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Engineering and finetuning expression of SerC for balanced metabolic flux in vitamin B6 production

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Synthetic and Systems Biotechnology 2024年第2期9卷 388-398页

作者： Kai Chen Linxia Liu Jinlong Li Zhizhong Tian Hongxing Jin Dawei Zhang School of Chemical Engineering and Technology Hebei University of TechnologyTianjinChina tianjin Institute of industrial Biotechnology Chinese Academy of SciencesTianjinChina National Center of Technology Innovation for Synthetic biology TianjinChina key laboratory of Engineering biology for Low-Carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjinChina University of Chinese Academy of Sciences BeijingChina

Vitamin B6 plays a crucial role in cellular metabolism and stress response,making it an essential component for growth in all known ***,achieving efficient biosynthesis of vitamin B6 faces the challenge of maintaining a balanced distribution of metabolic flux between growth and *** this study,our focus is on addressing this challenge through the engineering of phosphoserine aminotransferase(SerC)to resolve its redundancy and *** enzyme SerC was semi-designed and screened based on sequences and predicted kcat values,*** and heterologous proteins showing potential were then fine-tuned to optimize the production of vitamin *** resulting strain enhances the production of vitamin B6,indicating that different fluxes are distributed to the biosynthesis pathway of serine and vitamin *** study presents a promising strategy to address the challenge posed by multifunctional enzymes,with significant implications for enhancing biochemical production through engineering processes.

关键词： Vitamin B6 Phosphoserine aminotransferase SerC Protein engineering Multifunctional enzymes Metabolic flux distribution

ECMpy 2.0:A Python package for automated construction and analysis of enzyme-constrained models

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Synthetic and Systems Biotechnology 2024年第3期9卷 494-502页

作者： Zhitao Mao Jinhui Niu Jianxiao Zhao Yuanyuan Huang Ke Wu Liyuan Yun Jirun Guan Qianqian Yuan Xiaoping Liao Zhiwen Wang Hongwu Ma Biodesign Center Key Laboratory of Engineering Biology for Low-carbon ManufacturingTianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin300308China National Center of Technology Innovation for Synthetic biology Tianjin300308China Frontier Science Center for Synthetic biology and key laboratory of Systems Bioengineering(Ministry of Education) Tianjin UniversityTianjin300072China College of Biotechnology Tianjin University of Science and TechnologyTianjin300457China Institute of Biopharmaceutical and Health Engineering Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhenChina tianjin Agricultural College Tianjin300384China Haihe laboratory of Synthetic biology Tianjin300308China

Genome-scale metabolic models(GEMs)have been widely employed to predict microorganism ***,GEMs only consider stoichiometric constraints,leading to a linear increase in simulated growth and product yields as substrate uptake rates *** divergence from experimental measurements prompted the creation of enzyme-constrained models(ecModels)for various species,successfully enhancing chemical *** upon studies that allocate macromolecule resources,we developed a Python-based workflow(ECMpy)that constructs an enzyme-constrained *** involves directly imposing an enzyme amount constraint in GEM and accounting for protein subunit composition in ***,this procedure de-mands manual collection of enzyme kinetic parameter information and subunit composition details,making it rather *** this work,we’ve enhanced the ECMpy toolbox to version 2.0,broadening its scope to automatically generate ecGEMs for a wider array of *** 2.0 automates the retrieval of enzyme kinetic parameters and employs machine learning for predicting these parameters,which significantly enhances parameter ***,ECMpy 2.0 introduces common analytical and visualization features for ecModels,rendering computational results more user ***,ECMpy 2.0 seamlessly integrates three published algorithms that exploit ecModels to uncover potential targets for metabolic *** 2.0 is available at https://***/tibbdc/ECMpy or as a pip package(https://***/project/ECMpy/).

