المؤلفون: Zhang, Yun, Wang, Xueliang, Odesanmi, Christianah, Hu, Qitiao, Li, Dandan, Tang, Yuan, Liu, Zhe, Mi, Jie, Liu, Shuwen, Wen, Tingyi

المساهمون: Gilbert, Jack A., MOST | National Natural Science Foundation of China, MOST | National Key Research and Development Program of China

المصدر: mSystems ; volume 9, issue 3 ; ISSN 2379-5077

الوصف: Engineering microbial hosts to synthesize pyruvate derivatives depends on blocking pyruvate oxidation, thereby causing severe growth defects in aerobic glucose-based bioprocesses. To decouple pyruvate metabolism from cell growth to improve pyruvate availability, a genome-scale metabolic model combined with constraint-based flux balance analysis, geometric flux balance analysis, and flux variable analysis was used to identify genetic targets for strain design. Using translation elements from a ~3,000 cistronic library to modulate fxpK expression in a bicistronic cassette, a bifido shunt pathway was introduced to generate three molecules of non-pyruvate-derived acetyl-CoA from one molecule of glucose, bypassing pyruvate oxidation and carbon dioxide generation. The dynamic control of flux distribution by T7 RNAP-mediated synthetic small RNA decoupled pyruvate catabolism from cell growth. Adaptive laboratory evolution and multi-omics analysis revealed that a mutated isocitrate dehydrogenase functioned as a metabolic switch to activate the glyoxylate shunt as the only C4 anaplerotic pathway to generate malate from two molecules of acetyl-CoA input and bypass two decarboxylation reactions in the tricarboxylic acid cycle. A chassis strain for pyruvate derivative synthesis was constructed to reduce carbon loss by using the glyoxylate shunt as the only C4 anaplerotic pathway and the bifido shunt as a non-pyruvate-derived acetyl-CoA synthetic pathway and produced 22.46, 27.62, and 6.28 g/L of l -leucine, l -alanine, and l -valine by a controlled small RNA switch, respectively. Our study establishes a novel metabolic pattern of glucose-grown bacteria to minimize carbon loss under aerobic conditions and provides valuable insights into cell design for manufacturing pyruvate-derived products. IMPORTANCE Bio-manufacturing from biomass-derived carbon sources using microbes as a cell factory provides an eco-friendly alternative to petrochemical-based processes. Pyruvate serves as a crucial building block for the ...

الإتاحة: https://doi.org/10.1128/msystems.00839-23Test

المؤلفون: Li, Zhongcai, Liu, Qian, Sun, Jiahui, Sun, Jianjian, Li, Mingjie, Zhang, Yun, Deng, Aihua, Liu, Shuwen, Wen, Tingyi

المساهمون: National Natural Science Foundation of China, Youth Innovation Promotion Association of the Chinese Academy of Sciences, Innovation Academy for Green Manufacture, Chinese Academy of Sciences

المصدر: Biotechnology for Biofuels and Bioproducts ; volume 16, issue 1 ; ISSN 2731-3654

مصطلحات موضوعية: Management, Monitoring, Policy and Law, Energy (miscellaneous), Applied Microbiology and Biotechnology, Renewable Energy, Sustainability and the Environment, Biotechnology

الوصف: Background l -Methionine is the only bulk amino acid that has not been industrially produced by the fermentation method. Due to highly complex and strictly regulated biosynthesis, the development of microbial strains for high-level l -methionine production has remained challenging in recent years. Results By strengthening the l -methionine terminal synthetic module via site-directed mutation of l -homoserine O-succinyltransferase (MetA) and overexpression of metA fbr , metC , and yjeH , l- methionine production was increased to 1.93 g/L in shake flask fermentation. Deletion of the pykA and pykF genes further improved l- methionine production to 2.51 g/L in shake flask fermentation. Computer simulation and auxotrophic experiments verified that during the synthesis of l- methionine, equimolar amounts of l- isoleucine were accumulated via the elimination reaction of cystathionine γ-synthetase MetB due to the insufficient supply of l- cysteine. To increase the supply of l- cysteine, the l- cysteine synthetic module was strengthened by overexpression of cysE fbr , serA fbr , and cysDN , which further increased the production of l- methionine by 52.9% and significantly reduced the accumulation of the byproduct l- isoleucine by 29.1%. After optimizing the addition of ammonium thiosulfate, the final metabolically engineered strain MET17 produced 21.28 g/L l -methionine in 64 h with glucose as the carbon source in a 5 L fermenter, representing the highest l -methionine titer reported to date. Conclusions In this study, a high-efficiency strain for l -methionine production was derived from wild-type Escherichia coli W3110 by rational metabolic engineering strategies, providing an efficient platform for the industrial production of l -methionine.

