the dry weights of the aboveground and belowground parts by 11.5-44.6% and 14.9-38.4%, respectively. Plant physiological measurements indicated that inoculation reduced the reactive oxygen species (ROS) content of sorghum by 10.5-27.2% and thereby alleviated oxidative stress. Transcriptome sequencing showed that exposure to combined Cd+MP contamination induced downregulation of gene expression, particularly that of genes related to amino sugar and nucleotide sugar metabolism, starch and sucrose metabolism, and plant hormone signal transduction, in sorghum. However, inoculation with Bacillus sp. SL-413 resulted in an increase in the proportion of upregulated genes involved in signal transduction, antioxidant defense, cell wall biology, and other metabolic pathways, which included the phenylpropanoid biosynthesis, photosynthesis, flavonoid biosynthesis, and MAPK signaling pathways. The upregulation of these genes promoted the tolerance of sorghum under combined Cd+MP pollution stress and alleviated the stress induced by these conditions. This study provides the first demonstration that plant growth-promoting bacteria can alleviate the stress caused by combined pollution with MPs and Cd by regulating plant gene expression. These findings provide a reference for the combined plant-microbial remediation of MPs and Cd.


Asunto(s)
Bacillus , Sorghum , Cadmio/toxicidad , Antioxidantes , Plásticos , Microplásticos , Sorghum/genética , Bacterias , Bacillus/genética , Peso Corporal , Expresión Génica
8.
J Gastroenterol Hepatol ; 37(6): 1043-1051, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35253271

RESUMEN

BACKGROUND AND AIM: A combination of platelet and elastography (PE criteria) was proposed to identify compensated advanced chronic liver disease (cACLD) patients at risk of liver decompensation. We aim to validate and refine PE criteria by developing a new predictive score to predict decompensation in Asian cACLD patients. METHODS: An international cohort of 633 cACLD patients with liver stiffness measurement (LSM) and esophagogastroduodenoscopy performed were included. We validated PE criteria to predict first liver decompensation using competing risk analysis, with death and hepatocellular carcinoma as competing events. We developed a predictive model using proportional subdistribution hazard regression. Prognostic accuracy was compared with the model of end-stage liver disease (MELD), albumin-bilirubin (ALBI), and ALBI-FIB-4 score using time-dependent area under operative characteristic curve (tAUC). RESULTS: Sixty patients developed decompensation over the median follow-up of 39 months. Favorable Baveno VI status ruled out cACLD patients at risk of liver decompensation. LSM > 25 kPa was suboptimal to predict cACLD patients who will develop liver decompensation. We developed CHESS-ALARM score by incorporating age, platelet, and gender into LSM. CHESS-ALARM score (tAUC = 0.86, 95% confidence interval [CI]: 0.79-0.94) has significantly higher accuracy than MELD (tAUC: 0.61), ALBI (tAUC: 0.62), ALBI-FIB-4 (tAUC: 0.70), and LSM > 25 kPa (tAUC: 0.54) to predict liver decompensation at 5 years (P < 0.05 for all). Patients with CHESS-ALARM score ≥ -0.37 had an 11-fold higher risk of decompensation (subdistribution hazard ratio = 11.2, 95% CI: 5.1-24.5). CONCLUSION: CHESS-ALARM score can be readily incorporated into clinical practice of cACLD patients to estimate individual risk of liver decompensation; however, more data are required in morbidly obese cACLD patients of nonviral etiology.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Enfermedad Hepática en Estado Terminal , Várices Esofágicas y Gástricas , Hepatopatías , Obesidad Mórbida , Várices Esofágicas y Gástricas/diagnóstico , Várices Esofágicas y Gástricas/etiología , Humanos , Cirrosis Hepática , Hepatopatías/complicaciones
9.
Curr Microbiol ; 79(12): 364, 2022 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-36253496

