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1.
Chemosphere ; 258: 127392, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947654

RESUMO

Discharge of urban stormwater containing organic matter, heavy metals and sometime human feces, to the natural aquatic reservoirs without any treatment is not only an environmental problem. It can lead to prevalence of antibiotic resistant bacteria in stormwater systems and transmission of antibiotic resistance genes to the environment. We performed antibiotic resistome identification and virus detection in stormwater samples from Stockholm, using publicly available metagenomic sequencing MinION data. A MinION platform offers low-cost, precise environmental metagenomics analysis. 37 groups of antibiotic resistant bacteria (ARB), 11 resistance types with 26 resistance mechanisms - antibiotic resistance genes (ARGs) giving tolerance to the aminoglycoside, beta-lactams, fosmidomycin, MLS, multidrug and vancomycin were identified using ARGpore pipeline. The majority of the identified bacteria species were related to the natural environment such as soil and were not dangerous to human. Alarmingly, human pathogenic bacteria carrying resistance to antibiotics currently used against them (Bordetella resistant to macrolides and multidrug resistant Propionibacterium avidum) were also found in the samples. Most abundant viruses identified belonged to Caudovirales and Herpesvirales and they were not carrying ARGs. Unlike the virome, resistome and ARB were not unique for stormwater sampling points. This results underline the need for extensive monitoring of the microbial community structure in the urban stormwater systems to assess antimicrobial resistance spread.


Assuntos
Farmacorresistência Bacteriana/genética , Metagenoma , Bactérias/efeitos dos fármacos , Monitoramento Ambiental , Fezes/microbiologia , Genes Bacterianos/efeitos dos fármacos , Humanos , Macrolídeos , Metagenômica/métodos , Microbiota/efeitos dos fármacos , Águas Residuárias/microbiologia , beta-Lactamas
2.
Ecotoxicol Environ Saf ; 205: 111365, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32977286

RESUMO

Work in wastewater treatment plants (WWTPs) can be associated with respiratory symptoms and diarrhea. The aim of this study was to obtain knowledge about WWTP workers' exposure to airborne bacteria and endotoxin, and the inflammatory potential (TIP) of their exposure, and to evaluate the risk posed by the exposure by 1) calculating a hazard index and relating the exposure to suggested occupational exposure limits (OELs), 2) estimating the potential deposition of bacteria in the airways, 3) relating it to the risk group classification of bacteria by the European Union, and 4) estimating the TIP of the personal exposure. A cohort of 14 workers were followed over one year. Bioaerosols were collected using personal and stationary samplers in a grid chamber house and an aeration tank area. Airborne bacteria were identified using (MALDI-TOF MS), and TIP of exposure was measured using HL-60 cells. A significant effect of season, work task, and person was found on the personal exposure. A hazard index based on exposure levels indicates that the risk caused by inhalation is low. In relation to suggested OELs, 14% and 34% of the personal exposure were exceeded for endotoxin (≥50 EU/m3) and bacteria (≥500 CFU/m3). At least 70% of the airborne bacteria in the grid chamber house and the aeration tank area could potentially deposit in the lower respiratory tract. From the personal samples, three of 131 bacterial species, Enterobacter cloacae, Staphylococcus aureus, and Yersinia enterocolitica are classified within Risk Group 2. Seven additional bacteria from the stationary samples belong to Risk Group 2. The bacterial species composition was affected significantly by season (p = 0.014) and by sampling type/area (p = 0.001). The TIP of WWTP workers' exposure was higher than of a reference sample, and the highest TIP was measured in autumn. TIP of personal exposure correlated with bacterial exposure. Based on the geometric average exposures to endotoxin (9.2 EU/m3) and bacteria (299 CFU/m3) and based on the calculated hazard index, the risk associated with exposure is low. However, since 43 of 106 exposure levels exceed suggested OELs, the TIP of exposure was elevated and associated with bacterial exposure, and WWTP workers were exposed to pathogenic bacteria, a continued focus on preventive measures is important. The identification of bacteria to species level in personal samples was necessary in the risk assessment, and measurement of the microbial composition made the source tracking possible.


