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1.
Bioresour Technol ; 329: 124913, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33711716

RESUMEN

This study investigated the tolerance, defensive response and methanogenic pathways of anaerobic granular slugde and anaerobic suspended sludge (AGS and ASS) exposed to different LCM concentrations. AGS presented a higher tolerance to LCM stress, accompanied with 20.8 ± 2.6% enhancement in methane production at 1000 mg/L LCM, which was likely attributed to the less cell deaths and extracellular polymeric substances (EPSs) protection. In the acidification stage, acetate accumulation was stimulated and the activity of acetate kinase was promoted by LCM. In the methanogenesis stage, propionate and butyrate utilization for methane production were impaired after LCM addition. LCM also improved the activity of pyruvate-ferredoxin oxidoreductase and strengthened the process of hydrogenotrophic methanogenesis, likely by accelerating interspecies electron transfer mediated by hydrogen. ErmB and ermF were the dominate LCM resistance genes in AGS under LCM pressure conferring the resistance mechanism of ribosomal protection.


Asunto(s)
Biocombustibles , Aguas del Alcantarillado , Anaerobiosis , Reactores Biológicos , Lincomicina , Metano
2.
Microorganisms ; 8(5)2020 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-32455626

RESUMEN

In this study, hydrogenotrophic methanogenic mixed cultures taken from 13 lab-scale ex-situ biogas upgrading systems under different temperature (20-70 °C), pH (6.0-8.5), and CO (0-10%, v/v) variables were systematically investigated. High-throughput 16S rRNA gene sequencing was used to identify the microbial consortia, and statistical analyses were conducted to reveal the microbial diversity, the core functional microbes, and their correlative relationships with tested variables. Overall, bacterial community was more complex than the archaea community in all mixed cultures. Hydrogenotrophic methanogens Methanothermobacter, Methanobacterium, and Methanomassiliicoccus, and putative syntrophic acetate-oxidizing bacterium Coprothermobacter and Caldanaerobacter were found to predominate, but the core functional microbes varied under different conditions. Multivariable sensitivity analysis indicated that temperature (p < 0.01) was the crucial variable to determine the microbial consortium structures in hydrogenotrophic methanogenic mixed cultures. pH (0.01 < p < 0.05) significantly interfered with the relative abundance of dominant archaea. Although CO did not affect community (p > 0.1), some potential CO-utilizing syntrophic metabolisms might be enhanced. Understanding of microbial consortia in the hydrogenotrophic methanogenic mixed cultures related to environmental variables was a great advance to reveal the microbial ecology in microbial biogas upgrading process.

3.
Naunyn Schmiedebergs Arch Pharmacol ; 393(11): 2221-2229, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32076762

RESUMEN

Schisandrin A (Sch A) is a lignin extracted from the fruit of Schisandra chinensis, which has potential anti-inflammatory properties and is used for treating various inflammatory diseases. In this study, we aimed to evaluate the anti-inflammatory effects of Sch A and the underlying mechanisms in animal models of acute inflammation. First, the anti-inflammatory effects of Sch A were evaluated preliminarily in an animal model of xylene-induced ear edema. Sch A pretreatment significantly decreased the degree of edema and inhibited telangiectasia in the ear. Second, a mouse model of paw edema was used to investigate the anti-inflammatory effects and mechanisms of Sch A. Pretreatment with Sch A significantly inhibited carrageenan-induced paw edema in mice. Hematoxylin-eosin (HE) staining of paw tissues demonstrated that Sch A inhibited the infiltration of inflammatory cells in the mouse model of paw edema. Enzyme-linked immunosorbent assay (ELISA) results indicated that the levels of inflammatory factors decreased. The western blot and immunohistochemical assay results revealed that the toll-like receptor 4/nuclear factor kappa-B (TLR4/NF-κB) pathway could play a role in the anti-inflammatory functions of Sch A. The findings demonstrated that Sch A exerts anti-inflammatory effects and may provide possible strategies for the treatment of inflammatory diseases.

4.
Bioresour Technol ; 299: 122565, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31865150

RESUMEN

The potential for microbial protein production in the mixture of yellow wine lees and rice soaking wastewater was examined. Strong symbiotic effect was observed in fermentation with yeast-fungus mixed culture of Candida utilis and Geochichum candidum at a ratio of 1:1 (v/v). The maximum specific biomass yield of 4.91 ± 0.48 g final biomass/g initial biomass with a protein content of 68.5 ± 1.0% was achieved at inoculum-to-substrate ratio of 10% (v/v) and aeration rate of 1.0 volumeair/volumeliquid/min. The essential amino acids contents of the derived protein were comparable to commercial protein sources with high amounts of methionine (2.87%, based on total protein). The reduction in soluble chemical oxygen demand of 79.4 ± 0.4% was mainly due to uptake of carbohydrate, soluble protein, volatile fatty acids, amino acids, etc. The application of mixed yeast-fungus technology provides a new opportunity for microbial protein production from these low-value organic residue streams.