RESUMEN

Fusarium wilt caused by Fusarium oxysporum f. sp. niveum is an important manifestation of continuous cropping barrier, which causes the quality and yield of watermelon to decline. In early stage of this study, the organic fertilizer fermented by Bama pig manure applied in soil was proved to significantly inhibit the occurrence of disease by improving the structure of soil microbial community. However, the mechanism was not clear. The high-throughput sequencing technology, combined with network and PICRUSt2 function analysis was used to investigate it. MiSeq sequencing showed that the bacterial community of organic fertilizer treated soil was composed of 34 phyla and 768 genera, the number of genera was higher than that of sterile water treated soil. Fertilization significantly increased the diversity and changed the composition of bacterial community based on alpha, beta diversity, and ANOSIM/Adonis analysis. LEfSe species difference and network analysis showed that fertilization improved the relative abundance of bacteria with biological control or plant growth promotion characteristics in soil, such as Sphingomonas, Halobacillus, Nocardioides, and enhanced the interaction between rhizosphere bacteria, made the network structure more complex. PICRUSt2 also revealed fertilization promoted the bacterial function, such as metabolism and genetic information processing. These results showed that the pig manure organic fertilizer might reduce the occurrence of Fusarium wilt by regulating bacterial community, interaction, and functional metabolism in watermelon rhizosphere soil.


Asunto(s)
Citrullus , Fusarium , Animales , Bacterias , Citrullus/microbiología , Fertilizantes , Fusarium/fisiología , Estiércol , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Rizosfera , Suelo/química , Microbiología del Suelo , Porcinos , Agua
10.
Arch Microbiol ; 202(7): 1741-1748, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32328753

RESUMEN

A Gram-stain-negative, aerobic, and motile strain, TJ48T, was isolated from pakchoi-cultivated soil contaminated with Cd and Pb in Xinxiang (China). Cells of the strain were rod-shaped and colonies on LB agar were faint yellow. Strain TJ48T was positive for catalase and oxidase and the optimal condition for growth was 28 °C, with 1% (w/v) NaCl and at pH 7.0. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain TJ48T was closely related to the genus Rhodobacter and the closest relatives were Rhodobacter ovatus JA234T (97.4%, 16S rRNA gene sequence similarity) and Rhodobacter azotoformans KA25T (96.5%). The DNA G + C content of strain TJ48T was 64.7 mol%. Genome-to-genome distance calculations (GGDC) and ANIb values from genomic comparison between the genomes of strain TJ48T and the related reference species were less than 70% and 95%, respectively. The major cellular fatty acids were summed feature 8 (C18:1ω7c and/or C18:1ω6c) and C17:0. The only isoprenoid quinone detected was Ubiquinone-10 (Q-10). The polar lipid profile contains diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipids, and three unidentified lipids. Strain TJ48T significantly increased the dry weight of roots (26.2-66.3%) and shoots (16.7-37.8%) of pakchoi and reduced the Cd (50.2-60.1%) and Pb (55.6-60.9%) contents in pakchoi shoots and roots. On the basis of the physiological, genotypic and genomic characteristics, the strain TJ48T represent a novel species of the genus Rhodobacter, and the name Rhodobacter xinxiangensis sp. nov. is proposed (type strain TJ48T = CCTCC AB2019120T = KCTC 72510T).


Asunto(s)
Brassica/microbiología , Cadmio/metabolismo , Plomo/metabolismo , Filogenia , Rhodobacter/clasificación , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Brassica/metabolismo , China , ADN Bacteriano/genética , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Rhodobacter/genética , Análisis de Secuencia de ADN , Suelo/química , Contaminantes del Suelo
11.
Arch Microbiol ; 202(5): 1157-1171, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32067064

RESUMEN

Soil microbes play important roles in plant growth and in the biogeochemical cycling of earth's elements. However, the structure and functions of the microbial community associated with the growth of second-generation energy crops, such as Miscanthus, remain unclear. Thus, in this study, the composition and function of the bacterial and fungal communities associated with Miscanthus cultivation were analyzed by MiSeq sequencing combined with PICRUSt and FUNGUIld analyses. The results of community composition and diversity index analyses showed that Miscanthus cultivation significantly altered the bacterial and fungal community composition and reduced bacterial and fungal diversity. In addition, Miscanthus cultivation increased the soil organic matter (SOM) and total nitrogen (TN) contents. The correlation analysis between microbial community composition and environmental factors indicated that SOM and TN were the most important factors affecting bacterial and fungal communities. Miscanthus cultivation could enrich the abundances of Pseudomonas, Rhizobium, Luteibacter, Bradyrhizobium, Phenylobacterium and other common plant-promoting bacteria, while also increasing Cladophialophora, Hymenula, Magnaporthe, Mariannaea, etc., which predicted corresponded to the saprotrophic, plant pathogenic, and pathotrophic trophic modes. The PICRUSt predictive analysis indicated that Miscanthus cultivation altered the metabolic capabilities of bacterial communities, including the metabolism of carbon, nitrogen, and phosphorus cycle. In addition, FUNGUIld analysis indicated that Miscanthus cultivation altered the fungal trophic mode. The effects of Miscanthus on the communities and function of bacteria and fungi varied among Miscanthus species. Miscanthus specie Xiangdi NO 1 had the greatest impact on soil bacterial and fungal communities, whereas Miscanthus specie Wujiemang NO 1 had the greatest impact on soil bacteria and fungi functions. The results of this study provide a reference for the composition and function of microbial communities during the growth of Miscanthus.