Assuntos
Poluentes Ocupacionais do Ar/análise , Exposição Ocupacional/análise , Instalações de Eliminação de Resíduos , Eliminação de Resíduos Líquidos , Microbiologia do Ar , Bactérias , Endotoxinas/análise , Monitoramento Ambiental/métodos , Humanos , Exposição por Inalação/análise , Exposição Ocupacional/estatística & dados numéricos , Estações do Ano , Águas Residuárias/microbiologia
3.
Ecotoxicol Environ Saf ; 205: 111377, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979805

RESUMO

Antibiotic resistance genes (ARGs) are emerging micro-pollutants that pose potential threats to environments and humans. Sewage sludge from wastewater is an important source for ARGs and current studies mainly focus on their existence in microbial genomes. However, little is known about which ARGs are expressed even though ARGs expression remains a better proxy for functional activity. In this study, the expressed ARGs in sewage sludge were characterized by high-throughput quantitative PCR (296 primer sets) combined with transcriptional analysis. A total of 202 ARG transcripts were detected and their abundances ranged from 3.1 × 109 to 1.2 × 1010 copies/g dry weight. The sum abundance of five most abundant ARG transcripts (qacEdelta1-02, sul2, qacEdelta1-01, aadA2-03, tetX) exhibited a linear correlation with the total abundance of ARG transcripts (R2 = 0.88, p < 10-4), suggesting that these genes could be regarded as indicators to quantitatively predict the total abundance of expressed ARGs. Dynamics of expressed ARGs were observed with lower abundances in summer and winter than those in other seasons (p < 0.05, Kruskal-Wallis test). Variation partitioning analysis indicated that the shift in bacterial community structures induced by changes in environmental attributes might be the main driver for the dynamics of expressed ARGs. Results of this study provided new insights into the ARGs in sewage sludge.


Assuntos
Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Esgotos/microbiologia , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Águas Residuárias/microbiologia
4.
Chemosphere ; 254: 126926, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957303

RESUMO

In less than a decade, bioelectrochemical systems/microbial fuel cell integrated constructed wetlands (electroactive wetlands) have gained a considerable amount of attention due to enhanced wastewater treatment and electricity generation. The enhancement in treatment has majorly emanated from the electron transfer or flow, particularly in anaerobic regions. However, the chemistry associated with electron transfer is complex to understand in electroactive wetlands. The electroactive wetlands accommodate diverse microbial community in which each microbe set their own potential to further participate in electron transfer. The conductive materials/electrodes in electroactive wetlands also contain some potential, due to which, several conflicts occur between microbes and electrode, and results in inadequate electron transfer or involvement of some other reaction mechanisms. Still, there is a considerable research gap in understanding of electron transfer between electrode-anode and cathode in electroactive wetlands. Additionally, the interaction of microbes with the electrodes and understanding of mass transfer is also essential to further understand the electron recovery. This review mainly deals with the electron transfer mechanism and its role in pollutant removal and electricity generation in electroactive wetlands.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Transporte de Elétrons , Águas Residuárias , Purificação da Água/métodos , Áreas Alagadas , Eletrodos , Microbiota , Águas Residuárias/análise , Águas Residuárias/microbiologia
5.
Ecotoxicol Environ Saf ; 204: 111118, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32795704

RESUMO

Many indicators are involved in monitoring water quality. For instance, the fecal indicator bacteria are extremely important to detect the water quality. For this purpose, to better predict the total coliforms at the outlet of a Multi-Soil-Layering (MSL) system designed to treat domestic wastewater in rural areas, a neural network model has been developed and compared with linear regression model. The data was collected from the raw and treated wastewater of a three MSL systems during a one-year period in rural village, in Al-Haouz Province, Morocco. Fifteen physicochemical and bacteriological variables have undergone feature selection to select the best ones for predicting the total coliforms concentration in the effluent of MSL system. Furthermore, 80% of the available dataset were used to train and optimize the neural model using repeated cross validation technique. The remaining part (20%) was used to test the developed model. The neural network indicated excellent results compared to the linear regression. The optimal model was a neural network with one hidden layer and 11 neurons, where the R2 was about 97%. The importance analysis of each predictor was established, and it was found that pH and total suspended solids had the greatest influence on the total coliforms removal.