关键词： Enzyme-constrained model Python package Automated construction Multiple analysis functions

A new era for paclitaxel biosynthesis is coming

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Molecular Plant 2024年第3期17卷 370-371页

作者： Xiaonan Liu Xiaoxi Zhu Jian Cheng Huifeng Jiang key laboratory of Engineering biology for Low-carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China National Center of Technology Innovation for Synthetic biology Tianjin 300308China

Paclitaxel(Taxol)stands out as a tetracyclic diterpenoid natural product derived from the endangered plant *** as a pivotal broad-spectrum anticancer drug,it has garnered widespread attention due to its low yield,intricate structure,unique anticancer mechanism,and remarkable efficacy(Tong et al.,2021).Although chemists achieved the total synthesis of paclitaxel 30 years ago,after decades of research,the natural biosynthetic pathway for its production remains an enigma(Ajikumar et al.,2010;Malci et al.,2023).A recent breakthrough,published in Molecular Plant by Alisdair ***'s team,unveils a minimal gene set of 18 genes required for paclitaxel biosynthesis(Zhang et al.,2023),representing a significant mark toward unraveling the entire biosynthetic pathway and enhancing paclitaxel production efficiency.

关键词： breakthrough representing synthesis

Multivariate modular metabolic engineering and medium optimization for vitamin B_(12)production by Escherichia coli

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Synthetic and Systems Biotechnology 2024年第3期9卷 453-461页

作者： Feitao Chen Huan Fang Jianghua Zhao Pingtao Jiang Huina Dong Ying Zhao Huiying Wang Tongcun Zhang Dawei Zhang College of Biotechnology Tianjin University of Science&TechnologyTianjin300457China tianjin Institute of industrial Biotechnology Chinese Academy of SciencesTianjin300308China University of Chinese Academy of Science Beijing100049China key laboratory of Engineering biology for Low-Carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China National Center of Technology Innovation for Synthetic biology Tianjin300308China

Vitamin B_(12)is a complex compound synthesized by *** industrial production of vitamin B_(12)relies on specific microbial fermentation *** has been utilized as a host for the de novo biosynthesis of vitamin B_(12),incorporating approximately 30 heterologous ***,a metabolic imbalance in the intricate pathway significantly limits vitamin B_(12)*** this study,we employed multivariate modular metabolic engineering to enhance vitamin B_(12)production in *** by manipulating two modules comprising a total of 10 genes within the vitamin B_(12)biosynthetic *** two modules were integrated into the chromosome of a chassis cell,regulated by T7,J23119,and J23106 promoters to achieve combinatorial pathway *** highest vitamin B_(12)titer was attained by engineering the two modules controlled by J23119 and T7 *** inclusion of yeast powder to the fermentation medium increased the vitamin B_(12)titer to 1.52 mg/*** enhancement was attributed to the effect of yeast powder on elevating the oxygen transfer rate and augmenting the strain’s isopropyl-β-D-1-thiogalactopyranoside(IPTG)***,vitamin B_(12)titer of 2.89 mg/L was achieved through scaled-up fermentation in a 5-liter *** strategies reported herein will expedite the development of industry-scale vitamin B_(12)production utilizing ***.

关键词： Vitamin B_(12) Multivariate modular metabolic engineering E.coli Organic nitrogen sources Fed-batch fermentation

Cross-linkedα-amylase aggregates on Fe3O4 magnetic nanoparticles modified with polydopamine/polyethyleneimine for efficient hydrolysis of starch

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Particuology 2024年第7期90卷 98-105页

作者： Jiandong Cui Xiuming Tang Qingqing Ma Yuyan Chang Qunli Zhang Shiru Jia State key laboratory of Food Nutrition and Safety Laboratory of Industrial Fermentation MicrobiologyMinistry of EducationTianjin University of Science and TechnologyTianjin 300457China key laboratory of Biomass Chemical Engineering of Ministry of Education Zhejiang UniversityHangzhou 310027China

In this workα-amylase was immobilized on magnetic Fe3O4 nanoparticles with polyethylenimine(PEI)/polydopamine(PDA)coating or 3-aminopropyl triethoxysilane(APTES)for the first time via adsorption–precipitation–*** with the freeα-amylase,the resultant magnetic cross-linkedα-amylase aggregates(PEI/PDA-M-CLEAs and N-M-CLEAs)exhibited excellent thermal and storage stability as well as pH *** storage at 25°C for 60 days,freeα-amylase only retained 60%of its initial activity,while PEI/PDA-M-CLEAs and N-M-CLEAs retained 80%and 78%of their initial activities,***,N-M-CLEAs and PEI/PDA-M-CLEAs showed good *** 6 repeated uses,PEI/PDA-M-CLEAs and N-M-CLEAs still maintained 65%and 62%of their initial activities,***,PEI/PDA-M-CLEAs and N-M-CLEAs exhibited higher starch hydrolysis efficiency than freeα-*** maximum dextrose equivalent(DE)values of starch hydrolysis by PEI/PDA-M-CLEAs and N-M-CLEAs reached 29.24%and 28.79%within 90 min,***,the maximum DE values of starch hydrolysis by the freeα-amylase was only 27.89%even in 150 *** magnetic cross-linkedα-amylase aggregates could be introduced as effective biocatalyst for industrial applications in production of maltose syrups.

