Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 490
Filter
1.
Chinese Journal of Biotechnology ; (12): 2719-2729, 2023.
Article in Chinese | WPRIM | ID: wpr-981228

ABSTRACT

To investigate the bioelectrochemical enhanced anaerobic ammonia oxidation (anammox) nitrogen removal process, a bioelectrochemical system with coupled anammox cathode was constructed using a dual-chamber microbial electrolysis cell (MEC). Specifically, a dark incubation batch experiment was conducted at 30 ℃ with different influent total nitrogen concentrations under an applied voltage of 0.2 V, and the enhanced denitrification mechanism was investigated by combining various characterization methods such as cyclic voltammetry, electrochemical impedance spectroscopy and high-throughput sequencing methods. The results showed that the total nitrogen removal rates of 96.9%±0.3%, 97.3%±0.4% and 99.0%±0.3% were obtained when the initial total nitrogen concentration was 200, 300 and 400 mg/L, respectively. In addition, the cathode electrode biofilm showed good electrochemical activity. High-throughput sequencing results showed that the applied voltage enriched other denitrifying functional groups, including Denitratisoma, Limnobacter, and ammonia oxidizing bacteria SM1A02 and Anaerolineaceae, Nitrosomonas europaea and Nitrospira, besides the anammox bacteria. These electrochemically active microorganisms comprised of ammonium oxidizing exoelectrogens (AOE) and denitrifying electrotrophs (DNE). Together with anammox bacteria Candidatus Brocadia, they constituted the microbial community structure of denitrification system. Enhanced direct interspecies electron transfer between AOE and DNE was the fundamental reason for the further improvement of the total nitrogen removal rate of the system.


Subject(s)
Denitrification , Wastewater , Anaerobic Ammonia Oxidation , Nitrogen , Oxidation-Reduction , Bioreactors/microbiology , Ammonium Compounds , Bacteria/genetics , Microbiota , Sewage
2.
Chinese Journal of Biotechnology ; (12): 1202-1216, 2023.
Article in Chinese | WPRIM | ID: wpr-970433

ABSTRACT

Biodegradation of pyridine pollutant by microorganisms is one of the economical and effective methods to solve the environmental pollution of pyridine under high salinity conditions. To this end, screening of microorganisms with pyridine degradation capability and high salinity tolerance is an important prerequisite. In this paper, a salt-resistant pyridine degradation bacterium was isolated from the activated sludge of Shanxi coking wastewater treatment plant, and identified as a bacterium belonging to Rhodococcus on the basis of colony morphology and 16S rDNA gene phylogenetic analysis. Salt tolerance experiment showed that strain LV4 could grow and degrade pyridine with the initial concentration of 500 mg/L completely in 0%-6% saline environment. However, when the salinity was higher than 4%, strain LV4 grew slowly and the degradation time of pyridine by strain LV4 was significantly prolonged. Scanning electron microscopy showed that the cell division of strain LV4 became slower, and more granular extracellular polymeric substance (EPS) was induced to secrete in high salinity environment. When the salinity was not higher than 4%, strain LV4 responded to the high salinity environment mainly through increasing the protein content in EPS. The optimum conditions for pyridine degradation by strain LV4 at 4% salinity were 30 ℃, pH 7.0 and 120 r/min (DO 10.30 mg/L). Under these optimal conditions, strain LV4 could completely degrade pyridine with an initial concentration of 500 mg/L at a maximum rate of (29.10±0.18) mg/(L·h) after 12 h adaptation period, and the total organic carbon (TOC) removal efficiency reached 88.36%, indicating that stain LV4 has a good mineralization effect on pyridine. By analyzing the intermediate products in pyridine degradation process, it was speculated that strain LV4 achieved pyridine ring opening and degradation mainly through two metabolic pathways: pyridine-ring hydroxylation and pyridine-ring hydrogenation. The rapid degradation of pyridine by strain LV4 in high salinity environment indicates its application potential in the pollution control of high salinity pyridine environment.


Subject(s)
Rhodococcus/genetics , Phylogeny , Extracellular Polymeric Substance Matrix/metabolism , Sewage , Biodegradation, Environmental , Pyridines/metabolism
3.
Chinese Journal of Biotechnology ; (12): 1026-1039, 2023.
Article in Chinese | WPRIM | ID: wpr-970420

ABSTRACT

The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.


