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INTRODUCTION: Poststroke sleep disturbances are common and can affect stroke outcomes, but the clinical studies mainly focus on breathing-related sleep disorders, while the bidirectional impact of circadian rhythm dysfunction in ischemic stroke remains unknown. This study observed the characteristics of melatonin secretion in acute ischemic stroke patients and evaluated whether melatonin rhythm impacts the prognosis after stroke by assessing the neurological function, cognition, emotion, and quality of life 3 months after stroke. METHODS: Acute ischemic stroke patients were selected from the Department of Neurology Inpatients of the Second Hospital affiliated with Soochow University from October 2019 to July 2021. Healthy control subjects were recruited at the same time. Demographic and clinical data were collected, and relevant scale scores (including neurological function, cognition, emotion, and sleep) were assessed within 2 weeks of onset and followed up 3 months later. All participants collected salivary melatonin samples on the 4th day of hospitalization and dim light melatonin onset (DLMO) was calculated according to melatonin concentration. Stroke patients were then divided into three groups based on their DLMO values. RESULTS: A total of 74 stroke patients and 33 control subjects were included in this analysis. Compared with healthy controls, stroke patients exhibited a delayed melatonin rhythm during the acute phase of stroke (21:36 vs. 20:38, p = 0.004). Stroke patients were then divided into three groups, namely normal (n = 36), delayed (n = 28), or advanced DLMO (n = 10), based on their DLMO values. A χ2 test showed that there were significant differences in the rate of poor prognosis (p = 0.011) and depression tendency (p = 0.028) among the three groups. A further pairwise comparison revealed that stroke patients with delayed DLMO were more likely to experience poor short-term outcomes than normal DLMO group (p = 0.003). The average melatonin concentration of stroke patients at 5 time points was significantly lower than that of the control group (3.145 vs. 7.065 pg/mL, p < 0.001). Accordingly, we split stroke patients into three groups, namely low melatonin level (n = 14), normal melatonin level (n = 54), or high melatonin level (n = 6). Unfortunately, there were no great differences in the clinical characteristics, cognition, emotion, sleep quality, and short-term outcome among groups. CONCLUSIONS: This is a preliminary study, and our results indicate that changes in melatonin secretion phase of stroke patients may have effect on their short-term prognosis.
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AVC Isquêmico , Melatonina , Acidente Vascular Cerebral , Humanos , Melatonina/análise , Qualidade de Vida , Ritmo Circadiano , Sono , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , PrognósticoRESUMO
The CuS/RGO composites were prepared using a facile one-step solvothermal method. The asobtained samples were characterized by X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Brunner-Emmet-Teller (BET) measurements and UV-Vis spectrophotometry. The results showed that the CuS particles were uniformly dispersed on the surface of RGO and electronic migration effect existed between RGO and CuS. The photocatalytic activity of CuS/RGO composites was evaluated by the degradation of Cationic blue SD-BL, Cationic red X-5GN, Direct blue 86, Reactive blue KN-R, Methylene blue and Rhodamine B under visible light irradiation. The photocatalytic experiments showed that the CuS/RGO composites exhibited a better photocatalytic performance for organic dyes with absence of hydrogen peroxide (H2O2) due to the inhibition of recombination of electron-hole pair induced on the surface of CuS. The photodegradation ratio of Cationic blue SD-BL, Cationic red X-5GN, Direct blue 86, Reactive blue KN-R, Methylene blue and Rhodamine B increased to 100%, 95.8%, 99.5%, 87.8%, 100%, 81% after 75 min of irradiation, respectively. Moreover, no significant decline of CuS/RGO photocatalyst for photodegradation of dyes was observed after five cycles, indicating better photostability of the samples. Thus, the CuS/RGO composites could have a promising application in wastewater treatment.
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Molecular tests revealed influenza D viruses of D/OK lineage widely circulating in farmed animal species in Guangdong Province, southern China. In particular, we found high levels of influenza D virus infection in goats and pigs. We also detected viral RNA in serum specimens and feces of animals with certain severe diseases.