Assuntos
Monitoramento Ambiental/métodos , Redes Neurais de Computação , Águas Residuárias/microbiologia , Microbiologia da Água , Bactérias , Marrocos , Solo , Qualidade da Água
6.
PLoS One ; 15(8): e0238386, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853235

RESUMO

Moving Bed Biofilm Reactors (MBBRs) can efficiently treat wastewater by incorporating suspended biocarriers that provide attachment surfaces for active microorganisms. The performance of MBBRs for wastewater treatment is, among other factors, contingent upon the characteristics of the surface area of the biocarriers. Thus, novel biocarrier topology designs can potentially increase MBBR performance in a significant manner. The goal of this work is to assess the performance of 3-D-printed biofilter media biocarriers with varying surface area designs for use in nitrifying MBBRs for wastewater treatment. Mathematical models, rendering, and 3D printing were used to design and fabricate gyroid-shaped biocarriers with a high degree of complexity at three different levels of specific surface area (SSA), generally providing greater specific surface areas than currently available commercial designs. The biocarriers were inoculated with a nitrifying bacteria community, and tested in a series of batch reactors for ammonia conversion to nitrate, in three different experimental configurations: constant fill ratio, constant total surface area, and constant biocarrier media count. Results showed that large and medium SSA gyroid biocarriers delivered the best ammonia conversion performance of all designs, and significantly better than that of a standard commercial design. The percentage of ammonia nitrogen conversion at 8 hours for the best performing biocarrier design was: 99.33% (large SSA gyroid, constant fill ratio), 94.74% (medium SSA gyroid, constant total surface area), and 92.73% (large SSA gyroid, constant biocarrier media count). Additionally, it is shown that the ammonia conversion performance was correlated to the specific surface area of the biocarrier, with the greatest rates of ammonia conversion (99.33%) and nitrate production (2.7 mg/L) for manufactured gyroid biocarriers with a specific surface area greater than 1980.5 m2/m3. The results suggest that the performance of commercial MBBRs for wastewater treatment can be greatly improved by manipulation of media design through topology optimization.


Assuntos
Biofilmes/crescimento & desenvolvimento , Reatores Biológicos/microbiologia , Águas Residuárias/análise , Águas Residuárias/microbiologia , Amônia/química , Bactérias/crescimento & desenvolvimento , Meios de Comunicação de Massa , Nitratos/química , Nitrificação/fisiologia , Nitrogênio/química , Impressão Tridimensional , Eliminação de Resíduos Líquidos/métodos
7.
Parasitol Res ; 119(9): 3033-3040, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32748039

RESUMO

We assessed the potential contribution of hospitals to contaminations of wastewater by enteric protists, including Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in raw wastewater. Wastewater samples were collected from storage tanks in two hospitals and one associated wastewater treatment plant in Shanghai, China, from March to November 2009. Enteric pathogens were detected and identified using PCR and DNA sequencing techniques. Among a total of 164 samples analyzed, 31 (18.9%), 45 (27.4%), and 122 (74.4%) were positive for Cryptosporidium spp., G. duodenalis, and E. bieneusi, respectively. Altogether, three Cryptosporidium species, four G. duodenalis assemblages, and 12 E. bieneusi genotypes were detected. Cryptosporidium hominis, G. duodenalis sub-assemblage AII, and E. bieneusi genotype D were the dominant ones in wastewater from both hospitals and the wastewater treatment plant. A similar distribution in genotypes of enteric pathogens was seen between samples from hospitals and the wastewater treatment plant, suggesting that humans are one of the major sources for these pathogens and hospitals are important contributors of enteric parasites in urban wastewater. Data from this study might be useful in the formulation of preventive measures against environmental contamination of waterborne pathogens.


Assuntos
Infecção Hospitalar/microbiologia , Infecção Hospitalar/parasitologia , Cryptosporidium/isolamento & purificação , Enterocytozoon/isolamento & purificação , Giardia lamblia/isolamento & purificação , Águas Residuárias/microbiologia , Águas Residuárias/parasitologia , China/epidemiologia , Infecção Hospitalar/epidemiologia , Criptosporidiose/epidemiologia , Criptosporidiose/parasitologia , Cryptosporidium/classificação , Cryptosporidium/genética , Enterocytozoon/classificação , Enterocytozoon/genética , Genótipo , Giardia lamblia/classificação , Giardia lamblia/genética , Giardíase/epidemiologia , Giardíase/parasitologia , Hospitais , Humanos , Microsporidiose/epidemiologia , Microsporidiose/microbiologia , Reação em Cadeia da Polimerase
8.
Ecotoxicol Environ Saf ; 204: 111073, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32755736