Subject(s)
Wastewater/toxicity , Sewage/chemistry , Zinc Oxide/chemistry , Waste Disposal, Fluid , Nanoparticles/chemistry , Metal Nanoparticles/chemistry , Nitrogen/metabolism , Water Purification
4.
Chinese Journal of Biotechnology ; (12): 1009-1025, 2023.
Article in Chinese | WPRIM | ID: wpr-970419

ABSTRACT

Water eutrophication poses great threats to protection of water environment. Microbial remediation of water eutrophication has shown high efficiency, low consumption and no secondary pollution, thus becoming an important approach for ecological remediation. In recent years, researches on denitrifying phosphate accumulating organisms and their application in wastewater treatment processes have received increasing attention. Different from the traditional nitrogen and phosphorus removal process conducted by denitrifying bacteria and phosphate accumulating organisms, the denitrifying phosphate accumulating organisms can simultaneously remove nitrogen and phosphorus under alternated anaerobic and anoxic/aerobic conditions. It is worth noting that microorganisms capable of simultaneously removing nitrogen and phosphorus absolutely under aerobic conditions have been reported in recent years, but the mechanisms remain unclear. This review summarizes the species and characteristics of denitrifying phosphate accumulating organisms and the microorganisms capable of performing simultaneous nitrification-denitrification and phosphorous removal. Moreover, this review analyzes the relationship between nitrogen removal and phosphorus removal and the underlying mechanisms, discusses the challenges of denitrifying phosphorus removal, and prospects future research directions, with the aim to facilitate process improvement of denitrifying phosphate accumulating organisms.


Subject(s)
Phosphorus , Phosphates , Wastewater , Denitrification , Waste Disposal, Fluid , Nitrogen , Bioreactors/microbiology , Nitrification , Sewage
5.
Chinese Journal of Preventive Medicine ; (12): 674-678, 2023.
Article in Chinese | WPRIM | ID: wpr-984763

ABSTRACT

Objective: To estimate the consumption level of four drugs in Beijing using wastewater-based epidemiology (WBE). Methods: The primary sludge from one large wastewater treatment plants (WWTPs) was collected in Beijing from July 2020 to February 2021. The concentrations of codeine, methadone, ketamine and morphine in the sludge were detected through solid-phase extraction-liquid chromatography-tandem mass spectrometry. The consumption, prevalence and number of users of four drugs were estimated by using the WBE approach. Results: Among 416 sludge samples, codeine had the highest detection rate (82.93%, n=345) with a concentration [M (Q1, Q3)] of 0.40 (0.22-0.8) ng·g-1, and morphine had the lowest detection rate (28.37%,n=118) with a concentration [M (Q1, Q3)] of 0.13 (0.09, 0.17) ng·g-1. There was no significant difference in the consumption of the four drugs on working days and weekends (all P values>0.05). Drug consumption was significantly higher in winter than that in summer and autumn (all P values <0.05). The consumption [M (Q1, Q3)] of codeine, methadone, ketamine and morphine in winter was 24.9 (15.58, 38.6), 9.39 (4.57, 26.72), 9.84 (5.18, 19.45) and 5.67 (3.57, 13.77) μg·inhabitant-1·day-1, respectively. For these drugs, there was an upward trend in the average drug consumption during summer, autumn and winter (the Z values of the trend test were 3.23, 3.16, 2.19, and 3.32, respectively and all P values<0.05). The prevalence [M (Q1, Q3)] of codeine, methadone, ketamine and morphine were 0.0056% (0.003 4%, 0.009 2%), 0.0148% (0.009 6%, 0.026 7%),0.0333% (0.0210%, 0.0710%) and 0.0072% (0.003 8%, 0.011 7%), respectively. The estimated number of drug users [M (Q1, Q3)] was 918 (549, 1 511), 2 429 (1 578, 4 383), 5 451 (3 444, 11 642) and 1 173 (626, 1 925),respectively. Conclusion: Codeine, methadone, ketamine and morphine have been detected in the sludge of WWTPs in Beijing, and the consumption level of these drugs varies in different seasons.


Subject(s)
Humans , Beijing , Wastewater-Based Epidemiological Monitoring , Sewage/analysis , Wastewater , Ketamine/analysis , Codeine/analysis , Methadone/analysis , Water Pollutants, Chemical/analysis
6.
Braz. j. biol ; 83: e243874, 2023. graf
Article in English | LILACS, VETINDEX | ID: biblio-1285606

ABSTRACT

Abstract In recent days, cheapest alternative carbon source for fermentation purpose is desirable to minimize production cost. Xylanases have become attractive enzymes as their potential in bio-bleaching of pulp and paper industry. The objective of the present study was to identify the potential ability on the xylanase production by locally isolated Bacillus pumilus BS131 by using waste fiber sludge and wheat bran media under submerged fermentation. Culture growth conditions were optimized to obtain significant amount of xylanase. Maximum xylanase production was recorded after 72 hours of incubation at 30 °C and 7 pH with 4.0% substrate concentration. In the nutshell, the production of xylanase using inexpensive waste fiber sludge and wheat-bran as an alternative in place of expensive xylan substrate was more cost effective and environment friendly.


