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1.
Bioresour Technol ; 311: 123501, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32416492

RESUMO

The accumulation of volatile fatty acids (VFAs) can decrease reactor pH and inhibit methane-producing process. For the first time, photosynthetic bacteria (PSB) were used to recover from VFAs inhibition (pH 6.0) of an anaerobic digestion system. After adding PSB for 12 days with and without light condition, the methane content recovered from 33.3% to 60.5% and from 32.1% to 59.3%, respectively; the pH increased to 7.1 and 6.8, respectively, the system alkalinity rapidly increased to 2238 and 1921 mg/L, respectively; the sCOD decreased from 5600 to 995 mg/L and from 5575 to 2025 mg/L, respectively; and the contents of formic acid, acetic acid, propionic acid and total VFA were greatly reduced. Microbial analysis found that PSB bioaugmentation could maintain microbial diversity of the system. PSB bioaugmentation could effectively relieve acids accumulation and stimulate methane production especially under light condition. It is also found that light could accelerate recovery with or without bioaugmentation.


Assuntos
Reatores Biológicos , Ácidos Graxos Voláteis , Anaerobiose , Bactérias , Bactérias Anaeróbias , Metano
2.
Orv Hetil ; 161(19): 797-803, 2020 05 01.
Artigo em Húngaro | MEDLINE | ID: mdl-32364362

RESUMO

Introduction: Anaerobes play an important etiological role in invasive infections, and may be clinically significant pathogens in bloodstream infections and septicemia, but little data are available on their true prevalence in Hungary. Aim: The aim of this study was to determine the prevalence of anaerobic bacteria in the blood culture samples received at the Institute of Clinical Microbiology, University of Szeged, retrospectively. Method: Blood culture samples received at the Institute were analyzed over a 5-year period (01. 01. 2013-31. 12. 2017); the comparison was based on a similar study (2005-2009) conducted in the same region. Results: Between 2013 and 2017, our Institute received an average of 23,274 ± 2,756 blood culture bottles, of which an average of 10.5% were positive and 0.4% were positive for anaerobes (3.5-3.8/1000 bottles). Clinically significant anaerobic pathogens were predominantly Bacteroides fragilis group (39.9%) and Clostridium species (32.8%). Conclusion: Despite their relatively low numbers, anaerobic bacteria are considered important etiologic factors in bloodstream infections. Our results highlight the importance of modern identification methods in adequate anaerobic diagnostics. Orv Hetil. 2020; 161(19): 797-803.


Assuntos
Bacteriemia/microbiologia , Bactérias Anaeróbias , Infecções Bacterianas/epidemiologia , Sepse/microbiologia , Bacteriemia/epidemiologia , Bactérias Anaeróbias/patogenicidade , Hospitais Universitários , Humanos , Hungria/epidemiologia , Incidência , Infecções , Estudos Retrospectivos , Sepse/epidemiologia
3.
Water Sci Technol ; 81(3): 544-549, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32385208

RESUMO

Nine anaerobic sludges were screened to obtain the most effective methanogenic inoculum for the anaerobic treatment of groundwater that is contaminated with tetrachloroethene (PCE) or trichloroethene (TCE). The selection was based on the toxicity of PCE or TCE to acetoclastic methanogens in different sludges. The effects of two biological factors, sludge origin and specific acetoclastic methanogenic activity, and a physical factor, specific surface area of sludge, on the degree of inhibition were examined and compared. The fifty percent inhibition concentrations (IC50) of PCE and TCE that were obtained from 30 °C batch inhibition tests ranged from 0.18 to 0.41 and 1.71 to 3.31 mM, respectively, for the examined sludges. The toxicity of the contaminants to anaerobic sludges did not depend on the two biological factors but was closely correlated with the specific surface area of sludge. Suspended sludges, which have higher specific surface areas than granular sludges, suffered much greater inhibition. This paper suggests the use of anaerobic granular sludges as inocula in bioreactors for treating PCE- and TCE-contaminated groundwater to reduce the effect of their inhibition.


