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1.
PLoS Pathog ; 19(4): e1011305, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37053288

RESUMEN

N6-methyladenosine (m6A) modification on viral RNAs has a profound impact on infectivity. m6A is also a highly pervasive modification for influenza viral RNAs. However, its role in virus mRNA splicing is largely unknown. Here, we identify the m6A reader protein YTHDC1 as a host factor that associates with influenza A virus NS1 protein and modulates viral mRNA splicing. YTHDC1 levels are enhanced by IAV infection. We demonstrate that YTHDC1 inhibits NS splicing by binding to an NS 3' splicing site and promotes IAV replication and pathogenicity in vitro and in vivo. Our results provide a mechanistic understanding of IAV-host interactions, a potential therapeutic target for blocking influenza virus infection, and a new avenue for the development of attenuated vaccines.


Asunto(s)
Virus de la Influenza A , Gripe Humana , Humanos , Virus de la Influenza A/genética , Virus de la Influenza A/metabolismo , Gripe Humana/genética , Replicación Viral/genética , ARN Mensajero/genética , Factores de Empalme de ARN/metabolismo , Proteínas del Tejido Nervioso/metabolismo
2.
J Virol ; 97(10): e0092623, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37754758

RESUMEN

IMPORTANCE: Type I interferon (IFN-I), produced by the innate immune system, plays an essential role in host antiviral responses. Proper regulation of IFN-I production is required for the host to balance immune responses and prevent superfluous inflammation. IFN regulatory factor 3 (IRF3) and subsequent sensors are activated by RNA virus infection to induce IFN-I production. Therefore, proper regulation of IRF3 serves as an important way to control innate immunity and viral replication. Here, we first identified Prohibitin1 (PHB1) as a negative regulator of host IFN-I innate immune responses. Mechanistically, PHB1 inhibited the nucleus import of IRF3 by impairing its binding with importin subunit alpha-1 and importin subunit alpha-5. Our study demonstrates the mechanism by which PHB1 facilitates the replication of multiple RNA viruses and provides insights into the negative regulation of host immune responses.


Asunto(s)
Proteína 58 DEAD Box , Prohibitinas , Virus ARN , Receptores Inmunológicos , Transducción de Señal , Replicación Viral , Proteína 58 DEAD Box/antagonistas & inhibidores , Proteína 58 DEAD Box/metabolismo , Inmunidad Innata , Factor 3 Regulador del Interferón/metabolismo , Carioferinas/metabolismo , Prohibitinas/metabolismo , Receptores Inmunológicos/antagonistas & inhibidores , Receptores Inmunológicos/metabolismo , Interferón Tipo I/biosíntesis , Interferón Tipo I/inmunología , Virus ARN/crecimiento & desarrollo , Virus ARN/inmunología , Virus ARN/metabolismo
3.
Microb Pathog ; : 106768, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38960217

RESUMEN

Fowl cholera is an infectious disease that affects both poultry and wild birds, characterized by hemorrhagic and septicemic symptoms, caused by Pasteurella multocida (P. multocida), and leading to substantial economic losses in the poultry sector. The development of genetic engineering vaccines against avian P. multocida encountered early-stage challenges due to the limited availability of effective gene editing tools. Presently, NgAgoDM-enhanced homologous recombination stands as a potent technique for achieving efficient gene knockout in avian P. multocida. Hence, this study employed NgAgoDM-enhanced homologous recombination to target and knockout hyaE (239-359aa), hyaD, hexABC, and hexD, denoted as ΔhyaE (239-359aa), ΔhyaD, ΔhexABC, and ΔhexD, respectively. Additionally, we generated a hyaD recovery strain with two point mutations, designated as mhyaD. Thus, this study systematically examined the impact of capsular synthetic gene clusters on the pathogenicity of P. multocida. Moreover, the study demonstrated the critical role of hyaD activity in the virulence of avian P. multocida. This study offers novel insights for enhancing attenuated vaccines further.