RESUMO

The high pH and salinity of textile wastewater is a major hindrance to azo dye decolorization. In this study, a mixed bacterial consortium ZW1 was enriched under saline (10% salinity) and alkaline (pH 10.0) conditions to decolorize Methanil Yellow G (MY-G). Consortium ZW1 was mainly composed of Halomonas (49.8%), Marinobacter (30.7%) and Clostridiisalibacter (19.2%). The effects of physicochemical factors were systematically investigated, along with the degradation pathway and metagenome analysis. The co-carbon source was found to be necessary, and the addition of yeast extract led to 93.3% decolorization of 100 mg/L MY-G within 16 h (compared with 1.12% for control). The optimum pH, salinity, temperature and initial dye concentration were 8.0, 5-10%, 40 °C and 100 mg/L, respectively. The typical dye-related degradation enzymes were most effective at 10% salinity. Consortium ZW1 was also able to differentially decolorize five other direct and acidic dyes in a short period. Phototoxicity tests revealed the detoxification of MY-G degradation products. Combining UV-vis, FTIR and GC-MS detection, the MY-G degradation pathway by consortium ZW1 was proposed. Furthermore, metagenomic approach was used to elucidate the functional potential of genes in MY-G biodegradation. These results signify the broad potential application of halo-alkaliphilic consortia in the bioremediation of dyeing wastewater.


Assuntos
Compostos Azo/toxicidade , Corantes/toxicidade , Metagenoma , Microbiota/efeitos dos fármacos , Águas Residuárias , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos , Compostos Azo/metabolismo , Biodegradação Ambiental , Carbono/metabolismo , Corantes/metabolismo , Microbiota/genética , Salinidade , Temperatura , Indústria Têxtil , Águas Residuárias/química , Águas Residuárias/microbiologia , Poluentes Químicos da Água/metabolismo
9.
Artigo em Inglês | MEDLINE | ID: mdl-32728874

RESUMO

Pharmaceutical compounds end up in wastewater treatment plants but little is known on their effect towards the different microbial groups in anaerobic communities. In this work, the effect of the antibiotic Ciprofloxacin (CIP), the non-steroidal anti-inflammatory drugs Diclofenac (DCF) and Ibuprofen (IBP), and the hormone 17α-ethinylestradiol (EE2), on the activity of acetogens and methanogens in anaerobic communities, was investigated. Microbial communities were more affected by CIP, followed by EE2, DCF and IBP, but the response of the different microbial groups was dissimilar. For concentrations of 0.01 to 0.1 mg/L, the specific methanogenic activity was not affected. Acetogenic bacteria were sensitive to CIP concentrations above 1 mg/L, while DCF and EE2 toxicity was only detected for concentrations higher than 10 mg/L, and IBP had no effect in all concentrations tested. Acetoclastic methanogens showed higher sensitivity to the presence of these micropollutants, being affect by all the tested pharmaceutical compounds although at different degrees. Hydrogenotrophic methanogens were not affected by any concentration, indicating their lower sensitivity to these compounds when compared to acetoclasts and acetogens.


Assuntos
Bactérias/metabolismo , Poluentes Químicos da Água/efeitos adversos , Anaerobiose , Bactérias/efeitos dos fármacos , Ciprofloxacino/efeitos adversos , Diclofenaco/efeitos adversos , Etinilestradiol/efeitos adversos , Ibuprofeno/efeitos adversos , Microbiota/efeitos dos fármacos , Águas Residuárias/microbiologia
10.
Arch Microbiol ; 202(10): 2655-2661, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32715322

RESUMO

A Gram stain-negative, aerobic, non-motile, short, rod-shaped bacterial strain CAU 1482T was isolated from coal mine wastewater in Hongcheon, Korea. It grew well at 30 °C, pH 8.5, 2% NaCl (w/v). 16S rRNA-based phylogeny indicated that CAU 1482T forms a distinct lineage within Aureimonas with high similarity to Aureimonas frigidaquae CW5T (98.2%), Aureimonas altamirensis S21BT (98.0%), and Aureimonas glaciei B5-2T (96.3%). The predominant cellular fatty acids were C18:1 2-OH, C16:0, C18:1 ω7c, and/or C18:1 ω6c (summed feature 8), with Q-10 as the major isoprenoid quinone. The polar lipid profile comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified aminolipids, and three unidentified lipids. The 3.9-Mb genome included 8 contigs and 3599 protein-coding genes with a 56.7 mol% G + C content. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain CAU 1482T and closely related strains of A. frigidaquae CW5T and A. altamirensis S21BT were 72.2‒72.4% and 18.7‒18.8%, respectively. These phenotypic, chemotaxonomic, and phylogenetic data support CAU 1482T as a novel Aureimonas species, for which the name Aureimonas fodinaquatilis sp. nov. is proposed. The type strain is CAU 1482T (= KCTC 62995T = NBRC 113692T).