Assuntos
Tetracloroetileno , Tricloroetileno , Anaerobiose , Bactérias Anaeróbias , Reatores Biológicos , Esgotos
4.
Bioresour Technol ; 302: 122865, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32004814

RESUMO

Fermentative caproate production from wastewater is attractive but is currently limited by the low product purity and concentration. In this work, continuous, selective production of caproate from acetate and ethanol, the common products of wastewater anaerobic fermentation, was achieved in an anaerobic membrane bioreactor (AnMBR). The reactor was continuously operated for over 522 days without need for chemical cleaning. With an ethanol-to-acetate ratio of 3.0, the effluent caproate concentration was 2.62 g/L on average and the caproate ratio in liquid products reached 74%. Further raising the influent ethanol content slightly increased the effluent caproate level but lowered the product selectivity and resulted in microbial inhibition. The Clostridia (the major caproate-producing bacteria) and Methanobacterium species (which consume hydrogen to alleviate microbial inhibition) was significantly enriched in the acclimated sludge. Our results imply a great potential of utilizing AnMBR to recover caproate from the effluent of wastewater acidogenic fermentation process.


Assuntos
Reatores Biológicos , Caproatos , Anaerobiose , Bactérias Anaeróbias , Fermentação
5.
Water Res ; 174: 115599, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32086134

RESUMO

The optimal automatic start-up of anaerobic digesters has remained an elusive problem over the years to be solved at the lowest possible costs, including that of process monitoring. In this work, a non-linear model predictive control (NMPC) system was developed, under two proposed configurations, for the optimal start-up of anaerobic digesters treating soluble non-recalcitrant substrates. The minimum set of low cost practical control variables (CVs) selected for process start-up include (i) the effluent quality as acetate COD, (ii) the level of aceticlastic methanogenic biomass in the reactor, and (iii) the methane production rate (only for one of the NMPC configurations). The manipulated variables (MVs) consist of the volumetric inflow rates of the organic substrate, dilution water, and of a possible concentrated alkali addition. To be able to apply the above selected CVs (technically and economically feasible to measure/estimate), a simplified tailored AD model was specifically designed as the prediction model, integral part of the NMPC system. The NMPC system developed was evaluated for a case scenario consisting of the automatic start-up of a high rate AD reactor treating a readily biodegradable carbohydrate based substrate. The AD plant was virtually represented by the complex Anaerobic Digestion Model No. 1. Compared to other manual start-up strategies, the two configurations of the NMPC developed appeared to reach the target methane production rate faster (39 and 18 days for the NMPC versus 70-75 days for the manual strategies) together with an overall superior CV set-point tracking error performance. Interestingly, the two configurations of the NMPC developed appear to propose two very different, almost opposite, start-up feeding strategies to both eventually start-up the reactor successfully with no process destabilizations throughout. A number of practical scenarios were also considered to evaluate the NMPC configurations for robustness and any possible improvements. These tests indicate that the NMPC objective function formulation is a key factor of the success and robustness exhibited during start-up.


Assuntos
Reatores Biológicos , Euryarchaeota , Anaerobiose , Bactérias Anaeróbias , Biomassa , Metano
6.
BMC Infect Dis ; 20(1): 142, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059701