Resumo Nos últimos dias, a fonte alternativa de carbono mais barata para fins de fermentação é desejável para minimizar o custo de produção. As xilanases têm se tornado enzimas atraentes como seu potencial no biobranqueamento da indústria de papel e celulose. O objetivo do presente estudo foi identificar a capacidade potencial na produção de xilanase por Bacillus pumilus BS131 isolado localmente usando lodo de fibra residual e farelo de trigo em meio de fermentação submersa. As condições de crescimento da cultura foram otimizadas para obter uma quantidade significativa de xilanase. A produção máxima de xilanase foi registrada após 72 horas de incubação a 30 °C e pH 7 com concentração de substrato de 4,0%. Resumindo, a produção de xilanase usando lodo de fibra residual de baixo custo e farelo de trigo como uma alternativa no lugar do substrato de xilano caro foi mais econômica e ecológica.


Subject(s)
Bacillus/metabolism , Bacillus pumilus/metabolism , Sewage , Temperature , Dietary Fiber , Endo-1,4-beta Xylanases/metabolism , Fermentation , Hydrogen-Ion Concentration
7.
Chinese Journal of Biotechnology ; (12): 4517-4533, 2023.
Article in Chinese | WPRIM | ID: wpr-1008039

ABSTRACT

Anaerobic granular sludge (AnGS), a self-immobilized aggregate containing various functional microorganisms, is considered as a promising green process for wastewater treatment. AnGS has the advantages of high volume loading rate, simple process and low excess sludge generation, thus shows great technological and economical potentials. This review systematically summarizes the recent advances of the microbial community structure and function of anaerobic granular sludge, and discusses the factors affecting the formation and stability of anaerobic granular sludge from the perspective of microbiology. Moreover, future research directions of AnGS are prospected. This review is expected to facilitate the research and engineering application of AnGS.


Subject(s)
Sewage/chemistry , Waste Disposal, Fluid , Anaerobiosis , Microbiota , Water Purification , Bioreactors/microbiology
8.
Braz. j. biol ; 83: e248305, 2023. tab
Article in English | LILACS, VETINDEX | ID: biblio-1339359

ABSTRACT

Abstract Fertilization with dehydrated sewage sludge can speed up the recovery process of degraded areas due to nutrients concentration, favoring the development of pioneer plants such as Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) and the emergence of insects. This study aimed the evaluation of chewing, pollinating insects, predators, their ecological indices and relationships on A. auriculiformis plants fertilized with dehydrated sewage sludge. The experimental design was completely randomized with two treatments (with and without dehydrated sewage sludge) and 24 repetitions. The prevalence of chewing insects Parasyphraea sp. (Coleoptera: Chrysomelidae), Nasutitermes sp. (Blattodea: Termitidae), and Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae), defoliation, and ecological indices of abundance of Coleoptera and Orthoptera were observed on fertilized A. auriculiformis. Acacia auriculiformis plants, with a superior number of branches/tree, revealed greater abundance of Coleoptera and Orthoptera, species richness of pollinating insects, defoliation, numbers of Parasyphraea sp. and T. collaris. The ones with larger leaves/branches displayed greater abundance of species richness of Coleoptera and Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). Therefore, the use of A. auriculiformis plants, fertilized with dehydrated sewage sludge, is promising in the recovery of degraded areas due to the ecological indices increase of chewing and pollinators insects and spiders in the analyzed area.


Resumo A fertilização com lodo de esgoto desidratado pode acelerar o processo de recuperação de áreas degradadas devido à concentração de nutrientes, favorecendo o desenvolvimento de plantas pioneiras tais como Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) e de seus insetos. O objetivo deste trabalho foi avaliar os insetos mastigadores, polinizadores e predadores e seus índices e relações ecológicas em plantas de A. auriculiformis fertilizadas com lodo de esgoto desidratado, em área degradada, durante 24 meses. O delineamento foi inteiramente casualizados com dois tratamentos (com e sem adubação com lodo de esgoto desidratado) e 24 repetições (uma repetição = uma planta). O maior número de insetos mastigadores Parasyphraea sp. (Coleoptera: Chrysomelidae), Nasutitermes sp. (Blattodea: Termitidae) e Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae), de desfolha, e do índice ecológico abundância de Coleoptera e de Orthoptera foram maiores em plantas de A. auriculiformis fertilizadas do que nas não fertilizadas com lodo de esgoto desidratado. Plantas de A. auriculiformis, com maior quantidade de galhos/árvore, apresentaram maiores abundâncias de Coleoptera e Orthoptera, riqueza de espécies de insetos polinizadores, desfolha e números de Parasyphraea sp. e T. collaris, e as com maior folhas/galho os de riqueza de espécies de Coleoptera e Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). Por tanto, a utilização de A. auriculiformis, adubada com lodo de esgoto desidratado, é promissora na recuperação de áreas degradadas devido ao aumento dos índices ecológicos de insetos mastigadores, polinizadores e aranhas na área.


