52 research outputs found

    Anaerobic Digestion for Simultaneous Sewage Sludge Treatment and CO Biomethanation: Process Performance and Microbial Ecology

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    Syngas is produced by thermal gasification of both nonrenewable and renewable sources including biomass and coal, and it consists mainly of CO, CO<sub>2</sub>, and H<sub>2</sub>. In this paper we aim to bioconvert CO in the syngas to CH<sub>4</sub>. A novel technology for simultaneous sewage sludge treatment and CO biomethanation in an anaerobic reactor was presented. Batch experiments showed that CO was inhibitory to methanogens, but not to bacteria, at CO partial pressure between 0.25 and 1 atm under thermophilic conditions. During anaerobic digestion of sewage sludge supplemented with CO added through a hollow fiber membrane (HFM) module in continuous thermophilic reactors, CO did not inhibit the process even at a pressure as high as 1.58 atm inside the HFM, due to the low dissolved CO concentration in the liquid. Complete consumption of CO was achieved with CO gas retention time of 0.2 d. Results from high-throughput sequencing analysis showed clear differences of the microbial community structures between the samples from liquid and biofilm on the HFM in the reactor with CO addition. Species close to <i>Methanosarcina barkeri</i> and <i>Methanothermobacter thermautotrophicus</i> were the two main archaeal species involved in CO biomethanation. However, the two species were distributed differently in the liquid phase and in the biofilm. Although the carboxidotrophic activities test showed that CO was converted by both archaea and bacteria, the bacterial species responsible for CO conversion are unknown

    Non-proportional aerodynamic damping of transmission line conductors under wind loads

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    This paper was reviewed and accepted by the APCWE-IX Programme Committee for Presentation at the 9th Asia-Pacific Conference on Wind Engineering, University of Auckland, Auckland, New Zealand, held from 3-7 December 2017

    Antibiotic Resistance Genes and Correlations with Microbial Community and Metal Resistance Genes in Full-Scale Biogas Reactors As Revealed by Metagenomic Analysis

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    Digested residues from biogas plants are often used as biofertilizers for agricultural crops cultivation. The antibiotic resistance genes (ARGs) in digested residues pose a high risk to public health due to their potential spread to the disease-causing microorganisms and thus reduce the susceptibility of disease-causing microorganisms to antibiotics in medical treatment. A high-throughput sequencing (HTS)-based metagenomic approach was used in the present study to investigate the variations of ARGs in full-scale biogas reactors and the correlations of ARGs with microbial communities and metal resistance genes (MRGs). The total abundance of ARGs in all the samples varied from 7 × 10<sup>–3</sup> to 1.08 × 10<sup>–1</sup> copy of ARG/copy of 16S-rRNA gene, and the samples obtained from thermophilic biogas reactors had a lower total abundance of ARGs, indicating the superiority of thermophilic anaerobic digestion for ARGs removal. ARGs in all the samples were composed of 175 ARG subtypes; however, only 7 ARG subtypes were shared by all the samples. Principal component analysis and canonical correspondence analysis clustered the samples into three groups (samples from manure-based mesophilic reactors, manure-based thermophilic reactors, and sludge-based mesophilic reactors), and substrate, temperature, and hydraulic retention time (HRT) as well as volatile fatty acids (VFAs) were identified as crucial environmental variables affecting the ARGs compositions. Procrustes analysis revealed microbial community composition was the determinant of ARGs composition in biogas reactors, and there was also a significant correlation between ARGs composition and MRGs composition. Network analysis further revealed the co-occurrence of ARGs with specific microorganisms and MRGs

    Participants with driving experience accurately estimated speed for wide and narrow roads whereas participants without driving experience underestimated speed with greater underestimation on wide roads.

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    <p>Participants with driving experience accurately estimated speed for wide and narrow roads whereas participants without driving experience underestimated speed with greater underestimation on wide roads.</p

    MOESM1 of Methane potentials of wastewater generated from hydrothermal liquefaction of rice straw: focusing on the wastewater characteristics and microbial community compositions

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    Additional file 1: Table S1. Characteristics of rice straw and the following line is standard error of each value; Table S2. Number of the high-quality sequences; Figure S1. COD, TOC and pH values of HTLWW samples under different HTL conditions; Figure S2. Comparison of methane production potentials of samples 200 °C–0.5 h, 260 °C–0.5 h and 200 °C–4 h

    Interface for driving speed estimation system showing examples of the narrow and wide road types and 4 image scales (upper left-scale 1.0, upper right-scale 0.75, lower left-scale 0.5, lower right-scale 0.38).

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    <p>Interface for driving speed estimation system showing examples of the narrow and wide road types and 4 image scales (upper left-scale 1.0, upper right-scale 0.75, lower left-scale 0.5, lower right-scale 0.38).</p

    Data_Sheet_1_Enhancement of HSA-pFSHβ production by disrupting YPS1 and supplementing N-acetyl-L-cysteine in Pichia pastoris.docx

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    IntroductionPichia pastoris is widely used for the production of recombinant proteins, but the low production efficiency hinders its wide application in biopharmaceuticals. Moreover, many biopharmaceutical-like proteins are accompanied by degradation during secretory expression in P. pastoris.ObjectiveIn this study, we used human serum albumin and porcine follicle-stimulating hormone β (HSA-pFSHβ) fusion protein as a model protein to investigate whether YPS1 and YPT7 gene disruption and N-acetyl-L-cysteine (NAC) supplementation have synergistic effects to inhibit the degradation of recombinant proteins.Results and discussionOur results showed that YPS1 gene disruption reduced the degradation of intact HSA-pFSHβ and increased the yield of intact protein in the culture medium and cells without affecting the integrity of the cell wall. Moreover, the beneficial effects of YPS1 gene disruption were associated with the upregulation of the MAPK signaling pathway and maintenance of redox homeostasis. YPS1 gene disruption and NAC supplementation had synergistic effects on HSA-pFSHβ production. In addition, disruption of vacuolar morphology by YPT7 gene disruption or NH4Cl treatment affected the production of recombinant HSA-pFSHβ protein. Furthermore, YPT7 gene disruption inhibited the processing of signal peptide in high-level produced HSA-pFSHβ strain. In conclusion, our results demonstrated that YPS1 disruption could reduce the degradation of intact HSA-pFSHβ proteins, and synergistically increase the yield of intact HSA-pFSHβ with NAC supplementation. This study provided a valuable reference for reducing recombinant protein degradation and therefore improving the yield of recombinant proteins in P. pastoris.</p
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