الإتاحة: https://doi.org/10.1186/s13068-023-02347-7Test

المؤلفون: Deng, Aihua, Wang, Tiantian, Wang, Junyue, Li, Lai, Wang, Xueliang, Liu, Li, Wen, Tingyi

المصدر: Science of The Total Environment ; volume 886, page 163952 ; ISSN 0048-9697

مصطلحات موضوعية: Pollution, Waste Management and Disposal, Environmental Chemistry, Environmental Engineering

الإتاحة: https://doi.org/10.1016/j.scitotenv.2023.163952Test
https://api.elsevier.com/content/article/PII:S0048969723025731?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S0048969723025731?httpAccept=text/plainTest

المؤلفون: Luo, Feng, Wen, Tingyi, Wu, Jiarui, Qin, Hao qing, Wu, Xiaoqiang

المساهمون: Natural Science Foundation of Sichuan Province, Material Corrosion and Protection Key Laboratory of Sichuan Province

المصدر: New Journal of Chemistry ; volume 48, issue 14, page 6180-6187 ; ISSN 1144-0546 1369-9261

الوصف: By electrodepositing Pt/NiCo nanocatalysts on l -shaped glassy carbon substrates, high methanol oxidation reaction (MOR) durability was achieved.

الإتاحة: https://doi.org/10.1039/d4nj00015cTest
http://pubs.rsc.org/en/content/articlepdf/2024/NJ/D4NJ00015CTest

المؤلفون: Deng, Aihua, Qiu, Qidi, Sun, Qinyun, Chen, Zhenxiang, Wang, Junyue, Zhang, Yu, Liu, Shuwen, Wen, Tingyi

المساهمون: the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, the Innovation Academy for Green Manufacture, Chinese Academy of Sciences

المصدر: Biotechnology for Biofuels and Bioproducts ; volume 15, issue 1 ; ISSN 2731-3654

مصطلحات موضوعية: Management, Monitoring, Policy and Law, Energy (miscellaneous), Applied Microbiology and Biotechnology, Renewable Energy, Sustainability and the Environment, Biotechnology

الوصف: Background Purine nucleosides play essential roles in cellular physiological processes and have a wide range of applications in the fields of antitumor/antiviral drugs and food. However, microbial overproduction of purine nucleosides by de novo metabolic engineering remains a great challenge due to their strict and complex regulatory machinery involved in biosynthetic pathways. Results In this study, we designed an in silico-guided strategy for overproducing purine nucleosides based on a genome-scale metabolic network model in Bacillus subtilis . The metabolic flux was analyzed to predict two key backflow nodes, Drm (purine nucleotides toward PPP) and YwjH (PPP–EMP), to resolve the competitive relationship between biomass and purine nucleotide synthesis. In terms of the purine synthesis pathway, the first backflow node Drm was inactivated to block the degradation of purine nucleotides, which greatly increased the inosine production to 13.98–14.47 g/L without affecting cell growth. Furthermore, releasing feedback inhibition of the purine operon by promoter replacement enhanced the accumulation of purine nucleotides. In terms of the central carbon metabolic pathways, the deletion of the second backflow node YwjH and overexpression of Zwf were combined to increase inosine production to 22.01 ± 1.18 g/L by enhancing the metabolic flow of PPP. By switching on the flux node of the glucose-6-phosphate to PPP or EMP, the final inosine engineered strain produced up to 25.81 ± 1.23 g/L inosine by a pgi -based metabolic switch with a yield of 0.126 mol/mol glucose, a productivity of 0.358 g/L/h and a synthesis rate of 0.088 mmol/gDW/h, representing the highest yield in de novo engineered inosine bacteria. Under the guidance of this in silico - designed strategy, a general chassis bacterium was generated, for the first time, to efficiently synthesize inosine, adenosine, guanosine, IMP and GMP, which provides sufficient precursors for the synthesis of various purine intermediates. Conclusions Our study reveals that ...

