PROCESS BIOCHEMISTRY
·
2024
·
IF 3.7
Shaoyang Zhang,Guorong Zhu,Zhixiang Pan,Yi Wei,Zuoming Nie,Qing Sheng,Zhongyi Yang
L-threo-methylsulonylphenylserine (L-threo-MSPS) is a crucial intermediate in florphenicol and thiamphenicol synthesis. L-threo-MSPS can be synthesized from L-threonine and p-methylsulfonylbenzaldehyde (p-MSBA) chiral selectively under the catalyse of L-threonine transaldolase . However, the byproduct acetaldehyde formed during the reaction process severely hinders the biosynthesis of high-quality L-threo-MSPS. The accumulated acetaldehyde reacts with L-thero-MSPS and L-threonine to form N-derivatives, and the activity of L-threonine transaldolase decreases to 14.10% even when the concentration of acetaldehyde is as low as 0.5 g/L. The acetaldehyde could be removed by aeration, and the removal efficiency is closely related to the aeration conditions, which was described by the volumetric oxygen transfer coefficient k L a in this paper. Regular aeration through pipes cannot provide enough aeration efficiency, and filters or sintered rods were used to increase the k L a value during the reaction. The residual concentration of acetaldehyde depended on the balance between the formation and removal speed of acetaldehyde. When the optimal enzyme concentration was applied and the k L a value of 5.5 min -1 , the L-threo-MSPS concentration reached 293.28 mM in a 1-L reaction, and the highest conversion reached 90.03%. The need of coenzyme NAD + was cut off in this method, and only one enzyme was applied. Consequently, the reaction was simpler and easier to control.
研究领域:
生物化学
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制药工程
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产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2023
·
IF 3.3
Wenjing Yan,Bin Liang,Wanhe Li,Hualin Huang,Deqiang Shi,Zhenming Chen,Zhongmin Li,Meihua Yu,Guangtao Wei,Kai Huang
The formation of vaterite is well known to be influenced by many low molecular weight additives. In this study, Density functional theory calculations was employed to study the effect of biological material lysine(Lys), aspartic acid(Asp), threonine(Thr) and glycine(Gly) on the formation of vaterite CaCO 3 . The interaction energies between Gly and CaCO 3 (110) and (104) surfaces were −2.618 and −1.784 eV, respectively. With the molar ratio of Ca 2+ to Gly at 1.5, the reaction time of 11.5 min, the pH value of 7.5, the crystalline product of the reaction was almost monodisperse spherical vaterite in Ca(OH) 2 -Gly-CO 2 reaction system. The obtained products were characterized by the XRD, RAM, SEM, TEM, and FT-IR. The results showed that the increase of Gly concentration inhibited the nucleation and the growth of calcite. Lys, Asp, Thr and Gly were employed as stabilizers for controlling particles, the crystalline product of the reaction was almost monodisperse vaterite CaCO 3 . Its surface chemistry can be explored using this mechanism analysis. The methods are expected to be a reference for industrial production process.
研究领域:
材料科学
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生物化学
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2025
·
IF 9
Xin Jin,Sumeng Wang,Yaping Gao,Qingsheng Qi,Quanfeng Liang
Background The industrial production of L-threonine faces challenges because of high production costs, especially those of substrates, meaning new production methods are needed. Methods Fur, a new global transcription factor related to L-threonine biosynthesis, was discovered in this study. Multidimensional regulation combined with global transcriptional machinery engineering was used to modify an Escherichia coli strain. Results: The most efficient mutant showed high titer (154.2 g/L), productivity (2.14 g/L/h), and yield (0.76 g/g) of L-threonine production. These three parameters indicated that these engineering strategies were economically feasible for developing high L-threonine-producing strains. We integrated the sucrose utilization gene cluster into the genome to further reduce the production cost of L-threonine. Using untreated cane molasses as the substrate, L-threonine was successfully produced with a titer of 92.46 g/L and a cost reduction of 48 %. Conclusion This research offers advantages for industrial scalability, and the resulting engineered bacterium holds significant industrial application potential.