Assuntos
Alphaproteobacteria/classificação , Filogenia , Águas Residuárias/microbiologia , Alphaproteobacteria/genética , Alphaproteobacteria/isolamento & purificação , Composição de Bases , Carvão Mineral , Ácidos Graxos/análise , Genoma Bacteriano/genética , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Especificidade da Espécie
11.
Arch Microbiol ; 202(9): 2543-2550, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32656678

RESUMO

The present study aims to examine the in vitro antifungal susceptibility patterns of Candida species isolated from hospital wastewater, and the efficacy of widely used disinfectants (sodium hypochlorite and benzalkonium chloride) against planktonic and biofilm cells were assessed. Susceptibility testing demonstrated that the two azoles were more effective against C. albicans than non-albicans isolates. When we determine the efficiency of disinfectants against the planktonic cells, benzalkonium chloride did not show any activity in all the studied strains under tested conditions except C. albicans-1. However, sodium hypochlorite showed ≥ 4 log10 killing in viable cells for different contact times. On the other hand, while 0.1% and 1% concentrations of benzalkonium chloride showed fungicidal activity against biofilm cells, sodium hypochlorite at 1% only demonstrated fungicidal activity. Those results showed that surface water is a possible transmission path for fungi in the investigated hospital region and may be a health risk, especially for the immunocompromised host.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Desinfetantes/farmacologia , Águas Residuárias/microbiologia , Biofilmes/efeitos dos fármacos , Candida/isolamento & purificação , Testes de Sensibilidade Microbiana
12.
Ecotoxicol Environ Saf ; 203: 110945, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32684517

RESUMO

The high-concentration wastewater produced in the industrial reverse osmosis (RO) process contains a large amount of refractory organic matters, which will have serious impacts on the natural environment and human health. Among them, contaminants can be transformed by humus-reducing bacteria based on humus. In this study, O3- assisted UV-Fenton method was applied as pretreatment. Biological activated carbon (BAC) technology in which humus-reducing bacteria were the dominant bacteria, enhanced by electron donor and Fe3+, was used to dispose of RO concentrate (ROC). The results showed that water treatment process combining oxidation with biological filtration had a positive effect on the removal of stubborn contaminants in ROC. The system was strengthened by adding electron donor and Fe3+, and the chemical oxygen demand (COD) removal efficiency was up to 80.1%. However, when the removal efficiency of UV254 absorbing pollutants reached optimal value (87.3%), that means only Fe3+ was added.


Assuntos
Carvão Vegetal/análise , Compostos Férricos/química , Substâncias Húmicas , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Filtração/métodos , Substâncias Húmicas/análise , Substâncias Húmicas/microbiologia , Hidrocarbonetos Halogenados/análise , Peróxido de Hidrogênio/química , Ferro/química , Osmose , Oxirredução , Ozônio/química , Raios Ultravioleta , Águas Residuárias/análise , Águas Residuárias/microbiologia
13.
Chemosphere ; 258: 127326, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32535452

RESUMO

A novel combined dual microbial fuel cell (MFC) system was developed for the continuous removal of Victoria Blue R (VBR) and electricity generation. Anaerobic and aerobic VBR-degrading bacteria, Shewanella putrefaciens and Acinetobacter calcoaceticus, respectively, were applied simultaneously. The effects of various factors on the performance of the novel system in the continuous mode were investigated, and optimal operating parameters for the system were determined. The optimal liquid retention time for continuous treatment was 36 h. The optimal external resistances of connected MFCs were 390 Ω and 1300 Ω. When artificial wastewater containing 1000 mg/l of VBR was fed continuously into the system, the VBR removal efficiency achieved was 98.7%. In addition, the acute toxicity of the effluent was decreased by a factor of 21.1-22.3, indicating that the system could detoxify VBR intermediates. VBR degradation involved a stepwise demethylation process, which occurred mainly in the first MFC, whereas aromatic ring opening, sequential deamination reaction, and carbon oxidation occurred mainly in the second MFC. When actual VBR-containing wastewater (75-262 mg/l) was introduced, the removal efficiencies of VBR, chemical oxygen demand, colority, NH3, and bioelectricity generation were >99.8%, >96.6%, >88.0%, 100%, and >194.8 mW/m2, respectively and the original inoculated strains remained dominant. Therefore, the combined dual MFC system could be applied to the treatment of actual VBR-containing wastewater.