RESUMO

BACKGROUND: Obligate anaerobes usually account for less than 10% of bacteria recovered from blood cultures (BC). The relevance of routine use of the anaerobic bottle is under debate. The aim of this study was to evaluate the utility of anaerobic bottles for the diagnosis of bloodstream infections (BSI). METHODS: We conducted a 6-month, retrospective, monocentric study in a tertiary hospital. All positive BC were grouped into a single episode of bacteremia when drawn within 7 consecutive days. Bacteremia were classified into contaminants and BSI. Charts of patients with BSI due to obligate anaerobes were studied. RESULTS: A total of 19,739 blood cultures were collected, 2341 of which (11.9%) were positive. Anaerobic bottles were positive in 1528 (65.3%) of all positive BC but were positive alone (aerobic bottles negative) in 369 (15.8%). Overall 1081 episodes of bacteremia were identified, of which 209 (19.3%) had positive anaerobic bottles alone. The majority 126/209 (60.3%) were contaminants and 83 (39.7%) were BSI. BSI due to facultative anaerobes, obligate aerobes and obligate anaerobes were identified in 67 (80.7%), 3 (3.6%) and 13 (15.7%) of these 83 episodes, respectively. BSI due to obligate anaerobic bacteria were reported in 9 patients with gastro-intestinal disease, in 3 with febrile neutropenia and in 1 burned patient. CONCLUSIONS: Anaerobic bottles contributed to the diagnosis of a significant number of episodes of bacteremia. Isolated bacteria were mostly contaminants and non-obligate anaerobic pathogens. Rare BSI due to obligate anaerobes were reported mainly in patients with gastro-intestinal disorders and during febrile neutropenia.


Assuntos
Bacteriemia/microbiologia , Bactérias Aeróbias/isolamento & purificação , Bactérias Anaeróbias/isolamento & purificação , Hemocultura/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Bacteriemia/etiologia , Bactérias Aeróbias/patogenicidade , Bactérias Anaeróbias/patogenicidade , Hemocultura/métodos , Queimaduras/complicações , Queimaduras/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neutropenia/microbiologia , Estudos Retrospectivos , Centros de Atenção Terciária
7.
Nat Rev Urol ; 17(4): 232-250, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32071434

RESUMO

The female reproductive tract (FRT), similar to other mucosal sites, harbours a site-specific microbiome, which has an essential role in maintaining health and homeostasis. In the majority of women of reproductive age, the microbiota of the lower FRT (vagina and cervix) microenvironment is dominated by Lactobacillus species, which benefit the host through symbiotic relationships. By contrast, the upper FRT (uterus, Fallopian tubes and ovaries) might be sterile in healthy individuals or contain a low-biomass microbiome with a diverse mixture of microorganisms. When dysbiosis occurs, altered immune and metabolic signalling can affect hallmarks of cancer, including chronic inflammation, epithelial barrier breach, changes in cellular proliferation and apoptosis, genome instability, angiogenesis and metabolic dysregulation. These pathophysiological changes might lead to gynaecological cancer. Emerging evidence shows that genital dysbiosis and/or specific bacteria might have an active role in the development and/or progression and metastasis of gynaecological malignancies, such as cervical, endometrial and ovarian cancers, through direct and indirect mechanisms, including modulation of oestrogen metabolism. Cancer therapies might also alter microbiota at sites throughout the body. Reciprocally, microbiota composition can influence the efficacy and toxic effects of cancer therapies, as well as quality of life following cancer treatment. Modulation of the microbiome via probiotics or microbiota transplant might prove useful in improving responsiveness to cancer treatment and quality of life. Elucidating these complex host-microbiome interactions, including the crosstalk between distal and local sites, will translate into interventions for prevention, therapeutic efficacy and toxic effects to enhance health outcomes for women with gynaecological cancers.


Assuntos
Carcinogênese , Disbiose/microbiologia , Neoplasias dos Genitais Femininos/microbiologia , Genitália Feminina/microbiologia , Microbiota/fisiologia , Anti-Infecciosos/uso terapêutico , Bactérias Anaeróbias , Colo do Útero/microbiologia , Disbiose/metabolismo , Estrogênios/metabolismo , Tubas Uterinas/microbiologia , Feminino , Microbioma Gastrointestinal , Neoplasias dos Genitais Femininos/metabolismo , Neoplasias dos Genitais Femininos/prevenção & controle , Neoplasias dos Genitais Femininos/terapia , Genitália Feminina/metabolismo , Humanos , Lactobacillus , Ovário/microbiologia , Probióticos/uso terapêutico , Útero/microbiologia , Vagina/microbiologia
8.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-32009018

RESUMO

We previously demonstrated that a simple modification in the preparation of agar media, i.e., autoclaving phosphate and agar separately (termed the "PS protocol"), improved the culturability of aerobic microorganisms by reducing the generation of reactive oxygen species. We herein investigated the effects of the PS protocol on the cultivation of anaerobic microorganisms using sludge from a wastewater treatment system as a microbial source. The application of the PS protocol increased colony numbers and the frequency of phylogenetically novel isolates under aerobic, nitrate reduction, and fermentation conditions. The PS protocol is useful for isolating both aerobic and anaerobic microorganisms.