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Doenças dos Animais/epidemiologia , Doenças dos Animais/virologia , Infecções por Orthomyxoviridae/veterinária , Thogotovirus , Animais , China/epidemiologia , Geografia Médica , Humanos , Filogenia , ZoonosesRESUMO
Reticuloendotheliosis virus (REV), an important immunosuppressive pathogen, has many hosts, including chickens, ducks, geese, turkeys, and wild birds. Clinically, REV may lead to increased susceptibility to other pathogens, resulting in serious tissue damage (especially tumors) and the death of its host. In this study, we encountered a disease outbreak resulting in a large number of deaths of pigeons in Guangdong Province, Southern China. Histopathological analysis revealed apparent tumor-like lesions in multiple organs of pigeons. PCR assays for detection of tumor-associated pathogens (REV, avian leukosis virus, and Marek's disease virus) in poultry revealed the presence of REV sequences only. Moreover, fowlpox virus (FPV) with an insertion of REV long terminal repeat (LTR) sequences was also considered, but it was excluded using a specific PCR assay. To gain more genetic information, two full-length REV genome sequences were determined and found to have the highest nucleotide sequence similarity (99.9 %) and the closest genetic relationship to a vaccine strain (MD-2) and had a more distant genetic relationship (94.3 %) to a duck-origin strain (ATCC-VR775). To confirm the presence of REVs in pigeons, specific-pathogen-free (SPF) chickens and healthy pigeons were inoculated with microfiltered tumor tissue homogenates and were found to be susceptible to infection with REV. To our knowledge, this is the first report of REV in pigeons, and the data suggest that pigeons may be the natural host of REV.
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Doenças das Aves/virologia , Columbidae/virologia , Vírus da Reticuloendoteliose/isolamento & purificação , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/patologia , Galinhas , China/epidemiologia , Patos , Genoma Viral , Filogenia , Doenças das Aves Domésticas/virologia , Vírus da Reticuloendoteliose/classificação , Vírus da Reticuloendoteliose/genética , Vírus da Reticuloendoteliose/fisiologiaRESUMO
Porcine circovirus type 2 (PCV2) is considered the major etiological pathogen of porcine circovirus-associated diseases (PCVADs) in pigs. Recently, PCV2 was also found in non-porcine animals such as cattle, rats, and mice. However, there was no record of PCV2 in rats in China. The goal of this study was to investigate whether PCV2 was present in rats (Rattus norvegicus, RN) on three swine farms, using molecular tools. PCR results showed that 30 of 95 (31.6 %) rat samples were positive for PCV2. Moreover, further genotype analysis suggested that 10 of 30 (33.3 %) were positive for PCV2a, 19 of 30 (63.3 %) were positive for PCV2b, and only one sample (1/30, 3.33 %) was co-infected by PCV2a and PCV2b. To determine the possible origin of PCV2, 60 serum samples were also collected from weaned pigs on those swine farms, and 23 out of 60 samples were positive for PCV2. In addition, two distinct RN-origin and two distinct porcine-origin PCV2 full-length nucleotide sequences were obtained from the farms. Sequence and phylogenetic analysis indicated that they had the highest nucleotide similarity and closest genetic relationships to each other. In this study, we report the infection and genome characterization of PCV2 in rats and compare RN-origin and porcine-origin PCV2 sequences obtained from the same pig farm, revealing possible cross-species transmission of PCV2.