关键词： α-amylase Magnetic nanoparticles Functional modification Magnetic cross-linked enzyme aggregates Hydrolysis of starch

Cyclization mechanism of monoterpenes catalyzed by monoterpene synthases in dipterocarpaceae

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Synthetic and Systems Biotechnology 2024年第1期9卷 11-18页

作者： Xiaoyun Lu Jie Bai Zunzhe Tian Congyu Li Nida Ahmed Xiaonan Liu Jian Cheng Lina Lu Jing Cai Huifeng Jiang Wen Wang School of Ecology and Environment Northwestern Polytechnical UniversityXi’anShanxi710072China key laboratory of Engineering biology for Low-Carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin300308China

Monoterpenoids are typically present in the secretory tissues of higher plants,and their biosynthesis is catalyzed by the action of monoterpene synthases(MTSs).However,the knowledge about these enzymes is restricted in a few plant *** are responsible for the complex cyclization of monoterpene precursors,resulting in the production of diverse monoterpene *** enzymatic reactions are considered exceptionally complex in ***,it is crucial to understand the catalytic mechanism of MTSs to elucidate their ability to produce diverse or specific monoterpenoid *** our study,we analyzed thirteen genomes of Dipterocarpaceae and identified 38 MTSs that generate a variety of monoterpene *** focusing on four MTSs with different product spectra and analyzing the formation mechanism of acyclic,monocyclic and bicyclic products in MTSs,we observed that even a single amino acid mutation can change the specificity and diversity of MTS products,which is due to the synergistic effect between the shape of the active cavity and the stabilization of carbon-positive intermediates that the mutation ***,residues N340,I448,and phosphoric acid groups were found to be significant contributors to the stabilization of intermediate terpinyl and pinene *** in these residues,either directly or indirectly,can impact the synthesis of single monoterpenes or their *** revealing the role of key residues in the catalytic process and establishing the interaction model between specific residues and complex monoterpenes in MTSs,it will be possible to reasonably design and engineer different catalytic activities into existing MTSs,laying a foundation for the artificial design and industrial application of MTSs.

关键词： Cyclization Monoterpene synthases Intermediate stabilization

A hybrid RNA-protein biosensor for high-throughput screening of adenosylcobalamin biosynthesis

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Synthetic and Systems Biotechnology 2024年第3期9卷 513-521页

作者： Xia Yang Huiying Wang Dongqin Ding Huan Fang Huina Dong Dawei Zhang College of Biological and Pharmaceutical Sciences China Three Gorges UniversityYichangHubei443002China tianjin Institute of industrial Biotechnology Chinese Academy of SciencesTianjin300308China key laboratory of Engineering biology for Low-Carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin300308China University of Chinese Academy of Sciences Beijing100049China

Genetically encoded circuits have been successfully utilized to assess and characterize target variants with desirable traits from large mutant *** is an essential coenzyme that is required in many intracellular physiological reactions and is widely used in the pharmaceutical and food ***-throughput screening techniques capable of detecting adenosylcobalamin productivity and selecting superior adenosylcobalamin biosynthesis strains are critical for the creation of an effective microbial cell factory for the production of adenosylcobalamin at an industrial *** this study,we developed an RNA-protein hybrid biosensor whose input part was an endogenous RNA riboswitch to specifically respond to adenosylcobalamin,the inverter part was an orthogonal transcriptional repressor to obtain signal inversion,and the output part was a fluorescent protein to be easily *** hybrid biosensor could specifically and positively correlate adenosylcobalamin concentrations to green fluorescent protein expression levels in *** study also improved the operating concentration and dynamic range of the hybrid biosensor by systematic *** individual cell harboring the hybrid biosensor presented over 20-fold higher fluorescence intensity than the negative ***,using such a biosensor combined with fluorescence-activated cell sorting,we established a high-throughput screening platform for screening adenosylcobalamin *** study demonstrates that this platform has significant potential to quickly isolate high-productive strains to meet industrial demand and that the framework is acceptable for various metabolites.