Asunto(s)
Bacterias/genética , Hongos/genética , Microbiota/fisiología , Poaceae/crecimiento & desarrollo , Poaceae/microbiología , Rizosfera , Microbiología del Suelo , Agricultura , Secuenciación de Nucleótidos de Alto Rendimiento , Suelo/química
12.
Arch Microbiol ; 202(4): 859-873, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31894394

RESUMEN

Network analysis has contributed to studies of the interactions of microorganisms and the identification of key populations. However, such analysis has rarely been conducted in the study of reservoir bacterioplankton communities. This study investigated the bacterioplankton community composition in the surface water of the Danjiangkou Reservoir using the Illumina MiSeq sequencing platform. We observed that the bacterioplankton community primarily consisted of 27 phyla and 336 genera, including Actinobacteria, Proteobacteria, and Bacteroidetes, demonstrating the richness of the community composition. Redundancy analysis of the bacterioplankton communities and environmental variables showed that the total nitrogen (TN), pH, chemical oxygen demand (COD), and permanganate index (CODMn) were important factors affecting the bacterioplankton distribution. Network analysis was performed using the relative abundances of bacterioplankton based on the phylogenetic molecular ecological network (pMEN) method. The connectivity of node i within modules (Zi), the connectivity of node i among modules (Pi), and the number of key bacteria were high at the Taizishan and Heijizui sites, which were associated with higher TN contents than at the other sites. Among the physicochemical properties of water, TN, ammonia nitrogen (NH4-N), pH, COD, and dissolved oxygen (DO) might have great influences on the functional units of the bacterial communities in bacterioplankton molecular networks. This study improves the understanding of the structure and function of bacterioplankton communities in the Danjiangkou Reservoir.


Asunto(s)
Organismos Acuáticos/clasificación , Bacterias/clasificación , Bacterias/genética , Agua Dulce/microbiología , Plancton/clasificación , Plancton/genética , Biodiversidad , China , Demografía , Agua Dulce/química , Secuenciación de Nucleótidos de Alto Rendimiento , Filogenia , Plancton/microbiología
13.
Ecotoxicol Environ Saf ; 195: 110375, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32200142

RESUMEN

Microbial immobilization is a novel and environmentally friendly technology that uses microbes to reduce metal availability in soil and accumulation of heavy metals in plants. We used urea agar plates to isolate urease-producing bacteria from the rhizosphere soil of pakchoi in Cd- and Pb-contaminated farmland and investigated their effects on Cd and Pb accumulation in pakchoi and the underlying mechanisms. The results showed that two urease-producing bacteria, Bacillus megaterium N3 and Serratia liquefaciens H12, were identified by screening. They had higher ability to produce urease (57.5 ms cm-1 min-1 OD600-1 and 76.4 ms cm-1 min-1 OD600-1, respectively). The two strains allowed for the immobilization of Cd and Pb by extracellular adsorption, bioprecipitation, and increasing the pH (from 6.94 to 7.05-7.09), NH4+ content (69.1%-127%), and NH4+/NO3- ratio (from 1.37 to 1.67-2.11), thereby reducing the DTPA-extractable Cd (35.3%-58.8%) and Pb (37.8%-62.2%) contents in the pakchoi rhizosphere soils and the Cd (76.5%-79.7%) and Pb (76.3%-83.5%) contents in the leaves (edible tissue) of pakchoi. The strains were highly resistant to heavy metal toxicity; produced IAA, siderophores and abscisic acid; and increased the NH4+/NO3- ratio, which might be related to the two strains protectiing pakchoi against the toxic effect of Cd and Pb and increasing pakchoi biomass. Thus, the results were supposed to strain resources and a theoretical basis for the remediation of Cd- and Pb-contaminated farmlands for the safe production of vegetables.


