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Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious viral disease that causes significant economic losses to the swine industry worldwide. PRRS virus (PRRSV) infection is a receptor-mediated endocytosis and replication process. The purpose of this study was to determine the localization and expression of four important PRRSV receptors in immunological organs of piglets. After piglets were infected with PRRSV, Hematoxylin and Eosin staining, immunofluorescence, and Western blot were used to perform histopathological examination and receptors distribution analysis. The results showed that PRRSV caused severe damage to the piglets' immune organs, including atrophy of the thymus and swelling of lymph node. Histopathological lesions were mainly observed in the lung and lymph node and were characterized by interstitial pneumonia, collapsed follicles, exhaustion of germinal centers, and extensive hemorrhage. Immunofluorescence staining and Western blot results showed that the receptors of CD163 and NMHCII-A were mainly distributed in the thymus, hilar lymph nodes, and mesenteric lymph nodes. However, Sn and vimentin receptors were expressed at low levels in the immune organs of piglets. The distribution of the four receptors in the immune organs was more concentrated in the cortex but was more scattered in the medulla. Compared to the control group, the relative expression of the four receptors increased significantly in most immune organs after viral infection. In conclusion, our study examined the distribution and expression of four PRRSV receptors in immunological organs. We observed a significant increase in the expression of Sn, CD163, and vimentin following viral infection. These findings may provide potential targets for future antiviral reagent design or vaccine development. [ABSTRACT FROM AUTHOR]

Speech recognition often relies on visual stereo images and videos, but it is often limited by light intensity and opaque occlusions such as masks (such as during the coronavirus disease 2019 (COVID-19) pandemic). Lip speech is produced by the movement of a series of muscles in the mouth. Therefore, lip-reading extraction and decoding can be achieved by attaching non-invasive sensors to capture muscle movement. Herein, we prepared a highly sensitive and stretchable CuNW-rGO/PDMS piezoresistive strain sensor based on a biomimetic pearl "brick-mortar" structure by using two-dimensional rGO and conductive stretchable one-dimensional Cu NWs as mixed "bricks" and stretchable PDMS as the "mortar". The strain sensor shows a high sensitivity with a gauge factor of 26 in the stretching ability range of up to 70% and high durability over 1000 stretching–releasing cycles. This sensor can act as a health monitoring device when attached to human skin, detecting various human motions such as hand clenching, elbow bending, wrist pulse beating and lip-reading motion. Effective recognition of the lip reading signal was achieved by processing the lip-reading signal using a dynamic time regularization algorithm and Euclidean distance. Finally, a full system integration to real-time analyze and feedback speech information with voice broadcast and text display function based on the strain sensor was presented for accurate speech recognition, which opens up a new possibility for translating lip motion to speech or text directly by capturing lip muscle movements. This work presents a promising way to help people with vocal cord lesions or laryngeal and lingual injuries live a happy life with barrier-free communication and will enrich the diversity of lip-language translation systems in human–machine interfaces and silent speech interfaces. [ABSTRACT FROM AUTHOR]

The efficient biosynthesis of chiral amines at an industrial scale to meet the high demand from industries that require chiral amines as precursors is challenging due to the poor stability and low catalytic efficiency of ω-transaminases (ω-TAs). Herein, this study adopted a green and efficient solvent engineering method to explore the effects of various aqueous solutions of deep eutectic solvents (DESs) as cosolvents on the catalytic efficiency and stability of ω-TA. Binary- and ternary-based DESs were used as cosolvents in enhancing the catalytic activity and stability of a ω-TA variant from Aspergillus terreus (E133A). The enzyme exhibited a higher catalytic activity in a ternary-based DES that was 2.4-fold higher than in conventional buffer. Moreover, the thermal stability was enhanced by a magnitude of 2.7, with an improvement in storage stability. Molecular docking studies illustrated that the most potent DES established strong hydrogen bond interactions with the enzyme's amino acid, which enhanced the catalytic efficiency and improved the stability of the ω-TA. Molecular docking is essential in designing DESs for a specific enzyme. [ABSTRACT FROM AUTHOR]