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Infecções por Circoviridae/veterinária , Circovirus/classificação , Circovirus/isolamento & purificação , Fazendas , Ratos/virologia , Animais , China , Infecções por Circoviridae/virologia , Circovirus/genética , Análise por Conglomerados , DNA Viral/química , DNA Viral/genética , Genoma Viral , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência , Suínos/virologiaRESUMO
Reservoir sediment is one of the most stressful environments for microorganisms due to periodically oxygen minimum conditions. In this study, the abundance and composition of bacteria associated with sediments from three drinking water reservoirs (Zhoucun, ZCR; Shibianyu, SBYR; and Jinpen, JPR) were investigated by quantitative polymerase chain reaction and 16S rRNA-based 454 pyrosequencing. The results of physico-chemical analysis of sediments showed that the organic matter and total nitrogen were significantly higher in ZCR as compared to JPR (P < 0.01). The bacterial abundance was 9.13 × 10(6), 1.14 × 10(7), and 6.35 × 10(6) copies/ng DNA in sediments of SBYR, ZCR, and JPR, respectively (P < 0.01). The pyrosequencing revealed a total of 9,673 operational taxonomic units, which were affiliated with 17 phyla. The dominant phylum was Firmicutes (56.83%) in JPR; whereas, the dominance of Proteobacteria was observed in SBYR with 40.38% and ZCR with 39.56%. The Shannon-Wiener diversity (H') was high in ZCR; whereas, Chao 1 richness was high in SBYR. The dominant genera were Clostridium with 42.15% and Bacillus with 20.44% in JPR. Meanwhile, Dechloromonas with 14.80% and Smithella with 7.20% were dominated in ZCR, and Bacillus with 45.45% and Acinetobacter with 5.15% in SBYR. The heat map profiles and redundancy analysis indicated substantial differences in sediment bacterial community composition among three reservoirs. Moreover, it appears from the results that physico-chemical variables of sediments including pH, organic matter, total nitrogen, and available phosphorous played key roles in shaping the bacterial community diversity. The results obtained from this study will broaden our understanding on the bacterial community structure of sediments in oxygen minimum and stressful freshwater environments.
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Bactérias/isolamento & purificação , Água Potável/microbiologia , Sedimentos Geológicos/microbiologia , Microbiota , Oxigênio/análise , China , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNARESUMO
Currently, porcine circovirus type 2 (PCV2) is considered the major pathogen of porcine circovirus associated-diseases (PCVAD) that causes large economic losses for the swine industry in the world annually, including China. Since the first report of PCV2 in 1998, it has been drawing tremendous attention for the government, farming enterprises, farmers, and veterinary practitioners. Chinese researchers have conducted a number of molecular epidemiological work on PCV2 by molecular approaches in the past several years, which has resulted in the identification of novel PCV2 genotypes and PCV2-like agents as well as the description of new prevalence patterns. Since late 2009, commercial PCV2 vaccines, including the subunit vaccines and inactivated vaccines, have already been used in Chinese swine farms. The aim of this review is to update the insights into the prevalence and control of PCV2 in China, which would contribute to understanding the epidemiology, control measures and design of novel vaccines for PCV2.
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Infecções por Circoviridae/veterinária , Circovirus/classificação , Circovirus/genética , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Animais , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Circovirus/isolamento & purificação , Genótipo , Epidemiologia Molecular , Prevalência , Suínos , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologiaRESUMO
For the worldwide pig industries, porcine circovirus type 2 (PCV2) is an economically important pathogen. At present, the prevalence of PCV2 is common in Chinese swine herds. However, there is little information on PCV2 prevalence in non-porcine animals in China, such as bovids. Therefore, the goal of this study is to obtain the firsthand prevalence data of PCV2 in bovids in China. Two hundred and eighty serum and muscle samples from dairy cows (n = 180), buffalo (n = 50), and yellow cattle (n = 50) were analyzed by PCR. The detection results show that PCV2 infections (16 %, 8/50) only exist in buffaloes. In addition, there are different PCV2 viral DNAs identified by differential PCR in the same buffalo sample. Nucleotide sequencing and phylogenetic analysis results based on partial ORF1 and ORF2 sequences suggest that PCV2 strains have genetic diversity in buffaloes and they are divided into three different genotypes (PCV2b, PCV2d, and PCV2e, respectively). Moreover, to our knowledge, the PCV2d and PCV2e genotypes have not been previously reported in bovids. Through this study, the firsthand data of PCV2 prevalence in bovids in China was documented.