Asunto(s)
Bacillus megaterium/aislamiento & purificación , Brassica/crecimiento & desarrollo , Cadmio/análisis , Plomo/análisis , Serratia liquefaciens/aislamiento & purificación , Microbiología del Suelo , Contaminantes del Suelo/análisis , Bacillus megaterium/metabolismo , Biodegradación Ambiental , Biomasa , Brassica/metabolismo , Cadmio/metabolismo , Granjas , Plomo/metabolismo , Rizosfera , Serratia liquefaciens/metabolismo , Suelo/química , Contaminantes del Suelo/metabolismo , Ureasa/metabolismo
14.
Plant Physiol ; 178(1): 428-440, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30030326

RESUMEN

The phytohormone abscisic acid (ABA) is critical for plants encountering abiotic stress. We reported previously that the Arabidopsis (Arabidopsis thaliana) transcription factor MYB30 participates in ABA responses via SUMO ligase SAP-MIZ Domain-Containing SIZ1-mediated sumoylation. Here, we show that the RING-type ubiquitin E3 ligase RHA2b, which positively regulates ABA signaling, interacted with and ubiquitinated MYB30 to modulate MYB30 stability through the 26S proteasome pathway. The degradation rate of MYB30 was repressed significantly in the rha2b-1 mutant. Phenotypic analyses showed that MYB30 acts genetically downstream of RHA2b in ABA signaling. Substitutions of lysine-283 (K283) and K165 blocked ubiquitination, suggesting that these residues are sites of ubiquitination. K283 residue substitution significantly inhibited the degradation of MYB30 induced by ABA. The K165 site functioned additively with K283 in ABA-induced MYB30 degradation and ABA responses. At the same time, sumoylation protected MYB30 from degradation under cycloheximide and ABA treatment. Compared with MYB30, overexpression of MYB30-SUMO1 partially recovered the ABA sensitivity of siz1-2 But MYB30-SUMO1 exhibited similar localization with MYB30 in nuclei. Overall, our results suggest that RHA2b targets MYB30 for degradation to modulate ABA signaling. Considering that the K283 residue also is the major site for sumoylation, we propose that sumoylation and ubiquitination act antagonistically in the ABA response to regulate the stability of MYB30 by occupying the same residue.


Asunto(s)
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ácido Abscísico/farmacología , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Mutación Missense , Reguladores del Crecimiento de las Plantas/metabolismo , Reguladores del Crecimiento de las Plantas/farmacología , Complejo de la Endopetidasa Proteasomal/metabolismo , Unión Proteica , Proteolisis , Sumoilación/efectos de los fármacos , Factores de Transcripción/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación/efectos de los fármacos
15.
Int J Syst Evol Microbiol ; 69(4): 1149-1154, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30767848

RESUMEN

A Gram-stain-negative, rod-shaped, motile bacterial strain, designated 3-5-3T, was isolated from maize-cultivated soil artificially contaminated with cadmium, in Nanyang, Henan Province, China. Strain 3-5-3T was oxidase- and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 3-5-3T was affiliated with the genus Paenibacillus and most closely related to Paenibacillus anaericanus MH2T (96.5 % similarity). The average nucleotide identity and digital DNA-DNA hybridization values between 3-5-3T and the closely related species ranged 69.4-84.5 % and 18.1-18.4 %. The genomic G+C content was 53.8 mol%. Anteiso-C15 : 0 was the major fatty acid and MK-7 was the only menaquinone. The diamino acid in the cell-wall peptidoglycan contains meso-diaminopimelic acid. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, two unidentified glycolipids, two unidentified aminolipids, one unidentified phospholipid, one unidentified phosphoaminolipid and six unidentified lipids. On the basis of the results obtained in this study, strain 3-5-3T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacilluszei soli sp. nov. is proposed. The type strain is 3-5-3T (=CGMCC 1.13686T=KCTC 33998T).