Assuntos
Bactérias Anaeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/isolamento & purificação , Técnicas Bacteriológicas/métodos , Meios de Cultura/química , Ágar , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/metabolismo , Contagem de Colônia Microbiana , Fermentação , Nitratos/metabolismo , Fosfatos , Filogenia , RNA Ribossômico 16S/genética , Esgotos/microbiologia , Esterilização
9.
BMC Infect Dis ; 20(1): 99, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32007106

RESUMO

BACKGROUND: The identification of the pathogens in pleural effusion has mainly relied on conventional bacterial culture or single species polymerase chain reaction (PCR), both with relatively low sensitivity. We investigated the efficacy of a commercially available multiplex bacterial PCR assay developed for pneumonia to identify the pathogens involved in pleural infection, particularly empyema. METHODS: A prospective, monocentric, observational study including 194 patients with pleural effusion. Patients were evaluated based on imaging, laboratory values, pleura ultrasound and results of thoracentesis including conventional microbiology studies during hospitalisation. Multiplex bacterial PCR (Curetis Unyvero p55) was performed in batch and had no influence on therapeutic decisions. RESULTS: Overall, there were 51/197 cases with transudate and 146/197 with exudate. In 42% (n = 90/214) there was a clinical suspicion of parapneumonic effusion and the final clinical diagnosis of empyema was made in 29% (n = 61/214) of all cases. The most common microorganisms identified in the cases diagnosed with empyema were anaerobes [31] followed by gram-positive cocci [10] and gram-negative rods [4]. The multiplex PCR assay identified more of the pathogens on the panel than the conventional methods (23.3% (7/30) vs. 6.7% (2/30), p = 0.008). CONCLUSION: The multiplex PCR-based assay had a higher sensitivity and specificity than conventional microbiology when only the pathogens on the pneumonia panel were taken into account. A dedicated pleural empyema multiplex PCR panel including anaerobes would be needed to cover most common pathogens involved in pleural infection.


Assuntos
Empiema Pleural/microbiologia , Reação em Cadeia da Polimerase Multiplex/métodos , Derrame Pleural/microbiologia , Idoso , Idoso de 80 Anos ou mais , Bactérias Anaeróbias/genética , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Estudos de Coortes , Empiema Pleural/tratamento farmacológico , Exsudatos e Transudatos/microbiologia , Feminino , Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pleural/tratamento farmacológico , Derrame Pleural/mortalidade , Estudos Prospectivos
10.
PLoS One ; 15(1): e0215341, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31945063

RESUMO

Geobacter sulfurreducens was originally considered a strict anaerobe. However, this bacterium was later shown to not only tolerate exposure to oxygen but also to use it as terminal electron acceptor. Research performed has so far only revealed the general ability of G. sulfurreducens to reduce oxygen, but the oxygen uptake rate has not been quantified yet, nor has evidence been provided as to how the bacterium achieves oxygen reduction. Therefore, microaerobic growth of G. sulfurreducens was investigated here with better defined operating conditions as previously performed and a transcriptome analysis was performed to elucidate possible metabolic mechanisms important for oxygen reduction in G. sulfurreducens. The investigations revealed that cell growth with oxygen is possible to the same extent as with fumarate if the maximum specific oxygen uptake rate (sOUR) of 95 mgO2 gCDW-1 h-1 is not surpassed. Hereby, the entire amount of introduced oxygen is reduced. When oxygen concentrations are too high, cell growth is completely inhibited and there is no partial oxygen consumption. Transcriptome analysis suggests a menaquinol oxidase to be the enzyme responsible for oxygen reduction. Transcriptome analysis has further revealed three different survival strategies, depending on the oxygen concentration present. When prompted with small amounts of oxygen, G. sulfurreducens will try to escape the microaerobic area; if oxygen concentrations are higher, cells will focus on rapid and complete oxygen reduction coupled to cell growth; and ultimately cells will form protective layers if a complete reduction becomes impossible. The results presented here have important implications for understanding how G. sulfurreducens survives exposure to oxygen.