Assuntos
Corantes de Rosanilina/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Acinetobacter calcoaceticus/metabolismo , Fontes de Energia Bioelétrica/microbiologia , Análise da Demanda Biológica de Oxigênio , Eletricidade , Eletrodos , Shewanella putrefaciens/metabolismo , Têxteis , Águas Residuárias/microbiologia , Poluentes Químicos da Água/análise
14.
Protist ; 171(3): 125738, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32544845

RESUMO

This paper represents a comprehensive study of two new thraustochytrids and a marine Rhodotorula red yeast isolated from Australian coastal waters for their abilities to be a potential renewable feedstock for the nutraceutical, food, fishery and bioenergy industries. Mixotrophic growth of these species was assessed in the presence of different carbon sources: glycerol, glucose, fructose, galactose, xylose, and sucrose, starch, cellulose, malt extract, and potato peels. Up to 14g DW/L (4.6gDW/L-day and 2.8gDW/L-day) of biomass were produced by Aurantiochytrium and Thraustochytrium species, respectively. Thraustochytrids biomass contained up to 33% DW of lipids, rich in omega-3 polyunsaturated docosahexaenoic acid (C22:6, 124mg/g DW); up to 10.2mg/gDW of squalene and up to 61µg/gDW of total carotenoids, composed of astaxanthin, canthaxanthin, echinenone, and ß-carotene. Along with the accumulation of these added-value chemicals in biomass, thraustochytrid representatives showed the ability to secrete extracellular polysaccharide matrixes containing lipids and proteins. Rhodotorula sp lipids (26% DW) were enriched in palmitic acid (C16:0, 18mg/gDW) and oleic acid (C18:1, 41mg/gDW). Carotenoids (87µg/gDW) were mainly represented by ß-carotene (up to 54µg/gDW). Efficient growth on organic and inorganic sources of carbon and nitrogen from natural and anthropogenic wastewater pollutants along with intracellular and extracellular production of valuable nutrients makes the production of valuable chemicals from isolated species economical and sustainable.


Assuntos
Biodegradação Ambiental , Quitridiomicetos , Lipídeos/biossíntese , Rhodotorula , Poluentes da Água/metabolismo , Aciltransferases/metabolismo , Biomassa , Carotenoides/metabolismo , Quitridiomicetos/crescimento & desenvolvimento , Quitridiomicetos/isolamento & purificação , Quitridiomicetos/metabolismo , Ácidos Docosa-Hexaenoicos/biossíntese , Ácidos Graxos Insaturados/biossíntese , Nutrientes/metabolismo , Polissacarídeos/biossíntese , Rhodotorula/crescimento & desenvolvimento , Rhodotorula/isolamento & purificação , Rhodotorula/metabolismo , Água do Mar/microbiologia , Águas Residuárias/microbiologia , Áreas Alagadas
15.
Ecotoxicol Environ Saf ; 201: 110752, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32474208

RESUMO

Plant is an important part of constructed wetland (CW), while, its potential effect on nitrogen cycling is complicated. Herein, integrated vertical-flow constructed wetland (IVCW) in pilot-scale planted with Arundo donax (Planted System, PS) was constructed to treat swine wastewater. The removal performance of nitrogen in PS, effects of plant on the microbial community structure and nitrogen related function genes were revealed. Results showed that, Arundo donax planting enhanced the removal rate of TN, compared to unplanted IVCWs, the absolute abundance of Pseudomonas, Acinetobacter and Bacillus in PS was significantly increased, as well as the absolute abundance of functional gene (amoA, nxrA, nirK, nirS and nosZ). The denitrification process was mainly occurred in down-flow cell of PS with significantly higher abundant of nirK and nosZ (P < 0.05). These findings suggested that Arundo donax planting in IVCWs with zeolite as substrate promoted the growth of denitrifying microorganisms under higher pollutant load. In addition, the increased abundant of nosZ and the ratio of nosZ/∑nir indicating a lower genetic potential for N2O release. Our research provides new insight into the potential application of plant on the purification of swine wastewater.