Asunto(s)
Cadmio , Paenibacillus/clasificación , Filogenia , Microbiología del Suelo , Contaminantes del Suelo , Zea mays , Técnicas de Tipificación Bacteriana , Composición de Base , Pared Celular/química , China , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Glucolípidos/química , Hibridación de Ácido Nucleico , Paenibacillus/aislamiento & purificación , Peptidoglicano/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
16.
Int J Syst Evol Microbiol ; 69(4): 1075-1080, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30747616

RESUMEN

A Gram-stain-positive, rod-shaped, motile bacterial strain, designated 3-2-2T, was isolated from field topsoil collected from a western suburb of Nanyang city, Henan province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 3-2-2T was a member of the genus Bacillus and most closely related to Bacillus fortis R-6514T (98.9 % similarity), Bacillus terrae RA9T (98.0 %) and Bacillus fordii R-7190T (97.7 %). A draft genome sequence determined for strain 3-2-2T revealed a DNA G+C content of 42.2 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between 3-2-2T and the closely related Bacillus species ranged 79.4-84.2 % and 23.4-24.6 %. The major fatty acids of strain 3-2-2T were iso-C15 : 0, anteiso-C15 : 0, iso-C14 : 0 and iso-C16 : 0. The major isoprenoid quinone was MK-7. meso-Diaminopimelic acid was detected in the peptidoglycan. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid and an unidentified lipid. The results of phylogenetic analyses, in silico genomic comparisons, and chemotaxonomic and phenotypic analyses clearly indicated that strain 3-2-2T represents a novel species within the genus Bacillus, for which the name Bacillus acidinfaciens sp. nov. is proposed. The type strain is 3-2-2T (=CGMCC 1.13685T=LMG 30839T).


Asunto(s)
Bacillus/clasificación , Granjas , Filogenia , Microbiología del Suelo , Bacillus/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Peptidoglicano/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
17.
Int J Syst Evol Microbiol ; 69(11): 3344-3349, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30540241

RESUMEN

In a survey of endophytic bacteria in Miscanthus sinensis, a strain of Gram-negative, non-endospore-forming, rod-shaped, aerobic bacterium was isolated and designated as RS10T. Phylogenetic analysis based on its 16S rRNA gene sequence showed that the strain RS10T was affiliated with the genus Pedobacter and exhibited the highest sequence similarities to Pedobacter kyungheensis KACC 16221T (97.78 %), Pedobacter roseus KCTC 22187T (97.75 %), Pedobacter humicola KACC 18452T (97.29 %) and Pedobacter soli KACC 14939T (97.23 %). The novel strain contained iso-C15 : 0, iso-C17 : 0-3OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as major fatty acids. The only isoprenoid quinone detected in strain RS10T was MK-7. Strain RS10T contains phosphatidylethanolamine and one kind of aminophospholipid as its major polar lipids. The DNA G+C content for RS10T was 39.8 mol%. Based on the results of phenotypic and genomic characterizations, we concluded that strains RS10T represents a novel species of Pedobacter, for which the name Pedobacter miscanthi sp. nov. is proposed. The type strain is RS10T (=KCTC 62786T=GDMCC 1.1415T).


Asunto(s)
Pedobacter/clasificación , Filogenia , Poaceae/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Pedobacter/aislamiento & purificación , Fosfolípidos/química , Tallos de la Planta/microbiología , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
18.
Antonie Van Leeuwenhoek ; 112(7): 1087-1094, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30707396

RESUMEN

In this study, a Gram-negative, rod-shaped, endophytic bacterial strain (RS1T) capable of producing large amounts of exopolysaccharides was isolated from a stem of Miscanthus sinensis. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RS1T is closely related to Mucilaginibacter kameinonensis NBRC 102645T (98.72%), followed by Mucilaginibacter gossypiicola Gh-48T (97.56%) and Mucilaginibacter oryzae DSM 19975T (97.36%). The DNA G + C content of strain RS1T was determined to be 42.80 mol%. ANIb and GGDC values from genomic comparison between the genomes of strain RS1T and the related reference species were less than 95% and 70%, respectively. The major cellular fatty acids (more than 10% of total fatty acids) were identified as iso-C15: 0, C16:0, iso-C17:0-3OH and summed feature 3 (C16: 1ω7c and/or iso-C15:02-OH). The only isoprenoid quinone detected was MK-7. Based on the physiological, genotypic and genomic characteristics, strain RS1T is concluded to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter endophyticus sp. nov. is proposed (type strain RS1T = KCTC 62785T = GDMCC 1.1414T).