4.
Environ Res ; 241: 117602, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37951379

RESUMEN

Abyssal and hadal sediments represent two of the most type ecosystems on Earth and have the potential interactions with geochemistry. However, little is known about the prokaryotic community assembly and the response of prokaryotic communities to metal(loid)s in trench sediments due to the lack of adequate and appropriate samples. In this study, a systematic investigation combined the assembly mechanisms and co-occurrence patterns of prokaryotic communities between the hadal and abyssal sediments across the Yap Trench. The results revealed that the hadal prokaryotes had less species diversity, but more abundant function than the abyssal prokaryotes. The prokaryotic communities in the abyssal sediments had more core taxa than the hadal sediments. Twenty-one biomarkers mostly affiliated with Nitrosopumilaceae were detected using Random-Forests machine learning algorithm. Furthermore, stochasticity was dominant in the prokaryotic community assembly processes of the Yap Trench sediments. Meanwhile, homogeneous selection (32.6%-52.9%) belonging to deterministic processes governed the prokaryotic community assembly in hadal sediments with increasing of sediment depth. In addition to total nitrogen and total organic carbon, more metal(loid)s were significantly correlated with the prokaryotic community in the hadal sediments than that in the abyssal sediments. The hadal prokaryotic communities was most positively related to bismuth (r = 0.31, p < 0.01), followed by calcium, chromium, cerium, potassium, plumbum, scandium, titanium, and vanadium. Finally, co-occurrence networks revealed two potential dominant prokaryotic modules in Yap Trench sediments covaried across oceanographic zonation. By contrast, the hadal network had relatively more complexity, more bacterial taxa, and more associations among prokaryotic taxa, relative to the abyssal network. This study reveals potentially metal variables and community assembly mechanisms of the prokaryotic community in abyssal and hadal sediments and provides a better understanding on the prokaryotic diversity and ecology in trench sediment ecosystems.


Asunto(s)
Bacterias , Ecosistema , Archaea , Ecología , Cromo , Sedimentos Geológicos
5.
Antonie Van Leeuwenhoek ; 117(1): 44, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38413433

RESUMEN

Two fungal strains (K-2T and S1) were isolated from the deepest ocean sediment of the Challenger Deep located in the Mariana Trench. The internal transcribed spacer (ITS) gene sequences of the isolates K-2T and S1 differed from those of closely related species, such as Talaromyces assiutensis and T. trachyspermus. Phylogenetic analyses based on single and concatenated alignments of the genes, namely ITS, ß-tubulin (benA), calmodulin (cam), and the second-largest subunit fragment of the RNA polymerase II (rpb2) showed that the isolates K-2T and S1 were clustered together with other Talaromyces species, such as T. trachyspermus and T. assiutensis, as evidenced by the position on a terminal branch with high bootstrap support. They could also be distinguished from their closest relatives with valid published names via morphological and physiological characteristics, for example, growth at 4 °C-50 °C with a pH in the range of 1.5-12. Based on their phylogenetic, morphological, and physicochemical properties, the isolates K-2T and S1 represent a novel species in the genus Talaromyces, and the proposed name is Talaromyces sedimenticola sp. nov. The type strain is K-2T (= GDMCC 3.746T = JCM 39451T).


Asunto(s)
Ácidos Grasos , Talaromyces , Ácidos Grasos/química , Análisis de Secuencia de ADN , Filogenia , ARN Ribosómico 16S/genética , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética
6.
Ecotoxicol Environ Saf ; 280: 116588, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38878332

RESUMEN

Simultaneous heterotrophic nitrification and aerobic denitrification (SND) is gaining tremendous attention due to its high efficiency and low cost in water treatment. However, SND on an industrial scale is still immature since effects of coexisting pollutants, for example, heavy metals, on nitrogen removal remains largely unresolved. In this study, a HNAD bacterium (Pseudomonas sp. XF-4) was isolated. It could almost completely remove ammonium and nitrate at pH 5-9 and temperature 20 ℃-35 ℃ within 10 h, and also showed excellently simultaneous nitrification and denitrification efficiency under the coexistence of any two of inorganic nitrogen sources with no intermediate accumulation. XF-4 could rapidly grow again after ammonium vanish when nitrite or nitrate existed. There was no significant effects on nitrification and denitrification when Cd(II) was lower than 10 mg/L, and 95 % of Cd(II) was removed by XF-4. However, electron carrier and electron transport system activity was inhibited, especially at high concentration of Cd(II). Overall, this study reported a novel strain capable of simultaneous nitrification and denitrification coupled with Cd(II) removal efficiently. The results provided new insights into treatment of groundwater or wastewater contaminated by heavy metals and nitrogen.