Assuntos
Desnitrificação , Poaceae/metabolismo , Águas Residuárias/química , Purificação da Água/métodos , Áreas Alagadas , Animais , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Desnitrificação/genética , Nitrogênio/análise , Nitrogênio/isolamento & purificação , Nitrogênio/metabolismo , Suínos , Águas Residuárias/microbiologia , Zeolitas/metabolismo
16.
Ecotoxicol Environ Saf ; 201: 110739, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32505047

RESUMO

In the study, antibiotic resistance genes (ARGs) were examined in wastewater and sludge samples to explore the effect of cephalexin (CFX) on the spreading and removal of ARGs in the Expanded Granular Sludge Bed (EGSB) reactor treating antibiotics wastewater. The result showed that the addition of CFX in the wastewater affected the removal amount of ß-lactam ARGs and other types ARGs. Besides, the addition of CFX in the wastewater had no obviously effect on total concentration of targeted ARGs in the sludge, but it was related to the accumulation of some typical ARGs. Based on gene cassette array libraries analysis, the diversity of gene cassettes carried by intI1 gene was increased by the addition of CFX in the wastewater. Furthermore, the co-occurrence patterns between ARGs and bacterial genus were also investigated. The results showed the CFX in the wastewater not only affected the number of potential host bacteria of ARGs, but also changed the types of potential host bacteria of ARGs. The correlation analysis of ARG in influent, effluent and sludge showed that, for blaCTX-M, sul2, qnrS and AmpC genes, their removal amount in EGSB reactor treating antibiotic wastewater system might be enhanced by reducing their concentration in the sludge.


Assuntos
Antibacterianos/farmacologia , Cefalexina/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Antibacterianos/análise , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Cefalexina/análise , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/efeitos dos fármacos , Esgotos/química , Esgotos/microbiologia , Águas Residuárias/química
17.
Arch Microbiol ; 202(8): 2135-2145, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32519019

RESUMO

In Pakistan, 55% of textile exports are contributed by textile-units of Faisalabad. The effluents of these textile units, being discharged without any treatment, contain the contamination of a huge amount of synthetic azo dyes. The objective of the current research was to evaluate the contribution of an azoreductase-encoding gene (azrS) from a pre-characterized azo dye decolorizing bacterial strain Bacillus sp. MR-1/2 in a high copy number host system (pUC19-T7-Top-T) of Escherichia coli strain DH5α followed by in-silico prediction of azoreductase enzyme (AzrS) function. The recombinant cells that contained azrS had a significantly higher rate of color removal in congo red and reactive black-5 dyes when compared to wild-type MR-1/2 and E. coli DH5α after 72 h of incubation. Moreover, we were able to show that the recombinant strain significantly reduced the values of all tested parameters (pH, EC, turbidity, TSS, and COD) in actual wastewater. In support of our results, it was also predicted through bioinformatics analysis that the deduced azoreductase protein of strain MR-1/2 is linked with the dye decolorization ability of the strain through NAD(P)H-ubiquinone: oxidoreductase activity. Furthermore, we also found that the deduced protein resembled closely related proteins of protein databank in many features, yet some unique features were predicted in the enzyme activity of strain MR-1/2. It was concluded that the recombinant strain could be examined in pilot-scale experiments for textile wastewater treatment.


Assuntos
Compostos Azo/metabolismo , Bacillus/enzimologia , Bacillus/genética , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , Águas Residuárias/microbiologia , Purificação da Água , Compostos Azo/química , Biodegradação Ambiental , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/genética , Paquistão
18.
Chemosphere ; 258: 127271, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32535444

RESUMO

Water and soil contamination by industrial wastes is a global concern. Biological treatment of industrial wastewater using bioreactors allows the removal of organic matter and nutrients and enables either reuse or safe discharge. Wastewater bioremediation depends in part on the microbial communities present in the bioreactor. To ascertain which communities may play a role in the remediation process, the present study investigates the microbial community structure and diversity of microorganisms found in a full-scale membrane bioreactor (MBR) for industrial wastewater treatment. The study was carried out using high-throughput data observations following a failure (crash) of the MBR and during the extended recovery of the process. Results revealed a positive correlation between the MBR's ability to remove organic matter and its microbial community richness. The significant changes in relative microbial abundance between crash and recovery periods of the MBR revealed the important role of specific bacterial genera in wastewater treatment processes. A whole-genome metagenomics based comparison showed a clear difference in microbial makeup between two functional periods of MBR activity. The crash period was characterized by abundance in bacteria belonging to Achromobacter, Acinetobacter, Halomonas, Pseudomonas and an uncultured MBAE14. The recovery period on the other hand was characterized by Aquamicrobium and by Wenzhouxiangella marina. Our study also revealed some interesting functional pathways characterizing the microbial communities from the two periods of bioreactor function, such as Nitrate and Sulfate reduction pathways. These differences indicate the connection between the bacterial diversity of the MBR and its efficiency to remove TOC.


