Zobrazení zdroje stránky Willumsencarson2219

To investigate the role of electroactive biofilms for enhanced phenolic degradation, lignite activated coke (LAC) and MAC were used as carriers in moving-bed biofilm reactor (MBBR) for CPW treatment. In contrast to activated sludge (AS) reactor, the carriers improved degradation performance of MBBR. Although two MBBRs exerted similar degradation capacity with over 92% of COD and 93% phenols removal under the highest phenolics concentration (500 mg/L), the effluent of MAC-based MBBR remained higher biodegradability (BOD5/COD = 0.34 vs 0.18) than that of LAC-based MBBR. Metagenomic analysis revealed that electroactive biofilms determined phenolic degradation of MAC-based MBBR. Primarily, Geobacter (17.33%) started Fe redox cycle on biofilms and developed syntrophy with Syntrophorhabdus (6.47%), which fermented phenols into easily biodegradable substrates. Subsequently, Ignavibacterium (3.38% to 2.52%) and Acidovorax (0.46% to 8.83%) conducted biological electricity from electroactive biofilms to suspended sludge. They synergized with dominated genus in suspended sludge, Alicycliphilus (19.56%) that accounted for phenolic oxidation and nitrate reduction. Consequently, the significantly advantage of Geobater and Syntrophorhabdus was the keystone reason for superior biodegradability maintenance of MAC-based MBBR. The influence of silicate on the structural memory effect of layered double hydroxides (LDHs) has been rarely reported. In this study, five kinds of calcined LDHs (CLDHs) were synthesized and used as adsorbents for the sorption of selenium with or without silicate, under the initial pH 10 and 13, respectively, characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectroscopy (IR), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and N2 adsorption-desorption isotherm. The results indicated that silicate can significantly affect the phase transformation of CLDHs, and the sorption amounts of selenite and selenate dramatically decreased in the presence of silicate. Specifically, silicate can react with MgO and Al2O3 in CLDHs to generate magnesium silicate hydrate and geopolymer-like substance which were covered on the surface of particles, blocking the hydroxylation of metal oxides. However, higher pH suppressed the interaction between MgO and silicate and enhanced the formation of geopolymer-like substance, which promoted the regeneration of LDHs. Al in CLDHs plays a critical role in the regeneration of LDHs. Besides, the ternary oxides (CLDH-2, Mg2Al0.75Fe0.25-oxide; CLDH-3, Mg2Al0.5Fe0.5-oxide) possessed larger specific surface areas (127.7 and 158.2 m2/g) and consequently presented more resistance to the effect of silicate. Coronavirus disease 2019 (COVID-19) caused by the previously unknown pathogen, severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) is now a global pandemic. There are no vaccines or specific treatments against this new virus; therefore, there is an urgent need to advance novel therapeutic interventions for COVID-19. Glycyrrhizin is a triterpene saponin with various biological functions and pharmacological effects. This brief article discusses the therapeutic potential of glycyrrhizin for the treatment of COVID-19 from the perspective of its pharmacological action, including binding angiotensin-converting enzyme II (ACE2), downregulating proinflammatory cytokines, inhibiting the accumulation of intracellular reactive oxygen species (ROS), inhibiting thrombin, inhibiting the hyperproduction of airway exudates, and inducing endogenous interferon. OBJECTIVES This study aimed at identifying and characterizing oxazolidinone resistance genes cfr and optrA in Enterococcus isolates. METHODS We screened 293 Enterococcus isolates for the presence of cfr and optrA genes by PCR. The transferability of cfr and optrA was examined by conjugation. S1 nuclease PFGE and Southern blotting were used to identify the location of cfr and optrA. One Enterococcus faecalis isolate carrying both cfr and optrA genes was completely sequenced. RESULTS The cfr and optrA genes were detected in 16 (5.5%) and 170 (58.0%) Enterococcus isolates, respectively. Sixteen Enterococcus isolates (E. faecalis n=13; Enterococcus avium n=2; Enterococcus mundtii n=1) carried both cfr and optrA genes. The cfr-carrying fragment between res and theta in plasmid p4 showed 98.9% identity to the corresponding region of plasmid pEF120805 from vancomycin-resistant Enterococcus faecium. The optrA-carrying segment between tnpB and optrA in plasmid p1 showed &gt;99.9% identity to the corresponding region of genomic DNA from E. faecalis A101. Plasmid p4 and plasmid p1 were simultaneously conjugated to E. faecalis JH2-2. [https://www.selleckchem.com/products/cvt-313.html selleck chemical] CONCLUSIONS It was worth noting that 170 optrA-positive enterococci were identified in 293 Enterococcus isolates from swine and farm environment. The co-existence of cfr and optrA genes in E. avium and E. mundtii was first identified. The cfr and optrA genes were identified on two new conjugative plasmids from one E. faecalis isolate. The optrA-carrying segment (IS1216E-optrA-IS1216E) was first reported. Among different types of enterococcal plasmids, ISEnfa5 and IS1216E elements may play a vital role in the dissemination of cfr and optrA, respectively. V.β-lactamases are the major resistance determinant for β-lactam antibiotics in Gram-negative bacteria. Although there are β-lactamase inhibitors (BLIs) available, β-lactam-BLI combinations are increasingly being neutralized by diverse mechanisms of bacterial resistance. We hypothesized that permeability-increasing antimicrobial peptides (AMPs) could lower the amount of BLIs necessary to sensitize bacteria to antibiotics that are β-lactamase substrates. To test this hypothesis, we performed checkerboard assays and measured the ability of several AMPs, to synergize with piperacillin, ticarcillin, amoxicillin, ampicillin and ceftazidime in the presence of either, tazobactam, clavulanic acid, sulbactam, aztreonam, phenylboronic acid (PBA) or oxacillin. Assays were performed using planktonic and biofilm-forming cells of Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae overexpressing β-lactamases. Synergy between polymyxin B nonapeptide (PMBN) and tazobactam boosted piperacillin activity by a factor of 128 in E.