The application of lignin-based adsorbents in the efficient removal of phosphate from wastewater has attracted much attention and been intensively studied in recent years. However, most currently reported lignin-based adsorbents are difficult to recover and recycle. Herein, we have developed a recyclable, nanostructured bio-adsorbent, poly(ethyleneimine) (PEI)-modified lignin (LG) integrated with Fe3O4 and Zr-La dual-metal hydroxide (LG-NH2@Fe3O4@Zr-La), by the Mannich reaction followed by the chemical coprecipitation method. Multilayer adsorption existed on the surface of LG-NH2@Fe3O4@Zr-La based on the isotherm fitting curve, and its adsorption capacity reached 57.8 mg P g−1, exhibiting a higher phosphate uptake than most reported metallic oxide-based composites. The adsorption process was dominated by inner-sphere complexation of ligand-exchange and electrostatic interactions. Moreover, LG-NH2@Fe3O4@Zr-La exhibited excellent selectivity against coexisting anions, and the adsorption was more efficient under acidic conditions. When the phosphate concentration was 2.0 mg P L−1, the removal efficiency of phosphate reached 99.5% and the residual concentration was only 10 μg P L−1, which meets the United States Environmental Protection Agency (USEPA) standard for eutrophication prevention. In addition, the LG-NH2@Fe3O4@Zr-La displayed excellent reusability, maintaining 91.8% of removal efficiency after five cycles. Importantly, owing to the magnetic properties of the loaded Fe3O4, the resulting composite could be separated within 30 s under an external magnetic field. Thus, the separable and recyclable biobased magnetic adsorbent developed in this work exhibited promising application in phosphate capture from real sewage. This research study provides a new perspective for lignin valorization in lignocellulose biorefineries and establishes an approach for developing an economical and efficient bio-adsorbent for phosphate removal from wastewater. [ABSTRACT FROM AUTHOR]

Background. Fuzi-Lizhong decoction (FLD) derives from the ancient Chinese Pharmacopoeia and has been clinically used for years. The present study aimed to investigate the activities and underlying mechanisms of FLD against nonalcoholic fatty liver disease (NAFLD). Methods. In vivo studies were conducted by inducing NAFLD in rats with a high-fat diet, and in vitro studies were performed on HL-7702 cells treated with oleic and linoleic acids. Total cholesterol (TC), triglyceride (TG), and blood glucose (Glu) levels were detected using an automatic biochemical analyzer. The expression of IL-2, IL-6, and TNF-α in sera and cell culture supernatants was measured by ELISA. The mRNA and protein levels of TLR4, MyD88, and TRAF6 were measured in liver tissue and HL-7702 cells using reverse transcription-quantitative polymerase chain reaction and western blot. Results. FLD significantly reduced the TC, TG, Glu, FFA, IL-2, IL-6, and TNF-α levels in NAFLD rats and HL-7702 cells. Analysis of liver lipid content by Oil Red O staining revealed a significant increase in hepatic lipid accumulation in rats with NAFLD, but this lipid accumulation was reversed by FLD treatment. In addition, the mRNA expression levels of TLR4, MyD88, TRAF6, and NF-κB p65 as well as the protein levels of TLR4, MyD88, TRAF6, and NF-κB p65 were decreased after FLD treatment. FLD significantly reduced inflammation and improved collagen accumulation in vivo and in vitro by inhibiting the activation of the TLR4/MyD88/TRAF6 signaling pathway. Conclusions. FLD exerted potent protective effects against NAFLD via TLR4/MyD88/TRAF6 signaling. These findings provide novel insights into the mechanisms whereby this compound acts as an anti-inflammatory agent and highlight the potential application of FLD in the treatment of acute liver failure (ALF). [ABSTRACT FROM AUTHOR]

Emerging evidence has demonstrated that N6‐methyladenosine (m6A) and long noncoding RNAs (lncRNAs) are both crucial regulators in gastric cancer (GC) tumorigenesis. However, the interaction of m6A and lncRNAs in GC progression are still unclear. Here, our team discovered that lncRNA LINC00958 expression up‐regulated in GC tissue and cells. Clinically, high‐expression of LINC00958 was clinically correlated to lower survival of GC patients. Functionally, in vitro assays demonstrated that LINC00958 promoted the GC cells' aerobic glycolysis. Mechanistically, methylated RNA immunoprecipitation sequencing (MeRIP‐Seq) found that there were m6A‐modificated sites in LINC00958, and moreover m6A methyltransferase KIAA1429 catalyzed the m6A modification on LINC00958 loci. Moreover, LINC00958 interacted with GLUT1 mRNA via the m6A‐dependent manner to enhance GLUT1 mRNA transcript stability, thereby positively regulating the aerobic glycolysis of GC. In conclusion, our findings reveal the function and mechanism of KIAA1429‐induced LINC00958 in GC, delineating novel understanding of m6A‐lncRNA in cancer biology. [ABSTRACT FROM AUTHOR]