Assuntos
Bactérias Aeróbias/genética , Proteínas de Bactérias/genética , Geobacter/genética , Transcriptoma/genética , Bactérias Aeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/genética , Compostos Férricos/metabolismo , Fumaratos/metabolismo , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica/genética , Geobacter/crescimento & desenvolvimento , Oxirredução , Oxigênio/metabolismo
11.
Chemosphere ; 246: 125753, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31901528

RESUMO

Granules which could efficiently mineralize azo dyes were cultivated through immobilization of aerobic degradation strains in a core composed of anaerobic decolorization cultures. The core was obtained in a up-flow anaerobic sludge blanket (UASB) reactor incubated with anaerobic decolorization bacteria. Aerobic degradation strains were then grown on the surface of the anaerobic core in a sequencing batch reactor (SBR). Three of the granules' surface layers demonstrated the occurrence of immobilization. The granulation process was monitored with 16S rDNA high throughput sequencing. Anaerobic decolorization cultures belonging to the genera of unclassified, Levilinea, and Petrimonas and the aerobic degradation genera of Thauera, unclassified, Thermomonas, and Ottowia were successfully fixed in the granules. The obtained granules were capable of decolorizing azo dyes under anaerobic situation, and the generated aromatic amines were then completely mineralized in aerated environment. Comparative studies on the relationship between removed contaminates and typical components concentrations in low to high strength azo dye wastewater showed that the granules have great potentials in treating wastewater with different complexity. The removal efficiency of COD and TOC was not restricted by loading concentrations.


Assuntos
Compostos Azo/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Aminas/metabolismo , Anaerobiose , Compostos Azo/análise , Bactérias Anaeróbias/metabolismo , Reatores Biológicos , Corantes/metabolismo , Esgotos/microbiologia , Águas Residuárias , Poluentes Químicos da Água/análise
12.
Bioresour Technol ; 300: 122702, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31918294

RESUMO

This study demonstrates the continuous biohythane production in a single-stage anaerobic digester using a biomass mixture of separately entrapped hydrogenic and methanogenic bacteria (H2- and CH4-producing bacteria, respectively). The entrapped hydrogenic/methanogenic bacteria biomass ratios of 1/4, 2/3, 3/2 and 4/1 were tested and shown to have a great effect on the single-stage biohythane production performance. At steady-states, the cultivations had biohythane production rates in the range of 381-480 mL/L-d, with H2 content in biohythane (HCH) varying from 1% to 75% (v/v) and chemical oxygen demand removal efficiencies (TCODre) of 57.6-81.9%. Biomass ratio 2/3 (weight ratio 1/1.5) resulted in peak biohythane production with H2 and CH4 production rates being 64.6 and 395 mL/L-d, respectively, HCH 15% and TCODre 74.4%. The novelty of this work is to show the potential of producing biohythane from an innovative single-stage dark fermentation system using entrapped hydrogenic and methanogenic bacteria.