Asunto(s)
Cadmio , Desnitrificación , Nitrificación , Nitrógeno , Pseudomonas , Contaminantes Químicos del Agua , Cadmio/metabolismo , Pseudomonas/metabolismo , Contaminantes Químicos del Agua/metabolismo , Nitrógeno/metabolismo , Procesos Heterotróficos , Nitratos/metabolismo , Aguas Residuales/microbiología , Aguas Residuales/química , Biodegradación Ambiental , Aerobiosis , Purificación del Agua/métodos , Compuestos de Amonio/metabolismo
7.
J Virol ; 96(22): e0151322, 2022 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-36314820

RESUMEN

Viral infection activates the type I interferons (IFNs) and cellular antiviral responses. Eukaryotic initiation factor 4A-III (eIF4A3) has been shown to promote influenza A virus (IAV) replication by promoting viral mRNA splicing and spliced mRNA nuclear export. Here, we identified eIF4A3 as a negative regulator of virus-triggered type I IFN induction. Our study found that eIF4A3 promoted multiple RNA viruses' replication by binding to IFN regulatory factor 3 (IRF3) and impaired the interaction between tank-binding kinase 1 (TBK1) and IRF3, leading to attenuation of the phosphorylation of IRF3 by TBK1, the formation of IRF3 dimer, and the nuclear translocation of IRF3. This impaired its biological functions in the nucleus, which blocked IRF3 binding to interferon-stimulated response element (ISRE) and the interaction of IRF3 and CBP/p300, resulting in inhibiting the transcription of IFN-ß and downstream IFN-stimulated genes (ISGs), thereby impairing innate antiviral immune responses against RNA viruses. These findings reveal a previously unknown function of eIF4A3 in host innate immunity and establish a mechanistic link between eIF4A3 and IRF3 activation that expands potential therapeutic strategies for viral infectious diseases. IMPORTANCE Production of type I IFN is pivotal for the cellular antiviral immunity. Virus infection leads to the activation of transcription factor IRF3 and subsequent production of type I IFN to eliminate viral infection. Thus, the regulation of IRF3 activity is an important way to affect type I IFN production. IRF3 activation requires phosphorylation, dimerization, and nuclear translocation. Here, we first reported that eIF4A3, a member of DEAD box family, served as a negative regulator of antiviral innate immune responses by inhibiting IRF3 activation. Mechanistically, eIF4A3 binds to IRF3 to impair the recruitment of IRF3 by TBK1, which is independent of eIF4A3 ATP binding, ATPase, and RNA helicase activities. Our study delineates a common mechanism of eIF4A3 promoting replication of different RNA viruses and provides important insights into the negative regulation of host antiviral innate immune responses against virus infections.


Asunto(s)
ARN Helicasas DEAD-box , Factor 4A Eucariótico de Iniciación , Inmunidad Innata , Virus de la Influenza A , Interferón Tipo I , Virosis , Humanos , ARN Helicasas DEAD-box/metabolismo , Factor 4A Eucariótico de Iniciación/metabolismo , Virus de la Influenza A/genética , Virus de la Influenza A/fisiología , Factor 3 Regulador del Interferón/metabolismo , Interferón Tipo I/metabolismo , Fosforilación , ARN Mensajero/metabolismo , Transducción de Señal , Virosis/inmunología , Replicación Viral
8.
J Med Virol ; 95(10): e29171, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37830751

RESUMEN

Influenza A virus (IAV) relies on intricate and highly coordinated associations with host factors for efficient replication and transmission. Characterization of such factors holds great significance for development of anti-IAV drugs. Our study identified protein arginine methyltransferase 5 (PRMT5) as a novel host factor indispensable for IAV replication. Silencing PRMT5 resulted in drastic repression of IAV replication. Our findings revealed that PRMT5 interacts with each protein component of viral ribonucleoproteins (vRNPs) and promotes arginine symmetric dimethylation of polymerase basic 2 (PB2). Overexpression of PRMT5 enhanced viral polymerase activity in a dose-dependent manner, emphasizing its role in genome transcription and replication of IAV. Moreover, analysis of PB2 protein sequences across various subtypes of IAVs demonstrated the high conservation of potential RG motifs recognized by PRMT5. Overall, our study suggests that PRMT5 supports IAV replication by facilitating viral polymerase activity by interacting with PB2 and promoting its arginine symmetric dimethylation. This study deepens our understanding of how IAV manipulates host factors to facilitate its replication and highlights the great potential of PRMT5 to serve as an anti-IAV therapeutic target.