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Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/virologia , Infecções por Circoviridae/veterinária , Circovirus/classificação , Circovirus/isolamento & purificação , Variação Genética , Animais , Bovinos , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Circovirus/genética , Análise por Conglomerados , DNA Viral/química , DNA Viral/genética , Genótipo , Dados de Sequência Molecular , Músculos/virologia , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência , Soro/virologiaRESUMO
AIMS: We evaluated endogenous melatonin levels in the acute phase of cerebral infarction and explored the impact of possible changes in melatonin levels on the prognosis of patients. METHODS: This study recruited acute ischemic stroke (AIS) patients from the Department of the Second Affiliated Hospital of Soochow University between December 2019 and June 2021, along with healthy control subjects. Salivary melatonin samples were collected from each participant between 7 pm and 10 pm, and fasting plasma was collected the following morning to measure the levels of inflammatory markers. The prognosis was assessed through follow-up three months after discharge. The relationship between melatonin levels and plasma inflammatory markers was assessed, followed by an analysis of the effect of melatonin levels on patient prognosis. RESULTS: The study enrolled a total of 160 participants, including 120 AIS patients aged 50 years or older (61.7% male) and 40 age-matched controls (55.0% male). The AIS group exhibited lower salivary melatonin levels at 19 (P = 0.002), 20 (P < 0.001), 21 (P < 0.001), and 22 (P < 0.001) o'clock, and the average melatonin level was also lower (P < 0.001). Logistic regression analysis models indicated an association between low melatonin levels and poor prognosis. Salivary melatonin levels demonstrated good predictive ability for the prognosis of AIS patients. CONCLUSION: Melatonin levels were lower in AIS patients compared to controls. In addition, lower melatonin levels were associated with a poorer prognosis among AIS patients.
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AVC Isquêmico , Melatonina , Saliva , Humanos , Melatonina/metabolismo , Melatonina/sangue , Masculino , Feminino , Pessoa de Meia-Idade , Prognóstico , AVC Isquêmico/sangue , AVC Isquêmico/metabolismo , AVC Isquêmico/diagnóstico , Idoso , Saliva/metabolismo , Saliva/química , Biomarcadores/sangue , Biomarcadores/metabolismoRESUMO
From May to July of 2023, one pig farm in Heyuan city, Guangdong Province of China, suffered severe piglet death and sow reproductive disorders. The common pig viruses and bacteria tested negative. To uncover the possible cause of the disease, a metagenomic analysis was performed in the pooled small intestine samples from three 8-day-old diseased piglets. The results showed that Getah virus (GETV), an RNA virus, might be the potential pathogen that affects pig health. Subsequently, GETV nucleotide was detected in all of the 15 samples collected from three diseased piglets using quantitative reverse transcription PCR, suggesting GETV as the main pathogen of the disease. A GETV strain, designated as GDHYLC23, was successfully isolated using the swine testicle cell line. Sequence analysis showed that the epidemic strain had a unique 32-nucleotide repeat insertion in the 3' noncoding region. Phylogenetic analysis showed that GDHYLC23 belonged to the pandemic group III. The identification of GETV with new variations implies the continuous evolution of the virus, which poses potential threats to the swine industry.IMPORTANCEPig farms are faced with emerging and re-emerging viruses that may cause substantial economic loss. The identification of potentially pathogenic viruses helps to prevent and control the spread of diseases. In this study, by using metagenomic analysis, we found that a neglected virus, GETV with a unique insertion in the genome, was the main pathogen in one pig farm that suffered severe piglet death and sow reproductive disorders. Although the potential impact of such an insertion on viral pathogenicity is unknown, the surveillance of the continuing evolution of GETV in pig farms cannot be ignored.
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Filogenia , Doenças dos Suínos , Animais , Suínos , Doenças dos Suínos/virologia , Doenças dos Suínos/epidemiologia , China/epidemiologia , Metagenômica , Alphavirus/genética , Alphavirus/isolamento & purificação , Alphavirus/classificação , Genoma Viral/genética , FazendasRESUMO
Purpose: To evaluate the value of dynamic monitoring of procalcitonin (PCT) as a biomarker for the early diagnosis of postoperative infections in patients undergoing cardiac surgery. Methods: In total, 252 patients who underwent cardiac surgery were retrospectively included. The postoperative patients' PCT level, change value (â³PCT), and clearance rate (â³PCTc) were compared between the infected and noninfected groups in adult and pediatric patients on postoperative days (PODs) 1, 3, and 5. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the diagnostic value. Results: Procalcitonin concentration decreased progressively in the noninfected group in adult and pediatric patients; PCT concentration continued to rise until it peaked on POD 3 in the infected group. In adult patients, the AUC of PCT for diagnosis of infection on PODs 1, 3, and 5 were 0.626, 0.817, and 0.806, with the optimal cut-off values of 7.35, 3.63, and 1.73 ng/ml, respectively. The diagnostic efficiency of â³PCT3 and â³PCT C3 was significantly better than â³PCT5 and â³PCT C5 , respectively. In pediatric patients, the AUC of PCT for diagnosis of infection on PODs 1, 3, and 5 were 0.677, 0.747, and 0.756, respectively, and the optimal cut-off values were 27.62, 26.15, and 10.20 ng/ml. Conclusion: This study showed that dynamic monitoring of PCT levels could be an effective clinical means to help to discover postoperative infection earlier. The PCT level and its change indicators on POD 3 in adult patients and the PCT level on POD 5 in children can indicate infection.