Subject(s)
Animals , Acacia , Fabaceae , Sewage , Fertilization , Insecta
9.
Article in Spanish | LILACS, CUMED | ID: biblio-1410306

ABSTRACT

En la actualidad la contaminación de las aguas terrestres es un grave problema ambiental. La industria farmacéutica es una de las que produce un mayor impacto por la gran variedad de químicos que aporta al agua; sus efluentes generalmente tienen asociadas elevadas cargas orgánicas no biodegradables. La preservación de la calidad de las aguas terrestres es un tema regulado por la legislación nacional, donde se exige la caracterización de las aguas residuales antes de su vertimiento con vistas a evaluar el impacto ambiental que producen y diseñar el sistema adecuado para su tratamiento. El Instituto Finlay de Vacunas, pertenece al grupo de BioCubaFarma, es una empresa de ciclo completo, cuenta con nueve instalaciones, cinco de ellas son generadoras de grandes volúmenes de aguas residuales industriales. El presente trabajo tiene el objetivo de presentar los resultados obtenidos en la evaluación de los parámetros físico-químico de los residuales líquidos del proceso productivo de conjugados monovalentes, para esto se muestrearon los residuales líquidos generados al final de cada etapa del proceso. Se determinaron los indicadores de contaminación: pH, temperatura, conductividad eléctrica, demanda química y bioquímica de oxígeno, fósforo total, nitrógeno total y sólidos sedimentables; los ensayos fueron realizados en el laboratorio de la Empresa Nacional de Servicios Técnicos de la Habana, acreditado para la realización de las caracterizaciones de aguas residuales. Los resultados fueron comparados con los límites máximos permisibles establecidos en la Norma Cubana NC-27:2012 de vertimiento de aguas residuales al alcantarillado, además se calculó el índice de biodegradabilidad. Se demostró que el pH, la conductividad eléctrica, demanda química de oxígeno y demanda bioquímica de oxígeno no cumplen con el vertido para la descarga al alcantarillado pudiendo impactar de manera negativa en los recursos hídricos(AU)


At present, the pollution of terrestrial waters is a serious environmental problem. The drug industry is one of those that produces a greater impact, due to the great variety of chemicals that can contribute to the water; its effluents generally have associated high non-biodegradable organic loads. The preservation of the quality of terrestrial waters is a subject regulated by legislation, where the characterization of wastewater is required before its discharge, since it allows evaluating the environmental impact it produces and designing the appropriate system for its treatment. The Finlay Vaccine Institute, belongs to the BioCubaFarma group, is a full cycle company, has nine facilities, five of them are generators of large volumes of industrial wastewater. The current work presents the results obtained in the evaluation of the physical-chemical parameters of the liquid waste from the production process of monovalent conjugates, for this the liquid waste generated at the end of each stage of the process was sampled. Pollution indicators were determined: pH, temperature, electrical conductivity, chemical and biochemical oxygen demand, total phosphorus, total nitrogen and sedimentable solids. The results were compared with the maximum permissible limits established in NC-27: 2012 for the discharge of wastewater. The biodegradability index was also calculated. It was shown that some of the determined parameters do not comply with the discharge to release to the sewer system, which could have a negative impact on water resources(AU)


Subject(s)
Humans , Sewage , Water Pollution/prevention & control , Pollution Indicators , Drug Industry , Wastewater Biological Characteristics , Water Quality/standards , Vaccines
10.
Chinese Journal of Biotechnology ; (12): 1351-1359, 2022.
Article in Chinese | WPRIM | ID: wpr-927785

ABSTRACT

Anaerobic ammonia oxidation (ANAMMOX) process is an efficient and low-cost biological nitrogen removal process. However, it still faces some challenges in mainstream applications due to the limitation of substrate types and nitrate accumulation. In recent years, the combined process of anammox has been widely studied to solve the above problems. In this paper, the combined processes of anammox developed in recent years are reviewed, and discussed from the process principle, advantages and disadvantages, influencing factors, process extensibility and the key bottlenecks existing in the promotion and application, as well as the relevant work of the subject group. Finally, we take an outlook on the development of the combined anaerobic ammonia oxidation process in municipal domestic wastewater treatment.