研究领域:
生物工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2018
·
IF 3.767
Shuyan Zhao,Jie Guo,Wanxin Li,Hongchong Guo,Bo You
A novel cobalt aluminate (CoAl 2 O 4 ) nanopigments with bright blue color and good dispersibility was fabricated via a coprecipitation process of threonine. Threonin acts as coordination and structure-directing reagents for the nucleation and assembly of hydroxide precursor, limitation of the CoAl 2 O 4 nanoparticle growth during calcination process, and fine-tuning the molar ratio of Co/Al in final products. The products were characterized with XRD , FESEM, TEM , FTIR , DLS, EDX, ICP-AES and UV-vis. The particle size, colorimetric values and printing ink of CoAl 2 O 4 nanopigments with different amount of threonine and without threonine were investigated. The study exhibited that the CoAl 2 O 4 nanopigments with 0.1–0.2 mol/L threonine showed a smaller size of 10–20 nm, better dispersion and color property than other test samples. The coloration mechanism of the CoAl 2 O 4 nanopigments is also discussed.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 28
·期 4
·4262-4275
·
IF 3.056
Li Chao,Luo Miaomiao,Zhou Shihua,He Hanyue,Cao Jiashun,Luo Jingyang
l -Threonine and three kinds of conductive polymers were applied for anode modification in microbial fuel cells (MFCs) for decolorization of Congo red with simultaneous electricity generation. The description of modified anodes with FTIR, surface contact angle, and CV analysis showed that the anode surface was successfully grafted with functional groups, with improving wettability, as well as the increasing specific surface area and electrochemical activity. For l -threonine modification, the highest decolorization rate of 97% of the MFC, and meanwhile, the maximum current density of 155.8 mA/m 2 , was obtained at the modified concentration of 400 mg/L. For conductive polymer modifications, the poly (aniline-1,8-diaminonaphthalene) (short for PANDAN) owned the highest performance, with the current density 185 mA/m 2 , and the decolorization rate was 97%. Compared with l -threonine, the modifications by conductive polymers were more suitable for MFC decolorization due to their functional groups and unique conductivity. In addition, high-throughput sequencing analysis was conducted for the conductive polymers modified anodes to reveal their bioelectrochemical mechanisms.
研究领域:
环境科学
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生物化学工程
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产品关联
DOI
PubMed
高影响因子
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2024
·
IF 2.5
He Wang,Haidu Yuan,Jianhao Zhang,Wenjing Yan
Bacterial infections are becoming a significant threat to global human health due to the growing prevalence of biofilm-related infections and the rise in antibiotic resistance. D/ l -cysteine functionalized chiral gold nanoparticles (D/P-Au NPs or L/P-Au NPs) have demonstrated a potent antibacterial effect against E. coli , while the mechanism remains to be elucidated through additional research. Threonine deaminase (TD) is a crucial enzyme involved in branched-chain amino acid (BCAA) biosynthesis in E. coli and is involved in cysteine's antimicrobial effects. This study investigated the interaction between chiral Au NPs (D/P-Au NPs or L/P-Au NPs) and TD as well as its effect on enzyme activity. It demonstrates that chiral Au NPs interact with TD through hydrophobic forces, forming a ground state complex that induces changes in the secondary structure of TD and reduces enzyme activity in a concentration-dependent manner. We found that the exogenous supplementation of isoleucine and valine (2 mg/mL) significantly reduced the antibacterial activity of chiral Au NPs, especially for L/P-Au NPs. The proteomics results indicate that the expression of ilvA and ilvB was down-regulated after L/P-Au NPs treatment, which would interfere with the synthesis of BCAAs. These results demonstrate that chiral Au NPs cause cell death of E. coli partly due to inhibition of TD enzyme activity and the synthesis of branched-chain amino acids.
研究领域:
微生物学
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纳米生物学
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生物化学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
·
IF 5.7
Zhenqiang Zhao,Jiajia You,Xuanping Shi,Rongshuai Zhu,Fengyu Yang,Meijuan Xu,Minglong Shao,Rongzhen Zhang,Youxi Zhao,Zhiming Rao
Exploring effective remodeling strategies to further improve the productivity of high-yield strains is the goal of biomanufacturing. However, the lack of insight into host-specific metabolic networks prevents timely identification of useful engineering targets. Here, multidimensional engineering strategies were implemented to optimize the global metabolic network for improving l-threonine production. First, the metabolic bottleneck for l-threonine synthesis was eliminated by synergistic utilization of NADH and an enhanced ATP supply. Carbon fluxes were redistributed into the TCA cycle by rationally regulating the GltA activity. Subsequently, the stress global response regulator UspA was identified to enhance l-threonine production by a transcriptomic analysis. Then, l-threonine productivity was improved by enhancing the host’s stress resistance and releasing the inhibitory reaction of glucose utilization. Eventually, the l-threonine yield of THRH16 reached 170.3 g/L and 3.78 g/L/h in a 5 L bioreactor, which is the highest production index reported. This study provides rational guidance for increasing the productivity of other chemicals.