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Pigs are often co-infected by different viral strains from the same virus. Up to now, there are few reports about co-existence of different porcine circovirus type 2 (PCV2) strains in China. The aim of this study was to evaluate it in Chinese swine herds. 118 PCV2 positive DNAs isolated from diseased pigs identified by classic PCR were re-detected using a modified differential PCR assay. The results indicated that co-existence rates of PCV2 were 32.2% (38/118) in diseased pigs and 0% (0/41) in asymptomatic pigs. Four PCV2 complete genomes were cloned from two co-infected samples and their nucleotide (nt) identities were 95%-97.3%. The phylogenetic analysis showed that four PCV2 strains were divided into different genotypes, PCV2a, PCV2b, PCV2d and PCV2e, respectively. In addition, co-existence were not detected in 41 serum samples from healthy pigs but PCV2 single infection (31.7%, 13/41) existed. These data revealed that the co-existence of different strains of PCV2 might contribute to the development of more severe clinical symptoms for pigs. This is the first report confirming the co-existence of different PCV2 strains in Chinese swine herds. Meanwhile, this study could help us to understand new infection and prevalence forms of PCV2 clinically.
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Infecções por Circoviridae/veterinária , Circovirus/genética , DNA Viral/genética , Genoma Viral , Doenças dos Suínos/virologia , Sequência de Aminoácidos , Animais , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/genética , Infecções por Circoviridae/virologia , Circovirus/classificação , Circovirus/isolamento & purificação , Clonagem Molecular , Coinfecção , Impressões Digitais de DNA , DNA Viral/classificação , DNA Viral/isolamento & purificação , Genótipo , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/métodos , Homologia de Sequência do Ácido Nucleico , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/genéticaRESUMO
In the drinking water reservoir ecosystem, phytoplankton and bacteria play important roles in shaping freshwater health and function. In this work, the associated bacterial community functional diversity during degradation of phytoplankton was determined using the substrate utilization profiling (BIOLOG) technique, meanwhile, the composition and concentration of phytoplankton were examined using a microscope. The results indicated that Euglena decreased 58.33% from 0 to 38 d, while the smallest degradation of Bacillariophyta was 20.19%. Average well color development (AWCD590nm) increased during the static periods from 0 to 38 d; however, the AWCD590nm of 18 and 38 d had no significant difference (p ï¼ 0.05). The Simpson's index (D) was in accordance with Shannon's diversity (H) and species richness(S); it was measured to be18 > 38 > 5 > 0d. There were significant differences in the pattern and level of carbon sources used by the phytoplankton-associated bacteria. In addition, the principle component analyses (PCA) suggested that the first principle component (PC1) and the second principle component (PC2) explained 46.76% and 21.49% of the total variation for bacterial community, respectively. Redundancy analysis (RDA) revealed that cell abundance of phytoplankton was negatively correlated with the AWCD590nm, amino acids and other functional indexes. Therefore, the data suggest that there are differences in the phytoplankton-associated bacterial community functional diversity during different static stages of water samples collected from the drinking water reservoir.