Subject(s)
Ammonium Compounds , Anaerobiosis , Bioreactors , Denitrification , Nitrogen , Oxidation-Reduction , Sewage , Wastewater
11.
Braz. j. biol ; 82: e246116, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1249222

ABSTRACT

The organization of the roots, ganglia and the peripheral distribution of the cranial nerves of the fully formed embryos of Oreochromis niloticus are examined in the transverse serial sections. These nerves carry fibers, which were also analyzed. The results of this study demonstrated that the glossopharyngeal nerve originates by means of only one root, which leaves the cranium through the glossopharyngeal foramen. This nerve gives fibers (visceromotor) to the first internal and external levator arcus branchialis muscles. There is a single epibranchial (petrosal) ganglion located extracranially. Nervus glossopharyngeus has three rami; pharyngeus, pretramticus and posttrematicus. The ramus pharyngeus carries only viscerosensory fibers; general for the pharyngeal epithelium and special ones for the pseudobranch. General viscerosensory fibers are also carried by rami pretrematicus and posttrematicus for the pharyngeal epithelial lining. The special sensory fibers are carried by the ramus pretrematicus for the taste buds and by ramus posttrematicus for the gill filaments. The ramus pretrematicus also carries visceromotor fibers for the first adductor arcus branchialis and to the first obliquus ventralis muscles.


A organização das raízes, gânglios e a distribuição periférica dos nervos cranianos dos embriões totalmente formados de Oreochromis niloticus são examinados nas seções transversais seriais. Esses nervos carregam fibras, que também foram analisadas. Os resultados deste estudo demonstraram que o nervo glossofaríngeo se origina por meio de apenas uma raiz, que sai do crânio pelo forame glossofaríngeo. Este nervo fornece fibras (visceromotoras) para os primeiros músculos levantadores do arco branquial interno e externo. Existe um único gânglio epibranquial (petroso) localizado extracranialmente. Nervus glossopharyngeus tem três ramos; faríngeo, pretramticus e póstrematicus. O ramo faríngeo contém apenas fibras viscerossensoriais ­ gerais para o epitélio faríngeo e especiais para o pseudobrânquio. Fibras viscerossensoriais gerais também são transportadas por ramos pretrematicus e posttrematicus para o revestimento epitelial da faringe. As fibras sensoriais especiais são transportadas pelo ramus pretrematicus para as papilas gustativas e pelo ramus posttrematicus para os filamentos branquiais. O ramo pretrematicus também carrega fibras visceromotoras para o primeiro adutor arcus branchialis e para o primeiro músculo oblíquo ventral.


Subject(s)
Humans , Animals , Water Pollutants, Chemical/analysis , Nematoda , Sewage , Tunisia , Environmental Monitoring , Geologic Sediments , Industry
12.
Braz. j. biol ; 82: e234471, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1153460

ABSTRACT

High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.


Altas doses de antibióticos utilizados em hospitais podem afetar a composição microbiana dos esgotos, selecionando bactérias resistentes. Nesse sentido, avaliamos o perfil de resistência a antibióticos e o fenótipo multirresistente de bactérias isoladas em esgoto de um hospital terciário no interior do estado de São Paulo, Brasil. Para o isolamento de bactérias, foram semeados 10 µL das amostras de esgoto em meios de cultura seletivos e os isolados foram identificados usando o sistema automatizado VITEK-2. O teste de sensibilidade aos antibióticos foi realizado por disco-difusão em ágar. Elevadas porcentagens de resistência foram encontradas para amoxicilina, ampicilina, ceftazidima, clindamicina, vancomicina e o fenótipo multirresistente (MDR) foi atribuído a 60,7% dos isolados. Nossos resultados mostram bactérias classificadas como prioridade crítica/alta pela Lista de Patógenos Prioritários da OMS (Enterococcus e Staphylococcus aureus resistentes à vancomicina e Enterobacteriaceae resistentes aos carbapenêmicos) no esgoto hospitalar. Sendo assim, implementação de tecnologias de desinfecção do esgoto hospitalar reduziriam a carga bacteriana no esgoto que chegará às estações de tratamento de esgoto urbanas, minimizando a contaminação dos ecossistemas hídricos receptores e a disseminação da resistência bacteriana no ambiente.


Subject(s)
Sewage , Bacteria/genetics , Phenotype , Brazil , Microbial Sensitivity Tests , Tertiary Care Centers
13.
Braz. j. biol ; 82: 1-6, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1468419

ABSTRACT

High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.


Altas doses de antibióticos utilizados em hospitais podem afetar a composição microbiana dos esgotos, selecionando bactérias resistentes. Nesse sentido, avaliamos o perfil de resistência a antibióticos e o fenótipo multirresistente de bactérias isoladas em esgoto de um hospital terciário no interior do estado de São Paulo, Brasil. Para o isolamento de bactérias, foram semeados 10 µL das amostras de esgoto em meios de cultura seletivos e os isolados foram identificados usando o sistema automatizado VITEK-2. O teste de sensibilidade aos antibióticos foi realizado por disco-difusão em ágar. Elevadas porcentagens de resistência foram encontradas para amoxicilina, ampicilina, ceftazidima, clindamicina, vancomicina e o fenótipo multirresistente (MDR) foi atribuído a 60,7% dos isolados. Nossos resultados mostram bactérias classificadas como prioridade crítica/alta pela Lista de Patógenos Prioritários da OMS (Enterococcus e Staphylococcus aureus resistentes à vancomicina e Enterobacteriaceae resistentes aos carbapenêmicos) no esgoto hospitalar. Sendo assim, implementação de tecnologias de desinfecção do esgoto hospitalar reduziriam a carga bacteriana no esgoto que chegará às estações de tratamento de esgoto urbanas, minimizando a contaminação dos ecossistemas hídricos receptores e a disseminação da resistência bacteriana no ambiente.