Biotechnological production of 2,3-butanediol (2,3-BD), a versatile platform bio-chemical and a potential biofuel, is limited due to by-product toxicity. In this study, we aimed to redirect the metabolic flux toward 2,3-BD in Enterobacter aerogenes (E. aerogenes) by increasing the intracellular NADH pool. Increasing the NADH/NAD+ ratio by knocking out the NADH dehydrogenase genes (nuoC / nuoD) enhanced 2,3-BD production by up to 67% compared with wild-type E. aerogenes. When lactate dehydrogenase (ldh) was knocked out, the yield of 2,3-BD was increased by 71.2% compared to the wild type. Metabolic flux analysis revealed that upregulated expression of the sRNA RyhB led to a noteworthy shift in metabolism. The 2,3-BD titer of the best mutant Ea-2 was almost seven times higher than that of the parent strain in a 5-L fermenter. In this study, an effective metabolic engineering strategy for improved 2,3-BD production was implemented by increasing the NADH/NAD+ ratio and blocking competing pathways. [ABSTRACT FROM AUTHOR]

Tetrastigma hemsleyanum Diels et Gilg (Sanyeqing, SYQ) is a perennial climbing liana and an endemic plant to southern China. Its tuberous roots (TRs) are used in traditional Chinese medicine for treating some diseases such as high fever, pneumonia, asthma, hepatitis, and cancers. However, the mechanisms underlying the development of TR and the content of flavonoids and phenylpropanoids (FPs) are not well-understood. In this study, we performed a transcriptomic analysis of 12 fully developed TR (FD-TR) samples harvested in four seasons [spring (Sp), summer (Su), autumn (Au), and winter (Wi)] using the RNA-Sequencing (RNA-Seq). We obtained a total of 78.54 Gb raw data and 65,578 unigenes. Then, the unigenes were annotated by using six databases such as non-redundant protein database (NR), Pfam, eggNOG, SWISSProt, Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene ontology (GO). The transcriptomic profiling showed closer relationships between the samples obtained in Su and Au than those obtained in Sp and Wi based on the results of both total unigenes and differentially expressed genes (DEGs). Three pathways, including the biosynthesis of FPs, metabolism of starch and sucrose, and signaling of phytohormones, were highly enriched, suggesting a gene-level seasonal variation. Based on the numbers of DEGs, brassinosteroid (BR) signal transduction factors appeared to play a key role in modulating the development of TRs while most of the auxin signaling genes were mainly activated in Wi and Sp FD-TRs. Most genes in the biosynthesis and biodegradation of starch and biodegradation of cellulose were activated in Wi FD-TRs. As determined by the high performance liquid chromatography (HPLC) and aluminum nitrate colorimetric method, the contents of total flavonoids and most detected FP components increased from Sp to Au but decreased in Wi. Enhanced expression levels of some genes in the biosynthetic pathways of FPs were detected in Su and Au samples, which corroborated well with metabolite content. Our findings provide the first transcriptomic and biochemical data on a seasonal variation in the composition of medically important metabolites in SYQ FD-TRs. [ABSTRACT FROM AUTHOR]

Laser diodes (LDs) packaged with transparent ceramics show the low thermal expansion coefficient and high thermal conductivity, but there is a problem of the low color render index (CRI) owing to the lack of red component in current transparent ceramics. Mn2+ doped garnet transparent ceramics with adjustable color from yellow to red have been prepared via a solid‐state reaction‐vacuum sintering process, which have a high transmittance of 78.6% at 800 nm. Two main emission peaks of this ceramic are monitored at 590 and 749 nm, and the gratifying luminous performance improvement is obtained due to the charge compensation effect, electron cloud expansion effect, and efficient energy transfer. LD system fabricated with the obtained ceramics and blue LD shows a high‐CRI of 80, low correlated color temperature of 4098 K, and good luminous efficiency of 96.91 m/W. [ABSTRACT FROM AUTHOR]