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Bactérias , Água Potável , Fitoplâncton , Biodiversidade , China , Ecossistema , Fitoplâncton/metabolismo , Estações do Ano , Microbiologia da ÁguaRESUMO
Phytoplankton and bacteria are important components of the aquatic food web, and play a critical role in substance circulation and energy exchange in freshwater ecosystems. The succession of algae is closely related to the metabolism and structural succession of bacterial populations in the water column. Thus, in this study, the vertical succession characteristics of phytoplankton and bacteria community structure and their coupling with water quality were investigated during an algal bloom in the Lijiahe Reservoir using high-throughput DNA sequencing and Biolog technologies. The results showed that the Lijiahe Reservoir was in the thermal stratification stage in August, and the pH, dissolved oxygen, and NH4+-N of the water column gradually decreased with depth (P<0.001). Algal cell concentration and chlorophyll a exhibited a simultaneous trend (P<0.001), and the maximum values in the surface layer were 3363.33×104 cells·L-1 and 7.03 µg·L-1, respectively. The algal community structure was dominated by Microcystis at water depths of 0 m and 3 m, and at 6 m water depth, Cyclotella replaced Microcystis as the most dominant algae, with a relative abundance of 57.28%. Biolog analysis indicated that the outbreak of Microcystis had a significant impact on bacterial metabolic activity and its relative abundance, but the diversity of bacterial population metabolic activity varied less. A total of 1420 operational taxonomic units were found by high-throughput sequencing, belonging to 10 bacterial phyla. Of these, Actinobacteria and Proteobacteria dominated in all water layers, and their relative abundances were more than 50%. The relative abundance of Chlorobi and Planctomycetes varied significantly with water depth, reaching their maxima at a depth of 6 m with values of 10.29% and 6.78%, respectively, which were both negatively correlated with algal density (P<0.05). Firmicutes and Gemmatimonadetes were positively correlated with algal density (P<0.05). A heat map fingerprint showed that the vertical distribution of the bacterial community structure of the Lijiahe Reservoir varied significantly, and with the increase in water depth, the bacterial community was more uniformly distributed and tended to diversify. Redundancy analysis (RDA) showed that the vertical distribution of the bacterial and algal community structure was regulated by different water qualities, and the difference was significant. This study investigated the coupling mechanism of algal and bacterial communities during the algal bloom in the Lijiahe Reservoir, and the results provided a scientific basis for the investigation of the molecular microecological driving mechanism of water-source algal blooms.
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Clorofila A , Qualidade da Água , Ecossistema , Eutrofização , FitoplânctonRESUMO
An efficient aerobic denitrifying bacterium was isolated from the sediments of the Jin Pen Reservoir in Xi'an. The strain was identified by morphological features and 16S rDNA sequences as Pseudomonas stutzeri and named it KK99. The denitrification characteristics of the strain and the expression level of the functional genes narG, nirS, and nosZ in aerobic/anaerobic conditions were investigated. The results showed that the strain can carry out both anaerobic and aerobic denitrification and has a high efficiency of denitrification, which occurs under both aerobic and anaerobic conditions; after 24 h, the removal rates of total nitrogen (TN) were 85.08% and 89.05%, respectively. Under both the conditions, the expression levels of the functional genes nosZ and nirS are high. nosZ plays a vital role in denitrification in the aerobic pathway, nirS plays a vital role in denitrification in the anaerobic pathway, and narG expression is low under both the conditions. At the same time, simultaneous nitrification and denitrification (SND) capacity of the strain was observed when nitrate and ammonium salts were the nitrogen sources, with the total nitrogen removal rate being 76% within 24 h in aerobic conditions. The P. stutzeri KK99 strain can be used for controlling eutrophication of micro-polluted water, and the application of total nitrogen reduction engineering.