Subject(s)
Enterococcus/pathogenicity , Sewage/analysis , Water Microbiology/standards , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicity , Drug Resistance, Microbial , Staphylococcus aureus/pathogenicity
14.
Braz. j. biol ; 82: e240943, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1278469

ABSTRACT

The emergence of multi-drug resistant (MDR) bacterial strains, which are posing a global health threat has developed the interest of scientists to use bacteriophages instead of conventional antibiotics therapy. In light of an increased interest in the use of phage as a bacterial control agent, the study aimed to isolate and characterize lytic phages from sewage effluent. During the current study, bacteriophage AS1 was isolated from sewage effluent against E.coli S2. The lytic activity of phageAS1 was limited to E.coli S2 strain showing monovalent behavior. The calculated phage titer was 3.5×109 pfu/ml. PhageAS1 was stable at a wide range of pH and temperature. The maximum stability was recorded at 37ºC and pH 7.0, while showing its normal lytic activity at temperature 60ºC and from pH 5.0 to11.0 respectively. At temperature 70ºC, phage activity was somewhat reduced whereas, further increase in temperature and decrease or increase in pH completely inactivated the phage. From the current study, it was concluded that waste water is a best source for finding bacteriophages against multi-drug resistant bacterial strains and can be used as bacterial control agent.


O surgimento de cepas bacterianas multirresistentes (MDR), que representam uma ameaça global à saúde, desenvolveu o interesse dos cientistas em usar bacteriófagos em vez da terapia convencional com antibióticos. Diante do crescente interesse no uso de fago como agente de controle bacteriano, o estudo visou isolar e caracterizar fagos líticos de efluente de esgoto. Durante o estudo atual, o bacteriófago AS1 foi isolado de efluente de esgoto contra E. coli S2. A atividade lítica de phageAS1 foi limitada à cepa E. coli S2, apresentando comportamento monovalente. O título de fago calculado foi de 3,5 x 109 ufp/ml. PhageAS1 foi estável em uma ampla faixa de pH e temperatura. A estabilidade máxima foi registrada a 37ºC e pH 7,0, enquanto mostrou atividade lítica normal em temperatura de 60ºC e pH 5,0 a 11,0, respectivamente. Na temperatura de 70ºC, a atividade do fago foi um pouco reduzida, enquanto o aumento adicional da temperatura e a diminuição ou aumento do pH inativaram completamente o fago. Com base no estudo atual, concluiu-se que a água residual é a melhor fonte para encontrar bacteriófagos contra cepas bacterianas multirresistentes e pode ser usada como agente de controle bacteriano.


Subject(s)
Sewage , Bacteriophages , Pakistan , Temperature , Coliphages
15.
São Paulo; s.n; 2022. 235 p.
Thesis in Portuguese | LILACS | ID: biblio-1354322

ABSTRACT

O comportamento e o destino dos fármacos e seus metabólitos no meio aquático, assim como seus efeitos na biota e saúde humana, têm sido objeto de estudos em âmbito global. No entanto, poucas pesquisas relacionam parâmetros operacionais e físico-químicos à remoção dos fármacos em Estações de Tratamento de Esgotos (ETE). Os principais processos responsáveis pela redução da concentração destes contaminantes na fase aquosa, durante o tratamento de esgotos, são a biodegradação e a sorção à fase sólida. No que diz respeito à qualidade dos lodos produzidos, um aspecto ainda pouco estudado refere-se à identificação de poluentes emergentes, substâncias presentes no ambiente e que usualmente não são monitoradas, especialmente pela ausência de regulamentação legal nos países, podendo apresentar risco potencial à saúde humana e ao meio ambiente. Desse modo, o presente estudo tem por objetivo identificar, quantificar e avaliar a eficiência de remoção de fármacos presentes em biossólidos provenientes de uma ETE, antes e após o processo de compostagem, utilizando técnicas de cromatografia UFLCTM e espectrometria MS-MS, e avaliar os fármacos escolhidos para estudo, com base no modelo QSAR (ECOSAR-EPA), visando identificar o potencial de bioacumulação e ecotoxicidade dessas substâncias no ambiente, de acordo com as propriedades físico-químicas. De acordo com os resultados obtidos observa-se que houve redução na concentração dos compostos avaliados, indicando tendência à biodegradação ou redução na biodisposição dos mesmos. O processo de compostagem estudado, além de mostrar-se adequado para a produção de um biossólido com características compatíveis com as requeridas para o uso agrícola, possibilitou constatar a eficiência do processo como alternativa para o tratamento desses contaminantes presentes no lodo de esgotos. Possíveis interações que possam ocorrer com outros fármacos presentes no ambiente, em relação a concentrações residuais e metabólitos gerados, os quais não foram investigados no presente estudo, apontam para a necessidade de estudos em relação aos mecanismos farmacocinéticos e farmacodinâmicos para entendimento dos mecanismos de reação envolvidos na formação e toxicidade de seus metabólitos. A presença destes compostos nas várias matrizes ambientais denota a importância das pesquisas nessa área, e a adoção de boas práticas operacionais visando garantir a qualidade e a segurança requeridas na utilização benéfica do lodo de esgotos, principalmente para fins agrícolas.