Laser diode (LD) lighting is highly luminescent and safe due to the replacement of traditional wires with optical fibers, and is suitable for museum lighting. However, the current LD lighting has a low color rendering index (CRI) that affects the visual splendor because of the lack of a red component in the spectra of the photoluminescent transparent ceramic (TC). In this study, a series of Lu2.98Al5−2xSixO12:0.02Ce3+, xMn2+ (x = 0–0.12) photoluminescent TCs with a transmittance of T = 48.5–78% and a spectrum adjustable from 500 to 800 nm are synthesized, which show excellent thermal stability. Their photoluminescence property is retained at 99% of the initial value at 425 K when the doping of Mn2+ is x = 0.01. The color rendering index of the LD system assembled with these photoluminescent TCs and high-power blue LDs reached 80.1, while the correlated-color temperature (CCT) is 3298 K. These characteristics shows the LD system is promising for application in museum lighting. [ABSTRACT FROM AUTHOR]

Objective. Sijunzi, Lizhong, and Fuzilizhong decoction were traditional Chinese classic formulations, which are widely used in clinical treatment, and the underlying mechanism is unclear. In this study, we aim to investigate the molecular mechanisms underlying the protective effects of Sijunzi, Lizhong, and Fuzilizhong on nonalcoholic fatty liver disease (NAFLD). Methods. Male Wistar rats were fed a high-fat diet for four weeks to induce NAFLD and were thereafter administered Sijunzi (8 g/kg/d), Lizhong (10 g/kg/d), or Fuzilizhong (10 g/kg/d) by gavage for four weeks. Hepatic damage, lipid accumulation, inflammation, autophagy, and peroxisome proliferator-activated receptor-α signaling were evaluated. Results. The high-fat diet-fed rats showed typical symptoms of NAFLD, including elevated levels of hepatic damage indicators, increased hepatic lipid deposition and fibrosis, severe liver inflammation, and prominent autophagy. Upon administration of Sijunzi, Lizhong, and Fuzilizhong, liver health was improved remarkably, along with ameliorated symptoms of NAFLD. In addition, NAFLD-suppressed peroxisome proliferator-activated receptor-α signaling was reactivated after treatment with the three types of decoctions. Conclusions. The results collectively signify the effective therapeutic and protective functions of Sijunzi, Lizhong, and Fuzilizhong against NAFLD and demonstrate the potential of Chinese herbal medication in mitigating the symptoms of liver diseases. Novelty of the Work. Traditional Chinese herbal medicine has been used for centuries to treat various diseases, but the molecular mechanisms of individual ingredients have rarely been studied. The novelty of our work lies in elucidating the specific signaling pathways involved in the control of NAFLD using three common Chinese herbal decoctions. We suggest that natural herbal formulations can be effective therapeutic agents to combat against NAFLD. [ABSTRACT FROM AUTHOR]

In this study, a new composite of low-temperature selective catalytic reduction (LT-SCR) catalyst is synthesized by impregnating MnO x onto ZnO nanorod arrays integrated with cordierite ceramic substrate (MnO x -ZnO/CC), which exhibits improved activities at 100–250 °C compared to its analogue that fabricated from TiO 2 nanorod arrays (MnO x -TiO 2 /CC). By optimizing the synthesis conditions, the MnO x -ZnO/CC catalyst obtains a maximum NO x conversion efficiency of 96.8% at 200 °C. The introduction of ZnO nanorod arrays not only provides a high surface area, but also results in the formation of amorphous MnO x. A higher content of Mn4+, proper ratio of surface-adsorbed oxygen (O α), and more Lewis acid sites are found on the surface of the MnO x -ZnO/CC catalyst than that on the MnO x -TiO 2 /CC counterpart. Additional information about the reaction mechanism is systematically investigated via in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS), the results of which demonstrate that the LT-SCR reactions over the MnO x -ZnO/CC catalyst generally occur between NO x and NH 3 species in the adsorption status, following the Langmuir-Hinshelwood pathway. The enhanced activities can be attributed to the generation of abundant NH 4 NO 3 originating from NO 2 in the "Fast SCR" route, because the synergistic effect between MnO x and ZnO facilitates the oxidation of NO. Unlabelled Image • A competitive SCR catalyst is synthesized by loading MnO x onto ZnO nanorod arrays. • The MnO x on ZnO nanorod arrays reveals amorphous state. • Fast SCR reactions are promoted with a high content of Mn4+ and proper ratio of O α. • The overall NH 3 -SCR pathway follows the L-H mechanism. [ABSTRACT FROM AUTHOR]