Asunto(s)
Virus de la Influenza A , Proteína-Arginina N-Metiltransferasas , Humanos , Arginina , Virus de la Influenza A/genética , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Ribonucleoproteínas/metabolismo , Replicación Viral
9.
J Med Virol ; 95(6): e28849, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37282768

RESUMEN

The genome of Influenza A virus (IAV) transcribes and replicates in the nucleus of cells and the viral ribonucleoprotein (vRNP) complex plays an important role in viral replication. As a major component of the vRNP complex, the polymerase basic protein 2 (PB2) is translocated to the nucleus via its nuclear localization signals mediated by the importins. Herein, it was identified proliferating cell nuclear antigen (PCNA) as an inhibitor of nuclear import of PB2 and subsequent viral replication. Mechanically, PCNA interacted with PB2 and inhibited the nuclear import of PB2. Furthermore, PCNA decreased the binding efficiency of PB2 with importin alpha (importin α) and the K738, K752, and R755 of PB2 were identified as the key sites binding with PCNA and importin α. Furthermore, PCNA was demonstrated to retrain the vRNP assembly and polymerase activity. Taken together, the results demonstrated that PCNA impaired the nuclear import of PB2, vRNP assembly and polymerase activity, which negatively regulated virus replication.


Asunto(s)
Virus de la Influenza A , Humanos , Transporte Activo de Núcleo Celular , Antígeno Nuclear de Célula en Proliferación/genética , Antígeno Nuclear de Célula en Proliferación/metabolismo , alfa Carioferinas/metabolismo , Ribonucleoproteínas/metabolismo , Replicación Viral
10.
J Biomed Sci ; 30(1): 5, 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36653801

RESUMEN

Autophagy is an evolutionarily conserved catabolic cellular process that exerts antiviral functions during a viral invasion. However, co-evolution and co-adaptation between viruses and autophagy have armed viruses with multiple strategies to subvert the autophagic machinery and counteract cellular antiviral responses. Specifically, the host cell quickly initiates the autophagy to degrade virus particles or virus components upon a viral infection, while cooperating with anti-viral interferon response to inhibit the virus replication. Degraded virus-derived antigens can be presented to T lymphocytes to orchestrate the adaptive immune response. Nevertheless, some viruses have evolved the ability to inhibit autophagy in order to evade degradation and immune responses. Others induce autophagy, but then hijack autophagosomes as a replication site, or hijack the secretion autophagy pathway to promote maturation and egress of virus particles, thereby increasing replication and transmission efficiency. Interestingly, different viruses have unique strategies to counteract different types of selective autophagy, such as exploiting autophagy to regulate organelle degradation, metabolic processes, and immune responses. In short, this review focuses on the interaction between autophagy and viruses, explaining how autophagy serves multiple roles in viral infection, with either proviral or antiviral functions.


Asunto(s)
Virosis , Virus , Humanos , Replicación Viral , Autofagia/fisiología , Antivirales
11.
Microb Ecol ; 86(4): 3027-3042, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37792089

RESUMEN

Deep ocean polymetallic nodules, rich in cobalt, nickel, and titanium which are commonly used in high-technology and biotechnology applications, are being eyed for green energy transition through deep-sea mining operations. Prokaryotic communities underneath polymetallic nodules could participate in deep-sea biogeochemical cycling, however, are not fully described. To address this gap, we collected sediment cores from Nazimov guyots, where polymetallic nodules exist, to explore the diversity and vertical distribution of prokaryotic communities. Our 16S rRNA amplicon sequencing data, quantitative PCR results, and phylogenetic beta diversity indices showed that prokaryotic diversity in the surficial layers (0-8 cm) was > 4-fold higher compared to deeper horizons (8-26 cm), while heterotrophs dominated in all sediment horizons. Proteobacteria was the most abundant taxon (32-82%) across all sediment depths, followed by Thaumarchaeota (4-37%), Firmicutes (2-18%), and Planctomycetes (1-6%). Depth was the key factor controlling prokaryotic distribution, while heavy metals (e.g., iron, copper, nickel, cobalt, zinc) can also influence significantly the downcore distribution of prokaryotic communities. Analyses of phylogenetic diversity showed that deterministic processes governing prokaryotic assembly in surficial layers, contrasting with stochastic influences in deep layers. This was further supported from the detection of a more complex prokaryotic co-occurrence network in the surficial layer which suggested more diverse prokaryotic communities existed in the surface vs. deeper sediments. This study expands current knowledge on the vertical distribution of benthic prokaryotic diversity in deep sea settings underneath polymetallic nodules, and the results reported might set a baseline for future mining decisions.