الإتاحة: https://doi.org/10.1186/s13068-022-02179-xTest

المؤلفون: Xiao, Haihan, Xiao, Haijuan, Zhang, Yun, Guo, Lingyun, Dou, Zhenzhen, Liu, Linlin, Zhu, Liang, Feng, Wenya, Liu, Bing, Hu, Bing, Chen, Tianming, Liu, Gang, Wen, Tingyi

المساهمون: National Science and Technology Major Project

المصدر: Frontiers in Immunology ; volume 13 ; ISSN 1664-3224

مصطلحات موضوعية: Immunology, Immunology and Allergy

الوصف: Bacterial meningitis (BM) is a common life-threatening infection in children that occurs in the central nervous system (CNS). The cytologic examination of cerebrospinal fluid (CSF) is a key parameter in the diagnosis of BM, but the heterogeneity of cells in the CSF has not been elucidated, which limits the current understanding of BM neuroinflammation. In this study, CSF samples were collected from a number of BM patients who were in different stages of disease progression. Single-cell RNA-sequencing (scRNA-seq), with additional bulk transcriptome sequencing, was conducted to decipher the characteristics of CSF cells in BM progression. A total of 18 immune cell clusters in CSF were identified, including two neutrophils, two monocytes, one macrophage, four myeloid dendritic cells, five T cells, one natural killer cell, one B cell, one plasmacytoid dendritic cell, and one plasma cell subtype. Their population profiles and dynamics in the initial onset, remission, and recovery stages during BM progression were also characterized, which showed decreased proportions of myeloid cells and increased proportions of lymphoid cells with disease progression. One novel neutrophil subtype, FFAR2 + TNFAIP6 + neutrophils, and one novel monocyte subtype, THBS1 + IL1B + monocytes, were discovered, and their quantity changes positively correlated with the intensity of the inflammatory response in the CSF during BM. In addition, the CSF of BM patients with unsatisfactory therapeutic responses presented with different cell heterogeneity compared to the CSF of BM patients with satisfactory therapeutic responses, and their CSF featured altered intercellular communications and increased proportions of type II myeloid dendritic cells and plasmacytoid dendritic cells. Moreover, the bulk transcriptome profiles of autologous CSF cells and peripheral blood leukocytes of BM patients showed that the immune cells in these two physiological compartments exhibited distinct immune responses under different onset conditions. In particular, the CSF ...

الإتاحة: https://doi.org/10.3389/fimmu.2022.872832Test

المؤلفون: Wang, Xueliang, Zhang, Yun, Wen, Tingyi

المصدر: Chinese Science Bulletin ; volume 66, issue 19, page 2393-2404 ; ISSN 0023-074X

مصطلحات موضوعية: Multidisciplinary

الإتاحة: https://doi.org/10.1360/tb-2020-1468Test

المؤلفون: Deng, Aihua, Sun, Zhaopeng, Wang, Tiantian, Cui, Di, Li, Lai, Liu, Shuwen, Huang, Fei, Wen, Tingyi