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Desnitrificação , Genes Bacterianos , Pseudomonas stutzeri/genética , Aerobiose , China , Sedimentos Geológicos/microbiologia , Nitrificação , Nitrogênio , Pseudomonas stutzeri/isolamento & purificação , Microbiologia da ÁguaRESUMO
Freshwater fungal community composition plays pivotal roles in sustaining the function and health of drinking water reservoir ecosystems. To investigate the vertical evaluative characteristics of an aquatic fungal community under conditions of stable thermal stratification, water samples were collected at 0.5, 10, 25, 40, 60 and 70 m depths of Jinpen Reservoir during thermal stratification. Fungal community composition was determined using a high-throughput DNA sequencing technique and combined with water quality parameters. The results showed that the epilimnion, metalimnion, and hypolimnion water layers were formed in Jinpen Reservoir. The temperature decreased steadily from the surface at 22.33â to the bottom with 7.21â (P<0.05). The dissolved oxygen (DO) concentration decreased significantly from the surface to the bottom (P<0.05). The conductivity and the concentration total phosphorus and iron increased significantly from the surface to the bottom (P<0.05). The high-throughput DNA sequencing revealed a total of 1247 operational taxonomic units (OTUs), which were affiliated with four phylum, 14 classes, and 39 genera, including Zygomycota, Basidiomycota, Ascomycota, and Chytridiomycota. The highest Shannon diversity and Chao 1 were 3.45 and 360 at 60 m, respectively. The Shannon diversity and Chao 1 were significantly higher in the hypolimnion than in the metalimnion (P<0.05). Rhodotorula (27.23%), Alternaria (24.28%),Cladosporium (22.98%), Alternaria (32.00%), Didymella (17.47%), and Cladosporium (28.17%) were the dominant species at 0.5 m, 10 m, 25 m, 40 m, 60 m, and 70 m, respectively. There are a number of unclassified fungi at different water depths. The heat map profile indicated significant differences in the vertical distribution of the fungal community composition in Jinpen Reservoir. A principle component analysis (PCA) indicated that water temperature, DO, TP, and conductivity had dramatic influences on the vertical distribution of the fungal community composition. The results provide new insights on the relationship between water quality and fungal community composition during reservoir thermal stratified periods.
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Água Potável/microbiologia , Fungos/classificação , Microbiologia da Água , Qualidade da Água , China , Ecossistema , Sequenciamento de Nucleotídeos em Larga Escala , TemperaturaRESUMO
The effect of aerobic denitrifying bacteria is a hot topic in the field of water environment bioremediation. Aerobic denitrifier communities, H-30, X-10, and C-30, enriched by intermittent aeration, screened with screening culture media, and treated by ultrasonic waves, could perform high denitrification performance at the higher dissolved oxygen concentration of (7.2±0.6) mg ·L-1. The total nitrogen (TN) removal rate of aerobic denitrifier communities, H-30, X-10, and C-30, reached 83.04%, 83.40%, and 82.68%, respectively. There is lower nitrite accumulation during the process of denitrification. Illumina high-throughput DNA sequencing revealed that aerobic denitrifier compositions were significantly different among the three communities. The predominant strains of aerobic denitrifier communities, H-30, X-10, and C-30, were Bacillus subtilis, Paracoccus pantotrophus, and Pseudomonas stutzeri, respectively. The proportion of P. stutzeri in aerobic denitrifier communities H-30 and X-10 was almost the same, while Pseudomonas xiamenensis was only detected in H-30. These three efficient aerobic denitrifier communities provide a bacterium source guarantee for polluted water bioremediation of lakes and reservoirs in cities.
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Bactérias/classificação , Desnitrificação , Sedimentos Geológicos/microbiologia , Lagos/microbiologia , Aerobiose , Nitritos/isolamento & purificação , Nitrogênio/isolamento & purificaçãoRESUMO
Six micro-polluted landscape water bodies were selected to explore the relationship between water quality and the nirS-Type denitrifier community structure and diversity with an Illumina high-throughput sequencing technique. The results of a physico-chemical analysis of the water bodies showed that the Fengqing Park (FQ) and Laodong Park (LD) water bodies were classified as inferior â ¤ water quality, the Qujiang Park (QJ), Mutasi Park (MTS), and Xinjiyuan Park (XJY) water bodies were classified as â ¤ water quality, and the Yongyang Park (YY) water quality was classified as â £. The TN values varied from 1.21 mg·L-1 to 6.50 mg·L-1, with the lowest value found in YY and the highest in FQ (P<0.05). TP was significantly higher in LD (0.10 mg·L-1) and significantly lower in QJ[0.02 mg·L-1 (P<0.05)]. The NH4+-N in LD was 4.44 times higher than that in QJ and FQ (P<0.01). Illumina high-throughput sequencing revealed that the denitrifier community composition was significantly different among the six water bodies, and Paracoccus sp., Pseudomonas sp., and Rubrivivax sp. were the dominant genus species. A principle component analysis (PCA) indicated that the nirS-Type denitrifier communities of XJY and MTS were mainly regulated by NH4+-N and the permanganate index, LD and FQ were significantly influenced by NO3--N, NO2--N, TN, TP, and DO, and YY was significantly influenced by pH value. Our results showed that nirS-Type denitrifier communities were regulated by different water quality indicators.