Asunto(s)
Bacterias , Manganeso , Bacterias/genética , Sedimentos Geológicos/microbiología , Níquel , Filogenia , ARN Ribosómico 16S/genética , Cobalto
12.
Bioorg Chem ; 131: 106340, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36586301

RESUMEN

7ß-Hydroxysteroid dehydrogenases (7ß-HSDHs) have attracted increasing attention due to their crucial roles in the biosynthesis of ursodeoxycholic acid (UDCA). However, most published 7ß-HSDHs are strictly NADPH-dependent oxidoreductases with poor activity and low productivity. Compared with NADPH, NADH is more stable and cheaper, making it the more popular cofactor for industrial applications of dehydrogenases. Herein, by using a sequence and structure-guided genome mining approach based on the structural information of conserved cofactor-binding motifs, we uncovered a novel NADH-dependent 7ß-HSDH (Cle7ß-HSDH). The Cle7ß-HSDH was overexpressed, purified, and characterized. It exhibited high specific activity (9.6 U/mg), good pH stability and thermostability, significant methanol tolerance, and showed excellent catalytic efficiencies (kcat/Km) towards 7-oxo-lithocholic acid (7-oxo-LCA) and NADH (70.8 mM-1s-1 and 31.8 mM-1s-1, respectively). Molecular docking and mutational analyses revealed that Asp42 could play a considerable role in NADH binding and recognition. Coupling with a glucose dehydrogenase for NADH regeneration, up to 20 mM 7-oxo-LCA could be completely transformed to UDCA within 90 min by Cle7ß-HSDH. This study provides an efficient approach for mining promising enzymes from genomic databases for cost-effective biotechnological applications.


Asunto(s)
Hidroxiesteroide Deshidrogenasas , NAD , Ácido Ursodesoxicólico , Hidroxiesteroide Deshidrogenasas/química , Hidroxiesteroide Deshidrogenasas/metabolismo , Simulación del Acoplamiento Molecular , NAD/química , NADP/química , Ácido Ursodesoxicólico/biosíntesis
13.
Bioorg Chem ; 136: 106533, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37084587

RESUMEN

Penicillin G acylase (PGA) is a key biocatalyst for the enzymatic production of ß-lactam antibiotics, which can not only catalyze the synthesis of ß-lactam antibiotics but also catalyze the hydrolysis of the products to prepare semi-synthetic antibiotic intermediates. However, the high hydrolysis and low synthesis activities of natural PGAs severely hinder their industrial application. In this study, a combinatorial directed evolution strategy was employed to obtain new PGAs with outstanding performances. The best mutant ßF24G/ßW154G was obtained from the PGA of Achromobacter sp., which exhibited approximately a 129.62-fold and a 52.55-fold increase in specific activity and synthesis/hydrolysis ratio, respectively, compared to the wild-type AsPGA. Thereafter, this mutant was used to synthesize amoxicillin, cefadroxil, and ampicillin; all conversions > 99% were accomplished in 90-135 min with almost no secondary hydrolysis byproducts produced in the reaction. Molecular dynamics simulation and substrate pocket calculation revealed that substitution of the smallest glycine residue at ßF24 and ßW154 expanded the binding pocket, thereby facilitating the entry and release of substrates and products. Therefore, this novel mutant is a promising catalyst for the large-scale production of ß-lactam antibiotics.


Asunto(s)
Achromobacter , Penicilina Amidasa , Penicilina Amidasa/metabolismo , Achromobacter/metabolismo , Antibacterianos/farmacología , Antibacterianos/metabolismo , Ampicilina/metabolismo , Amoxicilina/metabolismo , Monobactamas
14.
Int J Mol Sci ; 24(4)2023 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-36835584