المساهمون: National Natural Science Foundation of China

المصدر: Frontiers in Microbiology ; volume 12 ; ISSN 1664-302X

مصطلحات موضوعية: Microbiology (medical), Microbiology

الوصف: Multiplex engineering at the scale of whole genomes has become increasingly important for synthetic biology and biotechnology applications. Although several methods have been reported for engineering microbe genomes, their use is limited by their complex procedures using multi-cycle transformations. Natural transformation, involving in species evolution by horizontal gene transfer in many organisms, indicates its potential as a genetic tool. Here, we aimed to develop simultaneous multiplex genome engineering (SMGE) for the simple, rapid, and efficient design of bacterial genomes via one-step of natural transformation in Bacillus subtilis . The transformed DNA, competency factors, and recombinases were adapted to improved co-editing frequencies above 27-fold. Single to octuplet variants with genetic diversity were simultaneously generated using all-in-one vectors harboring multi-gene cassettes. To demonstrate its potential application, the tyrosine biosynthesis pathway was further optimized for producing commercially important resveratrol by high-throughput screening of variant pool in B. subtilis . SMGE represents an accelerated evolution platform that generates diverse multiplex mutations for large-scale genetic engineering and synthetic biology in B. subtilis .

الإتاحة: https://doi.org/10.3389/fmicb.2021.714449Test

المؤلفون: Liu, Shuwen, Xiao, Haihan, Zhang, Fangfang, Lu, Zheng, Zhang, Yun, Deng, Aihua, Li, Zhongcai, Yang, Cui, Wen, Tingyi

المساهمون: Strategic Priority Research Program of the Chinese Academy of Sciences, National Natural Science Foundation of China, Youth Innovation Promotion Association of the Chinese Academy of Sciences

المصدر: Biotechnology for Biofuels ; volume 12, issue 1 ; ISSN 1754-6834

مصطلحات موضوعية: Management, Monitoring, Policy and Law, General Energy, Renewable Energy, Sustainability and the Environment, Applied Microbiology and Biotechnology, Biotechnology

الإتاحة: https://doi.org/10.1186/s13068-019-1520-xTest

المؤلفون: Jiang,Xiaodan, Deng,Aihua, Yang,Jiarui, Bai,Hua, Yang,Zhao, Wu,Jie, Lv,Huibin, Li,Xuemin, Wen,Tingyi

مصطلحات موضوعية: Infection and Drug Resistance

الوصف: Xiaodan Jiang,1,2,* Aihua Deng,3,* Jiarui Yang,1,2,* Hua Bai,3 Zhao Yang,3 Jie Wu,3 Huibin Lv,1,2 Xuemin Li,1,2 Tingyi Wen3,4 1Department of Ophthalmology, Peking University Third Hospital, Beijing 100191, China; 2Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing 100191, China; 3CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; 4Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China *These authors contributed equally to this work Objective: To explore the composition of the ocular microbiome in normal subjects and patients with Meibomian gland dysfunction (MGD). Subjects and methods: Seventy subjects (140 eyes) were enrolled in our study. Signs of dry eye were evaluated and bacterial species in the conjunctival sac (CS) and Meibomian gland (MG) secretions were then identified by 16S rRNA gene sequencing. Additionally, 17 subjects (34 eyes) were further evaluated to determine differences in the microbiomes in the surface and deep layers of MG using a segmental secretion analysis. Results: The positive bacterial isolation rate was markedly higher in MG secretions than in the CS. The bacterial composition of the control and mild group was simple, whereas the composition of bacteria was more complex as the severity of MGD increased. The positive bacterial isolation rate and number of bacterial types were significantly higher in the severe MGD group than those in the control, mild and moderate MGD groups. Corynebacterium macginleyi was only detected in the severe MGD group, with an isolation rate of up to 26.3%. Furthermore, a new grading system for bacterial severity of MGD was proposed and the severity of MGD appeared to be positively correlated with a higher grade of bacterial severity. The segmental secretion analysis showed severe MGD had a significantly higher incidence of bacterial discordance rate. Conclusion: The severity of MGD was ...

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العلاقة: https://www.dovepress.com/pathogens-in-the-meibomian-gland-and-conjunctival-sac-microbiome-of-no-peer-reviewed-fulltext-article-IDRTest

الإتاحة: https://doi.org/10.2147/IDR.S162135Test
https://www.dovepress.com/pathogens-in-the-meibomian-gland-and-conjunctival-sac-microbiome-of-no-peer-reviewed-fulltext-article-IDRTest