Asunto(s)
Bacteroidetes/aislamiento & purificación , Endófitos/aislamiento & purificación , Poaceae/microbiología , Polisacáridos/metabolismo , Técnicas de Tipificación Bacteriana , Bacteroidetes/clasificación , Bacteroidetes/genética , Bacteroidetes/metabolismo , Composición de Base , ADN Bacteriano/genética , Endófitos/clasificación , Endófitos/genética , Endófitos/metabolismo , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Filogenia , Tallos de la Planta/microbiología , ARN Ribosómico 16S/genética
19.
HPB (Oxford) ; 20(4): 313-320, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29100711

RESUMEN

BACKGROUND: Single-staged laparoscopic common bile duct exploration (LCBDE) offers clear benefits in terms of cost and shorter hospitalization stays. However, a failed LCBDE requiring conversion to open surgery is associated with increased morbidity. This study reviewed the factors determining success of LCBDE, and created a predictive nomogram to stratify patients for the procedure. METHODS: A retrospective analysis of 109 patients who underwent LCBDE was performed. A nomogram was developed from factors significantly associated with conversion to open surgery and validated. RESULTS: Sixty-two patients underwent a successful LCBDE, while 47 patients required a conversion to open CBDE. The presence of underlying cholangitis (crude OR 2.70, 95% CI: 1.12-6.56, p = 0.017), together with its subsequent interventions, seemed to adversely increase the rate of conversion to open surgery. The predictive factors included in the nomogram for a failed laparoscopic CBDE included prior antibiotic use (adjusted OR (AOR) 2.98, 95% CI: 1.17-7.57, p = 0.022), previous ERCP (AOR 4.99, 95% CI: 2.02-12.36, p = 0.001) and abnormal biliary anatomy (AOR 9.37, 95% CI: 2.18-40.20, p = 0.003). CONCLUSION: LCBDE is useful for the treatment of choledocholithiasis. However, patients who were predicted to have an elevated risk for open conversion might not be ideal candidates for the procedure.


Asunto(s)
Colecistectomía Laparoscópica , Coledocolitiasis/cirugía , Técnicas de Apoyo para la Decisión , Nomogramas , Adulto , Anciano , Colecistectomía Laparoscópica/efectos adversos , Coledocolitiasis/diagnóstico por imagen , Toma de Decisiones Clínicas , Conducto Colédoco/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Selección de Paciente , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento
20.
Ecotoxicol Environ Saf ; 145: 111-118, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28711820

RESUMEN

Two energy crops (maize and soybean) were used in the remediation of cadmium-contaminated soils. These crops were used because they are fast growing, have a large biomass and are good sources for bioenergy production. The total accumulation of cadmium in maize and soybean plants was 393.01 and 263.24µg pot-1, respectively. The rhizosphere bacterial community composition was studied by MiSeq sequencing. Phylogenetic analysis was performed using 16S rRNA gene sequences. The rhizosphere bacteria were divided into 33 major phylogenetic groups according to phyla. The dominant phylogenetic groups included Proteobacteria, Acidobacteria, Actinobacteria, Gemmatimonadetes, and Bacteroidetes. Based on principal component analysis (PCA) and unweighted pair group with arithmetic mean (UPGMA) analysis, we found that the bacterial community was influenced by cadmium addition and bioenergy cropping. Three molecular ecological networks were constructed for the unplanted, soybean- and maize-planted bacterial communities grown in 50mgkg-1 cadmium-contaminated soils. The results indicated that bioenergy cropping increased the complexity of the bacterial community network as evidenced by a higher total number of nodes, the average geodesic distance (GD), the modularity and a shorter geodesic distance. Proteobacteria and Acidobacteria were the keystone bacteria connecting different co-expressed operational taxonomic units (OTUs). The results showed that bioenergy cropping altered the topological roles of individual OTUs and keystone populations. This is the first study to reveal the effects of bioenergy cropping on microbial interactions in the phytoremediation of cadmium-contaminated soils by network reconstruction. This method can greatly enhance our understanding of the mechanisms of plant-microbe-metal interactions in metal-polluted ecosystems.


Asunto(s)
Biocombustibles , Cadmio/análisis , Glycine max/crecimiento & desarrollo , Metagenómica , Consorcios Microbianos/genética , Contaminantes del Suelo/análisis , Zea mays/crecimiento & desarrollo , Biodegradación Ambiental , Cadmio/metabolismo , Filogenia , ARN Ribosómico 16S/genética , Rizosfera , Microbiología del Suelo/normas , Contaminantes del Suelo/metabolismo , Glycine max/metabolismo , Zea mays/metabolismo
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