The behavior and fate of drugs and their metabolites in the aquatic environment, as well as their effects on biota and human health, have been the object of studies on a global scale. However, few research relate operational and physicochemical parameters to the removal of drugs in Sewage Treatment Plants (ETE). The main processes responsible for reducing the concentration of these contaminants in the aqueous phase, during sewage treatment, are biodegradation and sorption to the solid phase. Regarding the quality of the sludge produced, an aspect that has still been poorly studied refers to the identification of emerging pollutants, substances present in the environment that are usually not monitored, especially due to the lack of legal regulations in the countries, which may present a potential risk to health. human and the environment. Thus, this study aims to identify, quantify, and evaluate the efficiency of removal of drugs present in biosolids from an ETE, before and after the composting process, using UFLCTM chromatography and MS-MS spectrometry techniques, and evaluate the drugs chosen for study, based on the QSAR model (ECOSAR-EPA), to identify the bioaccumulation potential and ecotoxicity of these substances in the environment, according to their physicochemical properties. According to the results obtained, it is observed that there was a reduction in the concentration of the compounds evaluated, indicating a tendency to biodegradation or a reduction in their biodisposition. The composting process studied, in addition to being suitable to produce biosolids with characteristics compatible with those required for agricultural use, made it possible to verify the efficiency of the process as an alternative for the treatment of these contaminants present in sewage sludge. Possible interactions that may occur with other drugs present in the environment, in relation to residual concentrations and generated metabolites, which were not investigated in this study, point to the need for studies in relation to pharmacokinetic and pharmacodynamic mechanisms to understand the reaction mechanisms involved in the formation and toxicity of its metabolites. The presence of these compounds in the various environmental matrices denotes the importance of research in this area, and the adoption of good operational practices to ensure the quality and safety required in the beneficial use of sewage sludge, mainly for agricultural purposes.


Subject(s)
Sewage , Pharmaceutical Preparations , Composting , Biosolids , Wastewater Treatment Plants
16.
Hist. ciênc. saúde-Manguinhos ; 28(3): 869-874, jul.-set. 2021.
Article in Spanish | LILACS | ID: biblio-1339968

ABSTRACT

Resumen Este artículo describe el inicio de las preocupaciones sanitarias vinculadas a las epidemias ocurridas durante el siglo XX en La Pampa, provincia argentina. Las epidemias, como las de la viruela, fueron un estímulo para estas políticas que frecuentemente tuvieron origen en Buenos Aires, la capital del país. El contagio de muchas epidemias dependía de carencias de infraestructura: agua, desagüe y desecho adecuado de basuras, de la ausencia de un número suficiente de trabajadores de salud, de la presencia de vectores transmisores de enfermedades como los mosquitos y, en última instancia, de la pobreza. La experiencia histórica descrita en este texto resalta la importancia de analizar el impacto del SARS-CoV-2 más allá de las grandes ciudades.


Abstract This article describes the emergence of health concerns relating to the epidemics that occurred during the twentieth century in La Pampa, a province in Argentina. Epidemics such as smallpox drove such policies, which frequently originated in Buenos Aires, the country's capital. The spread of many epidemics was due to shortages: water, sewage and adequate refuse disposal, an insufficient number of health care workers, the presence of disease transmission vectors such as mosquitos, and, ultimately, poverty. The historical experience described in this text highlights the importance of analyzing the impact of SARS-CoV-2 beyond the big cities.