Gasification is a promising technology to utilize solid wastes. Co-gasification of high-ash sewage sludge and straw were studied in a fluidized bed using oxygen-enriched air. Several factors influencing co-gasification performance were investigated, including the blending ratio of straw (BR, 0–100 %), the oxygen percentage of enriched air (OP, 30.2–50 %) and the bed material type (high alumina bauxite, calcined dolomite and olivine). The results indicated that the proper increase in BR led to higher syngas yield and an increase in OP caused an increase in combustible gas components, both showing improvements for waste gasification. Correspondingly, the maximum cold gas efficiency was obtained at BR of 50 % and OP of 44.7 %, respectively. Additionally, calcined dolomite exhibited the maximum advantage in the reduction of heavy polycyclic aromatic hydrocarbons (PAHs), promoting the production of H2 and CO. The addition of high alumina bauxite was favored for improving syngas yield and gasification efficiency. [ABSTRACT FROM AUTHOR]

Based on the refraction characteristic of uniform and transparent liquid, the measurement error of the liquid refractive index using the internal standard method is analyzed, and an improved laser speckle method is proposed. This method designs a double-cell structure composed of two identical rectangular parallelepiped glass cells with one cell containing the liquid to be measured and the other one being empty. This double-cell structure is placed in the built optical system based on laser speckle, and then the refractive indices of sodium chloride solution and sucrose solution with various concentrations are measured by the improved method. Compared with the measurement values of the Abbe refractometer and the internal standard method, the results show that the improved method can significantly reduce the measurement error and improve the measurement accuracy. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide with alarming prevalence. Due to its complex pathogeneses and considerable individual heterogeneity in disease, there is no specific medication to NAFLD safely and effectively. Therefore, there is a great need to explore complementary and alternative therapies. Xiaoyao Powder (XYP), a classic Chinese formula, has been tremendously applied to gastrointestinal diseases, especially non-alcoholic fatty liver disease. However, the efficacy and safety of XYP have not been fully assessed. To assess the effectiveness and safety of XYP for NAFLD. The assigned registration number on the PROSPERO platform of this meta-analysis is CRD42020192154, and we strictly followed the protocol. We searched eight primary databases from their inception to June 2020. Two authors independently identified random controlled trials (RCTs) of XYP for NAFLD and evaluated the quality of the retrieved articles by Cochrane accessing risk bias tool. At least one of the following indices was thoroughly documented for outcome measurement: total effective rate, total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyl transpeptidase (GGT), body mass index (BMI), and adiponectin. We calculated risk ratio (RR) and mean difference (MD) for dichotomous data and continuous variables with a 95% confidence interval (CI). R 4.0.5 software was employed for data synthesis. Consequently, we identified 12 studies with 1012 participants. XYP, whether individually or combined with essential treatment, ameliorated NAFLD regardless of the course of the disease or curative duration. This benefit was mainly driven by regulating levels of serum markers, involving TC, TG, ALT, AST, GGT, and adiponectin. Three studies where statins were concerned about drug safety reported several adverse events with clinical symptoms, varying from flatulence, constipation, and diarrhea to rash, whereas others did not. Our findings provided evidence that XYP is a therapeutic option to treat NAFLD effectively and safely. Notwithstanding, a precise and comprehensive conclusion calls for RCTs on a larger scale with more rigorous designs considering the inferior methodological quality and limited retrieved articles. [Display omitted] [ABSTRACT FROM AUTHOR]

Vuilleumier machines are a promising technology for heating. Respective performances of Vuilleumier's engine and cooler are generally unclear. In Stirling machines, performances can be determined based on PV power flow and heat flow methods. In this work, respective performances based on two methods in current Vuilleumier models were investigated. It was found that PV power flow and heat flow methods in current Vuilleumier models were ineffective for analysis of respective performances due to there being no piston as a boundary between Vuilleumier's engine and cooler. Then, a virtual piston was assumed, and a virtual piston based Vuilleumier model (VPBVM) was developed. The relative Carnot efficiencies of the obtained engine and cooler were 53~64% and 43~49%, respectively, at conditions of 550 °C hot temperature, 50~70 °C warm temperature, and −20~10 °C cold temperature. The results indicated that respective performances obtained in VPBVM were reasonable. Moreover, the engine's compression ratios could be obtained in VPBVM and were 1.2~1.24. Thus, VPBVM could be effective for the analysis of the Vuilleumier machine's engine and cooler. [ABSTRACT FROM AUTHOR]