Assuntos
Hidrogênio , Metano , Anaerobiose , Bactérias , Bactérias Anaeróbias , Reatores Biológicos , Fermentação
13.
Water Res ; 171: 115468, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31926373

RESUMO

Anaerobic ammonium oxidizing (anammox) bacteria can directly convert ammonium and nitrite to nitrogen gas anaerobically and were responsible for a substantial part of the fixed nitrogen loss and re-oxidation of nitrite to nitrate in freshwater and marine ecosystems. Although a wide variety of studies have been undertaken to investigate the abundance and biodiversity of anammox bacteria so far, ecological niche differentiation of anammox bacteria is still not fully understood. To assess their growth behavior and consequent population dynamics at a given environment, the Monod model is often used. Here, we summarize the Monod kinetic parameters such as the maximum specific growth rate (µmax) and the half-saturation constant for nitrite (KNO2-) and ammonium (KNH4+) of five known candidatus genera of anammox bacteria. We also discuss potential pivotal environmental factors and metabolic flexibility that influence the community compositions of anammox bacteria. Particularly biodiversity of the genus "Scalindua" might have been largely underestimated. Several anammox bacteria have been successfully enriched from various source of biomass. We reevaluate their enrichment methods and culture medium compositions to gain a clue of niche differentiation of anammox bacteria. Furthermore, we formulate the current issues that must be addressed. Overall this review re-emphasizes the importance of enrichment cultures (preferably pure cultures), physiological characterization and direct microbial competition studies using enrichment cultures in laboratories.


Assuntos
Compostos de Amônio , Ecossistema , Anaerobiose , Bactérias , Bactérias Anaeróbias , Biodiversidade , Nitritos , Oxirredução , Compostos de Amônio Quaternário , RNA Ribossômico 16S
14.
PLoS One ; 15(1): e0227006, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31978071

RESUMO

Diabetic foot ulcers (DFUs) lead to nearly 100,000 lower limb amputations annually in the United States. DFUs are colonized by complex microbial communities, and infection is one of the most common reasons for diabetes-related hospitalizations and amputations. In this study, we examined how DFU microbiomes respond to initial sharp debridement and offloading and how the initial composition associates with 4 week healing outcomes. We employed 16S rRNA next generation sequencing to perform microbial profiling on 50 samples collected from 10 patients with vascularized neuropathic DFUs. Debrided wound samples were obtained at initial visit and after one week from two DFU locations, wound bed and wound edge. Samples of the foot skin outside of the wounds were also collected for comparison. We showed that DFU wound beds are colonized by a greater number of distinct bacterial phylotypes compared to the wound edge or skin outside the wound. However, no significant microbiome diversity changes occurred at the wound sites after one week of standard care. Finally, increased initial abundance of Gram-positive anaerobic cocci (GPAC), especially Peptoniphilus (p < 0.05; n = 5 subjects), was associated with impaired healing; thus, GPAC's abundance could be a predictor of the wound-healing outcome.


Assuntos
Desbridamento/métodos , Pé Diabético/complicações , Úlcera do Pé/microbiologia , Cocos Gram-Positivos/isolamento & purificação , Microbiota , Cicatrização , Idoso , Bactérias Anaeróbias , Pé Diabético/microbiologia , Feminino , Infecções por Bactérias Gram-Positivas , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Resultado do Tratamento
16.
Can J Microbiol ; 66(4): 288-302, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31986063

RESUMO

Characterization of the microbiota of chickens is of current interest. The goals of the current study were to apply anaerobic isolation methods to comprehensively isolate and identify bacteria from the gastrointestinal tract of chickens and their environment. Bacterial communities within the drinking water were dominated by Escherichia, whereas communities in litter were more representative of the cecum. The crop and small intestine (jejunum and ileum) were dominated by Lactobacillus and Enterococcus spp., and the cecum was dominated by Proteus spp. The collection of bacteria isolated was dominated by Enterococcus spp., Escherichia/Shigella spp., Lactobacillus spp., and Proteus spp.; however, many rare taxa were observed. These included members of the Clostridiales and Clostridium spp., which were commonly isolated from the ileum and cecum. Bacteria isolated by enrichment and direct plating differed. The selective de Man-Rogosa-Sharpe agar was commonly associated with the isolation of Lactobacillus spp. and yielded the lowest diversity of all methods utilized. Increased diversity and frequency of Clostridium spp. was observed in enrichments of blood and mucus or by plating on Columbia agar supplemented with 10% blood and gentamicin. The bacteria isolated from this study provide source material for genomic and functional studies in chicken hosts.