Assuntos
Reatores Biológicos/microbiologia , Microbiota/efeitos dos fármacos , Águas Residuárias , Purificação da Água/métodos , Biodegradação Ambiental , Gammaproteobacteria/efeitos dos fármacos , Gammaproteobacteria/genética , Resíduos Industriais/análise , Membranas Artificiais , Metagenômica , Microbiota/genética , Esgotos/microbiologia , Águas Residuárias/química , Águas Residuárias/microbiologia
19.
Chemosphere ; 258: 127281, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32540545

RESUMO

Development of Alberta's oil sands requires large volumes of water, leading to the abundance of oil sands process affected water (OSPW) that must be remediated prior to discharge or reuse. OSPW contains a variety of dissolved organic compounds, however naphthenic acids (NAs) have been found to contribute significantly to the toxicity of OSPW. A fungus, Trichoderma harzianum, isolated directly from OSPW, has previously demonstrated a high tolerance and capacity for growth in the presence of commercial NAs. This study conducted microcosm experiments to elucidate and characterize the capacity of T. harzianum to degrade labile commercial NAs (Merichem), and OSPW-sourced naphthenic acid fraction compounds (NAFCs). Additionally, two model NA compounds, the simple single ring cyclohexane carboxylic acid (CHCA) and complex diamondoid 1-adamanatane carboxylic acid (ADA), were utilized to determine the influence of NA structure on degradation. T. harzianum degraded 14% of CHCA, 13% of ADA, and 23-47% of Merichem NAs. Additionally, Orbitrap mass spectrometry revealed a large change in Z-series within NAFCs. This removal and shift in composition correlated to a 59% and 52% drop in toxicity as per Microtox, for Merichem NAs and NAFCs respectively. This proof of concept experiment confirms that the fungal species T. harzianum can contribute to the biodegradation of complex dissolved organics found in OSPW, including cyclic and diamondoid structures.


Assuntos
Ácidos Carboxílicos/metabolismo , Recuperação e Remediação Ambiental/métodos , Campos de Petróleo e Gás , Trichoderma/metabolismo , Águas Residuárias/microbiologia , Poluentes Químicos da Água/metabolismo , Adamantano/química , Adamantano/metabolismo , Alberta , Biodegradação Ambiental , Ácidos Carboxílicos/química , Cicloexanos/química , Cicloexanos/metabolismo
20.
Chemosphere ; 256: 127092, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32559887

RESUMO

Although nitrogen removal from wastewater is essential to prevent eutrophication, the biological processes employed to this end are characterized by several disadvantages, including high energy consumption and the production of large quantities of sludge. Thus, in this study, the organic matter and nitrogen removal efficiencies of the new sulfate reduction, denitrification/anammox and partial nitrification (SRDAPN) process were examined using an anaerobic-anoxic-oxic biofilter reactor. The results showed that the organic matter removal efficiency of the new process at loading rate 1.0 kg COD/m3 per day was 97%. With a circulation flow from the oxic to the anoxic column that was 3 times influent, the nitrogen removal efficiency of the sulfur denitrification and nitrification (SRDN) process without anammox, was 66%, while that of the SRDAPN process with anammox was 76%. Additionally, nitrogen consumption by the anammox reaction in the anoxic column was 13.8% for nitrite-nitrogen and 10.5% for ammonium-nitrogen, and the withdrawal of excess sludge was not required throughout the 170 days of operation. Microbial community analysis showed that acetogenic sulfate reducing bacteria and acetoclastic methanogens coexisted in the anaerobic column, and in the anoxic column, the total relative abundance of anammox bacteria, including Candidatus Brocadia, which coexisted with heterotrophic denitrifying bacteria and sulfur denitrifying bacteria, was 17-18%. Thus, this study established the SRDAPN process as an energy saving and high removal efficiency process.


Assuntos
Sulfatos/química , Eliminação de Resíduos Líquidos/métodos , Compostos de Amônio , Bactérias , Reatores Biológicos/microbiologia , Desnitrificação , Nitrificação , Nitritos , Nitrogênio , Oxirredução , Esgotos/microbiologia , Enxofre , Águas Residuárias/química , Águas Residuárias/microbiologia
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