RESUMEN

Classified as a class B infectious disease by the World Organization for Animal Health (OIE), bovine viral diarrhea/mucosal disease is an acute, highly contagious disease caused by the bovine viral diarrhea virus (BVDV). Sporadic endemics of BVDV often lead to huge economic losses to the dairy and beef industries. To shed light on the prevention and control of BVDV, we developed two novel subunit vaccines by expressing bovine viral diarrhea virus E2 fusion recombinant proteins (E2Fc and E2Ft) through suspended HEK293 cells. We also evaluated the immune effects of the vaccines. The results showed that both subunit vaccines induced an intense mucosal immune response in calves. Mechanistically, E2Fc bonded to the Fc γ receptor (FcγRI) on antigen-presenting cells (APCs) and promoted IgA secretion, leading to a stronger T-cell immune response (Th1 type). The neutralizing antibody titer stimulated by the mucosal-immunized E2Fc subunit vaccine reached 1:64, which was higher than that of the E2Ft subunit vaccine and that of the intramuscular inactivated vaccine. The two novel subunit vaccines for mucosal immunity developed in this study, E2Fc and E2Ft, can be further used as new strategies to control BVDV by enhancing cellular and humoral immunity.


Asunto(s)
Virus de la Diarrea Viral Bovina Tipo 2 , Inmunidad Mucosa , Vacunas Virales , Animales , Bovinos , Humanos , Anticuerpos Antivirales , Diarrea , Células HEK293 , Vacunas de Subunidad/inmunología , Vacunas Virales/inmunología , Síndrome Hemorrágico de los Bovinos/prevención & control
15.
J Sci Food Agric ; 103(3): 1303-1314, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36116126

RESUMEN

BACKGROUND: 2'-Fucosyllactose, a representative oligosaccharide in human milk, is an emerging and promising food and pharmaceutical ingredient due to its powerful health benefits, such as participating in immune regulation, regulation of intestinal flora, etc. To enable economically viable production of 2'-fucosyllactose, different biosynthesis strategies using precursors and pathway enzymes have been developed. The α-1,2-fucosyltransferases are an essential part involved in these strategies, but their strict substrate selectivity and unsatisfactory substrate tolerance are one of the key roadblocks limiting biosynthesis. RESULTS: To tackle this issue, a semi-rational manipulation combining computer-aided designing and screening with biochemical experiments were adopted. The mutant had a 100-fold increase in catalytic efficiency compared to the wild-type. The highest 2'-fucosyllactose yield was up to 0.65 mol mol-1 lactose with a productivity of 2.56 g mL-1  h-1 performed by enzymatic catalysis in vitro. Further analysis revealed that the interactions between the mutant and substrates were reduced. The crucial contributions of wild-type and mutant to substrate recognition ability were closely related to their distinct phylotypes in terms of amino acid preference. CONCLUSION: It is envisioned that the engineered α-1,2-fucosyltransferase could be harnessed to relieve constraints imposed on the bioproduction of 2'-fucosyllactose and lay a theoretical foundation for elucidating the substrate recognition mechanisms of fucosyltransferases. © 2022 Society of Chemical Industry.


Asunto(s)
Fucosiltransferasas , Lactosa , Humanos , Fucosiltransferasas/genética , Fucosiltransferasas/metabolismo , Lactosa/metabolismo , Trisacáridos , Oligosacáridos/química
16.
Angew Chem Int Ed Engl ; 62(33): e202306712, 2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37365795

RESUMEN

The classic solvent system can't sufficiently separate one-dimensional edge-sharing SnI2 crystals in solution, which severely restricts the fabrication of high-quality tin-based perovskite film. Herein, a strong Lewis base (hexamethylphosphoramide, HMPA) has been introduced to coordinate Sn2+ to modulate solvation behaviours on perovskite precursor and regulate crystallization kinetics. The large molecular volume of HMPA and stronger bind energy of SnI2 ⋅ 2HMPA (-0.595 eV vs -0.118 eV for SnI2 ⋅ 2DMSO) change the solvation structure of SnI2 from edge-sharing cluster to monodisperse adduct, which contributes to uniform nucleation sites and prolongs crystal growth process. Delightfully, a fully-covered perovskite film is formed on the large-area substrate and tin-based perovskite solar cells processed with HMPA exhibit an excellent efficiency of 13.46 %. This research provides novel insights and directions for the solution preparation of smooth and uniform large-area tin-based perovskite film.

17.
Int Microbiol ; 25(3): 541-550, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35175436

RESUMEN

Low pH eliminated the jarosite accumulation and improved the interfacial reaction rate during the bioleaching process. However, high acidity tends to make environments less hospitable, even for organisms that live in extreme places, so a great challenge existed for bioleaching at low pH conditions. This study demonstrated that the adaption and bioleaching ability of Leptospirillum ferriphilum could be improved after the long-term adaptive evolution of the community under acidity conditions. It was found that the acidity-adapted strain showed robust ferrous iron oxidation activity in wider pH, high concentration of ferrous iron, and lower temperature. Although the enhancement for heavy metal tolerance was limited, the resistance for MgSO4, Na2SO4, and organic matter was stimulative. More importantly, both pyrite and printed circuit board bioleaching revealed the higher bioleaching ability of the acid-resistant strain. These adaptation and bioleaching details provided an available approach for the improvement of bioleaching techniques.