关键词： Adenosylcobalamin Genetically encoded biosensor Riboswitch Transcriptional repressor High-throughput screening

Enhanced stability of nitrogen-doped carbon-supported palladium catalyst for oxidative carbonylation of phenol

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Chinese Journal of Chemical Engineering 2024年第1期65卷 19-28页

作者： Xiaojing Liu Ruohan Zhao Hao Zhao Zhimiao Wang Fang Li Wei Xue Yanji Wang Hebei Provincial key laboratory of Green Chemical Technology and High Efficient Energy Saving School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China tianjin key laboratory of Chemical Process Safety Tianjin 300130China Hebei industrial Technology Research Institute of Green Chemical Industry Huanghua 061100China

Enhancing the stability of supported noble metal catalysts emerges is a major challenge in both science and ***,a heterogeneous Pd catalyst(Pd/NCF)was prepared by supporting Pd ultrafine metal nanoparticles(NPs)on nitrogen-doped carbon;synthesized by using F127 as a stabilizer,as well as chitosan as a carbon and nitrogen *** Pd/NCF catalyst was efficient and recyclable for oxidative carbonylation of phenol to diphenyl carbonate,exhibiting higher stability than Pd/NC prepared without F127 *** hydrogen bond between chitosan(CTS)and F127 was enhanced by F127,which anchored the N in the free amino group,increasing the N content of the carbon material and ensuring that the support could provide sufficient N sites for the deposition of Pd *** process helped to improve metal *** increased metal-support interaction,which limits the leaching and coarsening of Pd NPs,improves the stability of the Pd/NCF ***,density functional theory calculations indicated that pyridine N stabilized the Pd^(2+)species,significantly inhibiting the loss of Pd^(2+)in Pd/NCF during the reaction *** work provides a promising avenue towards enhancing the stability of nitrogen-doped carbon-supported metal catalysts.

关键词： Supported Pd catalyst N-doped carbon Amphiphilic triblock copolymer Pyridinic nitrogen Stability

Asymmetric reduction of conjugated C=C bonds by immobilized fusion of old yellow enzyme and glucose dehydrogenase

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Green Synthesis and Catalysis 2024年第2期5卷 80-87页

作者： Yongxing Li Pengqian Luan Lele Dong Jianqiao Liu Luying Jiang Jing Bai Fufeng Liu Yanjun Jiang School of Chemical Engineering and Technology Hebei University of TechnologyTianjin 300130China College of Food Science and biology Hebei University of Science&Technology26 Yuxiang StreetYuhua DistrictShijiazhuang 050018China key laboratory of industrial Fermentation microbiology of Ministry of Education Tianjin Key Laboratory of Industrial MicrobiologyCollege of BiotechnologyTianjin University of Science&TechnologyTianjin 300457China

Asymmetric reduction of the conjugated C=C bonds by the old yellow enzymes(OYEs)presents a promising field in the synthesis of chiral ***,few natural OYEs have been applied in large-scale applications due to the requirement of costly NADPH and low operational ***,a stable and efficient fusion of YqjM from Bacillus subtilis and glucose dehydrogenase(GDH)from Bacillus megaterium was constructed to stereoselectively reduce the conjugated C=C bonds in a self-sufficient continuous *** effects of the enzyme order and different linkers on the fusions were investigated by structural analysis and all-atom molecular dynamics *** best fusion YqjM_G_GDH gave 98% conversion of 100 mmol/L 2-methylcyclopentenone with an excellent ee value(>99%)in 3 h,while the mixture of individual enzymes only obtained 68% conversion after more than 8 *** improved substrate conversion of YqjM_G_GDH fusion was probably attributed to the increased flexibility of each fused enzyme and the shortening of the diffusion distance of NADPH regenerated.A one-pot process was designed to purify and immobilize the fusion on the Ni2t-nitrilotriacetic acid functionalized magnetic mesoporous silica *** resulting immobilized biocatalyst not only catalyzed the asymmetric reduction of various α,β-unsaturated ketones(20 mmol/L)continuously with only 50μmol/L NADPt to initiate the whole process,but also retained more than 82%of the initial activity after seven cycles,serving as a good candidate for the industrial applications.

关键词： Enzyme fusion Old yellowenzymes Asymmetricreduction C=C bond Cofactor regeneration Immobilization