The development of a facile and efficient approach to prepare high‐toughness epoxy resin is vital but has remained an enormous challenge. Herein, we have developed a high‐performance environment‐friendly solid epoxy resin modified with epoxidized hydroxyl‐terminated polybutadiene (EHTPB) via one‐step melt blending. The characterization, mechanical performance, curing behavior, and thermal properties of EHTPB‐modified epoxy resin were investigated. EHTPB‐modified epoxy resin exhibited excellent toughness with a 100% increase in elongation at break of tensile than that of neat epoxy resin. The transfer stress and dissipated energy in the rubber phase were predominant mechanisms of toughening. The toughening effect of EHTPB on solid epoxy resin was better than that of some of the previously reported liquid epoxy resins. Meanwhile, at 10 wt % of EHTPB loading, the EHTPB‐modified epoxy resin displayed high strength and 22 and 101% improvement of flexural strength and impact strength, respectively. Moreover, at 10 wt % of EHTPB loading, the activation energy of EHTPB‐modified epoxy resin for curing reaction decreased from 73.89 to 65.12 kJ·mol−1, which is beneficial for the curing reaction. Furthermore, EHTPB‐modified epoxy resin had a good thermal stability and the initial degradation temperature increased from 249 to 313 °C at 10 wt % of EHTPB loading. This work provides a simple‐preparation and highly efficient and large‐scale approach for the production of high‐toughness environment‐friendly solid epoxy resins. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48596. [ABSTRACT FROM AUTHOR]

Biotechnological hydrogen production is considered as an environmentally sustainable alternative to petrochemical sources or electrolysis. Here, disruption of lactate dehydrogenase (LDH) and metabolic regulation via the small RNA RyhB were adopted to improve hydrogen production in the novel Klebsiella sp. strain FSoil 024. The hydrogen production of FSoil 024-L (Δ ldh) and FSoil 024-L/R (Δ ldh /RyhB) from glucose in a 5-L fermenter respectively increased by 40 and 50% compared to the wild type. When glycerol was adopted as a more favorable substrate, FSoil 024-L generated 3.3 L/L of hydrogen after 52 h of fermentation, implying its great potential for the utilization of crude glycerol to produce hydrogen. Overexpression of RyhB downregulated formate biosynthesis in FSoil 024, thereby redirecting NADH toward the hydrogen production pathway. This finding provides new insights into the role of cellular reducing power in hydrogen metabolism and establishes a rationale for improving hydrogen production. [Display omitted] • Deletion of ldh redirected NADH to hydrogen production in FSoil 024. • RyhB downregulated formate biosynthesis thus improving hydrogen yield in FSoil 024. • FSoil 024-L exhibited great potential of hydrogen production using crude glycerol. • Hydrogen yield of FSoil 024-L/R increased by 50% with glucose in 5-L fermenter. [ABSTRACT FROM AUTHOR]

Biohydrogen is a sustainable clean energy source that has received significant attention in recent years. In this study, the strategies to regulate NADH supply and metabolic flux via disruption of nuoF gene in complex Ⅰ, over-expression formate hydrolyase activator (fhlA) and phosphoenolpyruvate carboxykinase (pckA) were taken to improve hydrogen production in Enterobacter aerogenes IAM1183. After knocking out nuoF and overexpressing pckA , experimental results indicated that the intracellular NADH/NAD+ ratio was significantly increased, which was 115.6% higher than before in the optimal strain EaΔCDEF/P (Δ nuoCDEF / pckA), thereby improving the hydrogen production of NADH pathway. After overexpressing fhlA , the hydrogen production of Ea/F via formate pathway increased by 16.8%. Through the multi-gene engineering strategy, the metabolic flux of mutants was reallocated and the concentration of fermentation metabolites was changed. The total hydrogen production of EaΔCDEF/P reached 4.5 L after 44 h in 5-L fermenter, which was 17.2% higher than that of the original strain. This study provides new concepts for the use of genetic engineering to promote bacterial hydrogen production. • Disruption of nuoF and overexpression of pckA can increase the NADH/NAD+ ratio. • The regulation of NADH/NAD+ significantly altered NADH pathway hydrogen yield. • In the formate pathway, fhlA affects H 2 production by regulating formate synthesis. • Hydrogen yield produced by EaΔCDEF/P increased 17.2% in 5-L fermenter. [ABSTRACT FROM AUTHOR]