Asunto(s)
Bacterias , Hierro , Adaptación Fisiológica , Oxidación-Reducción
18.
Inorg Chem ; 61(18): 7095-7102, 2022 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-35465672

RESUMEN

Developing highly efficient, low-cost, and durable oxygen evolution reaction (OER) electrocatalysts is extraordinarily desirable for achieving clean and sustainable hydrogen energy. Metal-organic frameworks (MOFs) are emerging as attractive candidates for OER electrocatalysts. Herein, a two-dimensional Fe-Ni MOF of Fe(py)2Ni(CN)4 (py = pyridine) is synthesized controllably to generate various nanostructures, including nanoboxes, nanocubes, nanoplates, and nanosheets. Since different morphologies expose different active crystal planes and generate disparate intrinsic active sites, these nanostructures exhibit obviously different electrocatalytic activities. Particularly, the nanoboxes with a hollow structure display superior electrocatalytic activity and stability for OER due to greater active surface area and higher intrinsic activity of the exposed crystal planes, delivering a low overpotential of 285 mV at 10 mA cm-2 and a small Tafel value of 50.9 mV dec-1 in a 1.0 M KOH solution. The morphology-dependent electrocatalytic properties demonstrated in this work provide an efficient strategy to optimize MOF precatalysts for electrochemical energy storage and conversion.

19.
Inorg Chem ; 61(35): 14187-14194, 2022 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-35998715

RESUMEN

Development of effective electrocatalysts toward hydrogen oxidation with a low content of noble metals has attracted the attention of the catalytic community. In this work, a novel catalyst composed of nitrogen-doped carbon acting as the substrate and Ir nanoclusters as active species was prepared, which was then employed as an effective catalyst for the hydrogen oxidation reaction (HOR) in an alkaline electrolyte. In 0.1 M KOH, the optimized catalyst provides an exchange current density of 0.144 mA cmIr-2 for HOR that outperforms the catalytic activity of the commercial Pt/C catalyst with a Pt content of 20 wt %. The substrate induces highly active Ir sites that markedly boosted the electrocatalytic activity for HOR. The nitrogen-doped carbon substrate increases the stability of Ir nanoclusters and decreases the absorption energy of hydrogen on Ir sites; at the same time, the higher electrostatic potential around the adsorbed hydrogen on Ir/N-doped carbon also enables them to be easily attracted by OH- species, both of which enhanced the catalytic activity. The excellent catalytic activity and the understanding shown here will give some hints for the development of HOR catalysts used in alkaline electrolytes.

20.
Appl Microbiol Biotechnol ; 106(11): 4211-4221, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35622123

RESUMEN

A high production mutated strain Bacillus thuringiensis X023PN (BtX023PN) was screened from the wild strain Bacillus thuringiensis X023 (BtX023) after atmospheric and room temperature plasma (ARTP) and nitrosoguanidine (NTG) mutation. BtX023PN grows faster than the wild strain, and its lysis of mother cell was 6 h ahead BtX023, but the ability of sporulation was significantly reduced. Bioassay indicated that compared with the wild type strain, the virulence of BtX023PN against Plutella xylostella (P. xylostella) and Mythimna seperata (M. seperata) increased to 2.33-fold and 2.13-fold respectively. qRT-PCR and SDS-PAGE demonstrated that the production of Cry1Ac increased by 61%. Resequence indicated that the mutated sites enriched on the key carbohydrate metabolism and amino acid metabolism. This study provides a new strain resource for the development of Bt insecticides and a feasible technical strategy for the breeding of Bt. KEY POINTS: • Atmospheric and room temperature plasma used in breeding of Bacillus thuringiensis. • Less stationary phase time with more ICP production. • Semi-lethal concentration against Plutella xylostella reduced by about 57.


Asunto(s)
Bacillus thuringiensis , Mariposas Nocturnas , Animales , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/metabolismo , Endotoxinas/genética , Endotoxinas/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Larva , Mutación , Nitrosoguanidinas , Virulencia
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