253 research outputs found

    Syntroph Diversity and Abundance in Anaerobic Digestion Revealed Through a Comparative Core Microbiome Approach

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    Anaerobic digestion is an important biotechnology treatment process for conversion of waste to energy. In this study, a comparative core microbiome approach, i.e., determining taxa that are shared in functioning digesters but not shared in non-functioning digesters, was used to determine microbial taxa that could play key roles for effective anaerobic digestion. Anaerobic digester functions were impaired by adding the broad-spectrum antimicrobial triclosan (TCS) or triclocarban (TCC) at different concentrations, and the core microbiomes in both functioning and non-functioning anaerobic digesters were compared. Digesters treated with high (2500 mg/kg) or medium (450 mg/kg) TCS and high (850 mg/kg) TCC concentrations lost their function, i.e., methane production decreased, effluent volatile fatty acid concentrations increased, and pH decreased. Changes in microbial community diversity and compositions were assessed using 16S rRNA gene amplicon sequencing. Microbial richness decreased significantly in non-functioning digesters (p \u3c 0.001). Microbial community compositions in non-functioning digesters significantly differed from those in functioning digesters (p = 0.001, ANOSIM). Microbes identified as potentially key taxa included previously known fatty acid-degrading syntrophs and amino acid-degrading syntrophs. A diverse group of syntrophs detected in this study had low relative abundance in functioning digesters, suggesting the importance of rare microbes in anaerobic digester operation. The comparative microbiome approach used in this study can be applied to other microbial systems where a community-driven biological phenomena can be observed directly

    Effect of Nonmagnetic Impurity in Nearly Antiferromagnetic Fermi Liquid: Magnetic Correlations and Transport Phenomena

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    In nearly antiferromagnetic (AF) metals such as high-Tc superconductors (HTSC's), a single nonmagnetic impurity frequently causes nontrivial widespread change of the electronic states. To elucidate this long-standing issue, we study a Hubbard model with a strong onsite impurity potential based on an improved fluctuation-exchange (FLEX) approximation, which we call the GV^I-FLEX method. This model corresponds to the HTSC with dilute nonmagnetic impurity concentration. We find that (i) both local and staggered susceptibilities are strongly enhanced around the impurity. By this reason, (ii) the quasiparticle lifetime as well as the local density of states (DOS) are strongly suppressed in a wide area around the impurity (like a Swiss cheese hole), which causes the ``huge residual resistivity'' beyond the s-wave unitary scattering limit. We stress that the excess quasiparticle damping rate caused by impurities has strong momentum-dependence due to non-s-wave scatterings induced by many-body effects, so the structure of the ``hot spot/cold spot'' in the host system persists against impurity doping. This result could be examined by the ARPES measurements. In addition, (iii) only a few percent of impurities can causes a ``Kondo-like'' upturn of resistivity (dρ/dT<0d\rho/dT<0) at low temperatures when the system is very close to the AF quantum critical point (QCP). The results (i)-(iii) obtained in the present study, which cannot be derived by the simple FLEX approximation, naturally explains the main impurity effects in HTSC's. We also discuss the impurity effect in heavy fermion systems and organic superconductors.Comment: 22 pages, to be published in PR

    Removal of Antibiotic Resistance Genes in an Anaerobic Membrane Bioreactor Treating Primary Clarifier Effluent at 20 °C

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    Anaerobic membrane bioreactors (AnMBR) play a key role in future plans for sustainable wastewater treatment and resource recovery because they have no energy-intensive oxygen transfer requirements and can produce biomethane for renewable energy. Recent research results show that they can meet relatively stringent discharge limits with respect to BOD5 and TSS when treating municipal wastewater primary effluent. Sustainable used water recovery plans should also consider removal of unregulated pollutants. Antibiotic resistance genes (ARGs) represent an important emerging contaminant due to public health concerns surrounding the spread of infections resistant to common antibiotics. Conventional activated sludge processes have demonstrated mixed results regarding ARG removal. The objective of this research was to determine the impact of an AnMBR on ARG removal when treating municipal primary clarifier effluent at 20 °C. AnMBR treatment resulted in 3.3 to 3.6 log reduction of ARG and the horizontal gene transfer determinate, intI1, copies in filtrate. Membrane treatment significantly decreased the total biomass as indicated by a decrease in 16S rRNA gene concentration. Microbial community analysis via Illumina sequencing revealed that the relative abundance of putative pathogens was higher in membrane filtrate compared to primary effluent although the overall bacterial 16S rRNA gene concentrations was lower in filtrate. Membrane treatment also substantially reduced microbial diversity in filtrate compared to anaerobic reactor contents

    CpG oligodeoxynucleotides induce strong up-regulation of interleukin 33 via Toll-like receptor 9

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    We previously reported the strong immunostimulatory effects of a CpG oligodeoxynucleotide (ODN), designated MsST, from the lacZ gene of Streptococcus (S.) thermophilus ATCC19258. Here we show that 24 h of stimulation with MsST in mouse splenocytes and peritoneal macrophages strongly induces expression of interleukin (IL)-33, a cytokine in the IL-1 superfamily. Other IL-1 superfamily members, including IL-1 alpha, IL-1 beta and IL-18, are down-regulated after 24 h of stimulation of MsST. We also found that MsST-induced IL-33 mRNA expression is inhibited by the suppressive ODN A151, which can inhibit Toll-like receptor 9 (TLR9)-mediated responses. This is the first report to show that IL-33 can be induced by CpG ODNs. The strong induction of IL-33 by MsST suggests that it may be a potential therapeutic ODN for the treatment of inflammatory disease. The presence of a strong CpG ODN in S. thermophilus also suggests that the bacterium may be a good candidate as a starter culture for the development of new physiologically functional foods.ArticleBIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS. 394(1):81-86 (2010)journal articl

    Associations between the distance covered in the incremental shuttle walk test and lung function and health status in patients with chronic obstructive pulmonary disease

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    Background: Field walk tests such as the incremental shuttle walk test (ISWT) are simple tests for assessing the degree of disability in individuals with chronic obstructive pulmonary disease (COPD). In the present study, the correlations between exercise performance in the ISWT, lung function, and health status were examined in patients with COPD of varying seventies. Methods: A retrospective examination of 277 COPD patients was performed using the ISWT and lung function tests along with assessment of health status using St. George's Respiratory Questionnaire (SGRQ). In addition, we assessed the correlations between the walking distance, lung function parameters, and SGRQ scores. Results: ISWT distances were poorly correlated with lung function parameters and SGRQ scores in mild COPD patients. In contrast, ISWT distances were significantly correlated with pulmonary function parameters, such as vital capacity (%predicted) and forced expiratory volume in one second, and SGRQ scores in moderate and severe COPD patients. Conclusions: The ISWT is more independent of health status and pulmonary function in patients with mild COPD compared to moderate or severe cases. Therefore, the exercise capacity of patients with mild COPD should be estimated by the ISWT. (C) 2016 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.ArticleRESPIRATORY INVESTIGATION.55(1):33-38(2017)journal articl
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