Assuntos
Bactérias Anaeróbias/isolamento & purificação , Galinhas/microbiologia , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Ceco/microbiologia , Íleo/microbiologia , Filogenia
17.
Appl Biochem Biotechnol ; 190(1): 232-251, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31332677

RESUMO

The genera Dysgonomonas, Coprococcus, Sporomusa, Bacteroides, Sedimentibacter, Pseudomonas, Ruminococcus, and Clostridium predominate in compost residue, and vadimCA02, Anaerobaculum, Tatlockia, Caloramator, and Syntrophus prevail in soil used as inoculum in batch rectors. This mixed consortium was used as inoculum for biogas production using different concentrations of sugarcane bagasse (SCB) (from 1.58 to 4.42 g/L) and yeast extract (YE) (from 0.58 to 3.42 g/L) according to a composite central design. The maximum ethanol production (20.11 mg L-1) was observed using 2.0 and 3.0 g L-1 of YE and SCB, respectively (C6). Likewise, the highest hydrogen production (0.60 mmol L-1) was observed using 3.0 and 4.0 g L-1 of YE and SCB, respectively (C1). Methane was also observed, reaching the maximum production (1.44 mmol L-1) using 1.0 and 4.0 g L-1 of YE and SCB, respectively (C2). The archaeal similarity between these conditions was above 90%; however, the richness and diversity were higher in the C2 (12 and 2.42, respectively) than in C1 (5 and 1.43, respectively) and C6 (11 and 2.29, respectively). Equally, the bacterial similarity between C1 and C6 was 60% while richness of 24 and 17 and diversity of 3.13 and 2.81 were observed in C1 and C6, respectively.


Assuntos
Bactérias Anaeróbias/metabolismo , Biocombustíveis , Bioprospecção , Saccharum/metabolismo , Anaerobiose , Fermentação
18.
Bioresour Technol ; 297: 122520, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31812597

RESUMO

This work aimed to evaluate the potential of anaerobic carboxylic acids (CA) production from swine wastewater (SW), perform modeling studies of the acidogenic process and estimate the kinetic parameters. Tests were carried out in four batch reactors with 250 mL reaction volume, with brewery sludge as inoculum and using chloroform (0.05%, v/v) for methanogenesis inhibition. Hydrolysis was the main limiting step of CA production from SW, once that it took more than twenty days for the particulate COD consumption to stabilize and fourteen days to produce 60% of the acids formed. A yield of 0.33 mg mgCODA-1, corresponding to 0.40 mgCOD mgCODA-1, was obtained. Kinetic models describing logistic growth functions were best suited to simulate CA production.


Assuntos
Reatores Biológicos , Águas Residuárias , Anaerobiose , Animais , Bactérias Anaeróbias , Ácidos Carboxílicos , Esgotos , Suínos , Eliminação de Resíduos Líquidos
19.
Am J Obstet Gynecol ; 222(2): 157.e1-157.e13, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31404542