Subject(s)
Humans , Animals , Male , Female , Child , History, 20th Century , Smallpox/history , Epidemics/history , COVID-19/history , Argentina/epidemiology , Poverty/history , Sewage , Water Supply/history , Smallpox/prevention & control , Smallpox/epidemiology , Indians, South American/history , Indians, South American/statistics & numerical data , Refuse Disposal/history , Vaccination/history , Vaccination/legislation & jurisprudence , Cities/history , Cities/epidemiology , Health Personnel/history , Health Personnel/statistics & numerical data , Disease Eradication/history , Disease Eradication/organization & administration , COVID-19/epidemiology , Health Policy/history , Health Policy/legislation & jurisprudence , Insect Vectors , Military Personnel/history
17.
Chinese Journal of Biotechnology ; (12): 3653-3662, 2021.
Article in Chinese | WPRIM | ID: wpr-921454

ABSTRACT

Microorganisms are the dominant players driving the degradation and transformation of chloramphenicol (CAP) in the environment. However, little bacterial strains are able to efficiently degrade and mineralize CAP, and the CAP degrading pathways mediated by oxidative reactions remain unclear. In this study, a highly efficient CAP-degrading microbial consortium, which mainly consists of Rhodococcus (relative abundance >70%), was obtained through an enrichment process using CAP-contaminated activated sludge as the inoculum. A bacterial strain CAP-2 capable of efficiently degrading CAP was isolated from the consortium and identified as Rhodococcus sp. by 16S rRNA gene analysis. Strain CAP-2 can efficiently degrade CAP under different nutrient conditions. Based on the biotransformation characteristics of the detected metabolite p-nitrobenzoic acid and the reported metabolites p-nitrobenzaldehyde and protocatechuate by strain CAP-2, a new oxidative pathway for the degradation of CAP was proposed. The side chain of CAP was oxidized and broken to generate p-nitrobenzaldehyde, which was further oxidized to p-nitrobenzoic acid. Strain CAP-2 can be used to further study the molecular mechanism of CAP catabolism, and has the potential to be used in in situ bioremediation of CAP-contaminated environment.


Subject(s)
Biodegradation, Environmental , Chloramphenicol , RNA, Ribosomal, 16S/genetics , Rhodococcus/genetics , Sewage
18.
Chinese Journal of Biotechnology ; (12): 3459-3474, 2021.
Article in Chinese | WPRIM | ID: wpr-921441

ABSTRACT

Sulfonamides (SAs) are a kind of antibiotics widely used in medical treatment and livestock breeding. However, they have poor degradability in human and animal intestines, and will enter the sewage treatment system through the discharge of feces and urine. The aerobic activated sludge (AAS) in wastewater treatment plant was found to be able to effectively transform SAs. This article summarizes the advances in biodegradation of SAs in aerobic activated sludge system, which includes the biodegradation mechanisms, the main biodegradation pathways, and the environmental factors affecting the degradation efficiency. Challenges encountered in the current research were discussed, with the aim to provide scientific basis for optimizing the biodegradation of SAs in wastewater treatment process.


Subject(s)
Humans , Anti-Bacterial Agents , Biodegradation, Environmental , Sewage , Sulfonamides , Water Pollutants, Chemical/analysis
19.
Chinese Journal of Biotechnology ; (12): 448-460, 2021.
Article in Chinese | WPRIM | ID: wpr-878574

ABSTRACT

Resource utilization is an effective way to cope with the rapid increase of kitchen waste and excess sludge, and volatile fatty acids produced by anaerobic fermentation is an important way of recycling organic waste. However, the single substrate limits the efficient production of volatile fatty acids. In recent years, volatile fatty acids produced by anaerobic co-fermentation using different substrates has been widely studied and applied. In this paper, we analyze the characteristics of fermentation to produce acid using kitchen waste and excess sludge alone or mixture. Influences of environmental factors and microbial community structure on the type and yield of volatile fatty acids in the anaerobic fermentation system are discussed in detail. Moreover, we propose future research directions, to provide a reference for recycling kitchen waste and excess sludge.


Subject(s)
Anaerobiosis , Bioreactors , Fatty Acids, Volatile , Fermentation , Hydrogen-Ion Concentration , Microbiota , Organic Chemicals , Sewage
20.
Chinese Journal of Biotechnology ; (12): 149-162, 2021.
Article in Chinese | WPRIM | ID: wpr-878550

ABSTRACT

Polyhydroxyalkanoates (PHA) synthesis by activated sludge using volatile fatty acids (VFAs) in fermentation liquid of excess sludge as carbon source is a hotspot in the field of environmental biotechnology. However, there is no unified conclusion on the effects of non-VFAs, mainly dissolved organic matter (DOM), on PHA production. Thus, this critical review mainly introduces the main characteristics and common analysis methods of DOM in anaerobic fermentation liquid. The effects of DOM on PHA production are analyzed from the aspects of microbiology, metabolic regulation and sludge properties. The results of different studies showed that high concentration of DOM is bad for PHA production, but an appropriate amount of DOM is conducive to the stability of sludge properties, reducing the final PHA purification cost. Finally, suitable strategies were proposed to regulate the PHA synthesis by activated sludge with DOM for PHA production by anaerobic fermentation liquid.


Subject(s)
Anaerobiosis , Bioreactors , Fatty Acids, Volatile , Fermentation , Polyhydroxyalkanoates , Sewage
SELECTION OF CITATIONS
SEARCH DETAIL