Asunto(s)
Vino , Análisis de la Demanda Biológica de Oxígeno , Biomasa , Fermentación , Saccharomyces cerevisiae
5.
Bioresour Technol ; 257: 157-163, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29499497

RESUMEN

A complex of water-hyacinth derived pellets immobilized with Chlorella sp. was applied, for the first time, in the bioremediation of Cadmium (Cd). The Cd(II) removal efficiency of the complex was optimized by investigating several parameters, including the pellet materials, algal culture age, and light intensity. Results showed that the Cd(II) removal efficiency was positively related to the algal immobilization efficiency and the algal bioaccumulation capacity. Since higher surface hydrophilicity leads to higher immobilization efficiency, the water-hyacinth leaf biochar pellet (WLBp) was selected as the optimal carrier. A maximum Cd(II) removal efficiency of 92.45% was obtained by the complex of WLBp immobilized with algal cells in stationary growth phase and illuminated with a light intensity of 119 µmol m-2 s-1. Recovery tests on both microalgal cells and the WLBp demonstrated that the algal cells and the biochar pellet can be economically recycled and reused.


Asunto(s)
Biodegradación Ambiental , Cadmio , Eichhornia , Adsorción , Chlorella , Hyacinthus
6.
Bioresour Technol ; 244(Pt 1): 1031-1038, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28847109

RESUMEN

The feasibility of the bioremediation of cadmium (Cd) using microalgal-biochar immobilized complex (MBIC) was investigated. Major operating parameters (e.g., pH, biosorbent dosage, initial Cd(II) concentration and microalgal-biochar ratio) were varied to compare the treatability of viable algae (Chlorella sp.), biochar and MBIC. The biosorption isotherms obtained by using algae or biochar were found to have satisfactory Langmuir predictions, while the best fitting adsorption isotherm model for MBIC was the Sips model. The maximum Cd(II) adsorption capacity of MBIC with a Chlorella sp.: biochar ratio of 2:3 (217.41mgg-1) was higher than that of Chlorella sp. (169.92mgg-1) or biochar (95.82mgg-1) alone. The pseudo-second-order model fitted the biosorption process of MBIC well (R2>0.999). Moreover, zeta potential, SEM and FTIR studies revealed that electrostatic attraction, ion exchange and surface complexation were the main mechanisms responsible for Cd removal when using MBIC.


Asunto(s)
Cadmio , Carbón Orgánico , Microalgas , Purificación del Agua , Adsorción , Chlorella , Concentración de Iones de Hidrógeno
7.
J Biosci Bioeng ; 121(4): 424-30, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26553477

RESUMEN

The objective of this study was to investigate the effects of culture conditions, including carbon sources and concentration, culture period, and precondition time, on the production of extracellular polymeric substances (EPS) and its influence on microalgal flocculation. EPS are natural high molecule polymer, excreted by microalgae themselves. EPS can accelerate the formation of microbial aggregates through binding cells closely. Organic carbon sources, such as glucose, glycerol, acetate and glycine were compared to select the optimal source to stimulate EPS accumulation. Subsequently, the effect of culture period, glycine dose and precondition time on EPS production and its influence on biomass growth and flocculation efficiency were investigated. As the main parts of EPS, tightly bound EPS were found positively related to suspended solids concentration. However, the loosely bound EPS may weaken the floc structure, leading to poor water-cells separation. Under the optimal condition with culture period of 16 days, glycine dose of 0.5 g l(-1) and precondition time of 5 days, the biomass concentration increased from 1.49 to 2 g l(-1), and the maximum suspended solids concentration of 7.06% with biomass recovery rate of 70.6% was achieved.


Asunto(s)
Técnicas de Cultivo de Célula , Chlorophyta/efectos de los fármacos , Chlorophyta/crecimiento & desarrollo , Glicina/metabolismo , Glicina/farmacología , Biomasa , Biopolímeros/biosíntesis , Biopolímeros/metabolismo , Carbono/metabolismo , Agregación Celular/efectos de los fármacos , Chlorophyta/metabolismo , Floculación , Microalgas/efectos de los fármacos , Microalgas/crecimiento & desarrollo , Microalgas/metabolismo , Factores de Tiempo
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