RESUMO

BACKGROUND: Metronidazole is the first-line treatment for bacterial vaginosis, but cure rates are suboptimal and recurrence rates high. OBJECTIVES: To evaluate the impact of a standard course of oral metronidazole treatment (500 mg twice per day for 7 days) on the vaginal microbiota of Rwandan bacterial vaginosis patients using microscopy and 16S rRNA gene sequencing, and to evaluate correlates of treatment failure. STUDY DESIGN: HIV-negative, nonpregnant women aged 18-45 years with bacterial vaginosis and/or Trichomonas vaginalis (N=68) were interviewed and sampled before and after metronidazole treatment. They were also screened, and treated if applicable, for other urogenital infections. The vaginal microbiota was assessed by Gram stain Nugent scoring, Illumina 16S rRNA HiSeq sequencing (relative abundances), and BactQuant 16S gene quantitative polymerase chain reaction (estimated concentrations). Only women with a pretreatment Nugent score of 7-10 and a valid posttreatment Nugent score (N=55) were included in metronidazole treatment failure analyses, with treatment failure defined as a posttreatment Nugent score of 4-10. RESULTS: The bacterial vaginosis cure rate by Nugent scoring was 54.5%. The mean total vaginal bacterial concentration declined from 6.59 to 5.85 log10/µL (P<.001), which was mostly due to a reduction in mean bacterial vaginosis-associated anaerobes concentration (all bacterial vaginosis-associated anaerobe taxa combined) from 6.23 to 4.55 log10/µL (P<.001). However, only 16.4% of women had a bacterial vaginosis anaerobes concentration reduction of more than 50%, and only 3 women had complete eradication. The mean concentration of lactobacilli (all species combined) increased from 4.98 to 5.56 log10/µL (P=.017), with L. iners being the most common species pre- and posttreatment. The mean concentration of pathobionts (defined as Proteobacteria, streptococci, staphylococci, enterococci, and a few others) did not change significantly: from 1.92 log10/µL pretreatment to 2.01 log10/µL posttreatment (P=.939). Pretreatment pathobionts concentration, and having a pretreatment vaginal microbiota type containing more than 50% Gardnerella vaginalis (compared with less than 50%), were associated with increased likelihood of treatment failure, but the latter did not reach statistical significance (P=.044 and P=.084, respectively). CONCLUSIONS: Metronidazole alone may not cure women with high G. vaginalis relative abundance, potentially due to biofilm presence, and women with high pathobionts concentration. These women may benefit from additional biofilm-disrupting and/or pathobiont-targeting treatments.


Assuntos
Anti-Infecciosos/uso terapêutico , Metronidazol/uso terapêutico , Vaginite por Trichomonas/tratamento farmacológico , Vaginose Bacteriana/tratamento farmacológico , Adulto , Bactérias Anaeróbias , Biofilmes , Enterococcus , Feminino , Gardnerella vaginalis , Humanos , Lactobacillus , Proteobactérias , RNA Ribossômico 16S/genética , Ruanda , Staphylococcus , Streptococcus , Falha de Tratamento , Resultado do Tratamento , Vaginite por Trichomonas/complicações , Vaginite por Trichomonas/microbiologia , Vaginose Bacteriana/complicações , Vaginose Bacteriana/microbiologia , Adulto Jovem
20.
J Environ Manage ; 255: 109842, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31759203

RESUMO

The development of anaerobic digestion (AD) for volatile fatty acids (VFAs) production from waste activated sludge (WAS) is arrested due to low hydrolysis and acidification efficiency. This study proposed to enhance WAS reduction and VFAs accumulation during AD process via bioaugmentation of acetate-producing bacteria. Four acetogens were firstly isolated from a temperature-phased anaerobic digestion (TPAD) system. The acetate production efficiency of different isolates ranged from 15.8 to 73.7 mg acetate/g TOC, in which the bacterial strain NJUST19 was found to be the most effective strain. The results of morphological, biochemical characteristics as well as phylogenetic analysis showed that the isolate NJUST19 was Gram-positive and rod-shaped, catalase-negative, nitrate reduction-positive, methyl red-negative and capable of starch and gelatin hydrolysis, for which the name of Clostridium sp. NJUST19 was proposed. The optimal culture conditions (i.e. initial pH and temperature) were evaluated for their effects on microbe growth of selected NJUST19, and the maximum acetate production was observed at pH 9.0 and temperature of 40 °C. In the case of modified TPAD system inoculated with Clostridium sp. NJUST19, total suspended solids (TSS) removal rate and maximum VFAs accumulation increasing to 35.3% and 4200 mg/L, respectively, which was much higher than that of control (21.9% and 2894 mg/L). These results indicated that Clostridium sp. NJUST 19 is capable of enhancing digestion efficiency with a great benefit for VFAs production, offering potential prospects for bioaugmentation of WAS anaerobic digestion.


Assuntos
Ácidos Graxos Voláteis , Esgotos , Anaerobiose , Bactérias , Bactérias Anaeróbias , Reatores Biológicos , Filogenia
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