研究领域:
生物工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2020
·
IF 3.448
Wenlong Zheng,Kaitong Chen,Sai Fang,Xiuli Cheng,Gang Xu,Lirong Yang,Jianping Wu
A number of organic synthesis involve threonine aldolase (TA), a pyridoxal phosphate (PLP)-dependent enzyme. Although the addition of exogenous PLP is necessary for the reactions, it increases the cost and complicates the purification of the product. This work constructed a PLP self-sufficient biocatalysis system for TA, which included an improvement of the intracellular PLP level and co-immobilization of TA with PLP. Engineered strain BL-ST was constructed by introducing PLP synthase PdxS/T to Escherichia coli BL21(ED3). The intracellular PLP concentration of the strain increased approximately fivefold to 48.5 μmol/g DCW . l -TA, from Bacillus nealsonii ( Bn LTA), was co-expressed in the strain BL-ST with PdxS/T, resulting in the engineered strain BL- Bn LTA-ST. Compared with the control strain BL- Bn LTA (254.1 U/L), the enzyme activity of the strain BL- Bn LTA-ST reached 1518.4 U/L without the addition of exogenous PLP. An efficient co-immobilization system was then designed. The epoxy resin LX-1000HFA wrapped by polyethyleneimine (PEI) acted as a carrier to immobilize the crude enzyme solution of the strain BL- Bn LTA-ST mixed with an extra 100 μM of exogenous PLP, resulting in the catalyst HFA PEI - Bn LTA-STPLP 100. HFA PEI - Bn LTA-STPLP 100 exhibited a half-life of approximately 450 h, and the application of the catalyst in the continuous biosynthesis of 3-[4-(methylsulfonyl) phenyl] serine had more than 180 batch reactions (>60% conv ) without the extra addition of exogenous PLP. The excellent compatibility and stability of the system were further confirmed by other TAs. This work introduced a PLP self-sufficient biocatalysis system that can reduce the cost of PLP and contribute to the industrial application of TA. In addition, the system may also be applied in other PLP-dependent enzymes.
研究领域:
生物化学
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酶工程
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工业微生物学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Sai Fang,Zhe Wang,Lanxin Xiao,Yan Meng,Yixuan Lei,Tianxin Liang,Yuhuan Chen,Xiaoshu Zhou,Gang Xu,Lirong Yang,Wenlong Zheng,Jianping Wu
l -threonine aldolase (LTA) catalyzes the synthesis of β -hydroxy- α -amino acids, which are important chiral intermediates widely used in the fields of pharmaceuticals and pesticides. However, the limited thermostability of LTA hinders its industrial application. Furthermore, the trade-off between thermostability and activity presents a challenge in the thermostability engineering of this enzyme. This study proposes a strategy to regulate the rigidity of LTA's V-shaped subunit by modifying its opening and hinge regions, distant from the active center, aiming to mitigate the trade-off. With LTA from Bacillus nealsonii as targeted enzyme, a total of 25 residues in these two regions were investigated by directed evolution. Finally, mutant G85A/M207L/A12C was obtained, showing significantly enhanced thermostability with a 20 °C increase in T 50 60 to 66 °C, and specific activity elevated by 34 % at the optimum temperature. Molecular dynamics simulations showed that the newly formed hydrophobicity and hydrogen bonds improved the thermostability and boosted proton transfer efficiency. This work enhances the thermostability of LTA while preventing the loss of activity. It opens new avenues for the thermostability engineering of other industrially relevant enzymes with active center located at the interface of subunits or domains.
研究领域:
生物化学
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酶工程
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蛋白质工程
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DOI
PubMed
高影响因子
ACS Applied Nano Materials
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2024
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IF 5.3
Hang Su,Shuo Huang,Xin Gao,He Bai,Haopeng Zhang,Long Li,Lei Zhao,Hongyan Yue
Highly efficient recognition and detection of chiral molecules with similar structures are of great significance in the fields of medicine and biochemistry. In this study, strobili fibers of the plane tree were carbonized at high temperatures to prepare hollow chiral helical carbon tubes (HCT). Subsequently, l-threonine (l-Thr) was nanoassembled on the HCT surface (l-Thr@HCT) through hydrogen bonding and electrostatic interactions. Benefiting from the synergistic effect of conductive HCT with inherent chirality and l-Thr with abundant chiral sites, the electrode demonstrates a satisfied recognition efficiency of 3.20 for the cysteine (Cys) enantiomer. The l-Thr@HCT/GCE electrode exhibits a lower affinity toward l-Cys than d-Cys, thereby facilitating the diffusion of l-Cys to the electrode surface and exhibiting excellent selectivity for l-Cys. Under the optimal conditions, the electrode has a high sensitivity of 1.74 μA·mM–1 for l-Cys with a low detection limit of 8.58 μM (S/N = 3). Moreover, the electrode has good repeatability, reproducibility, and stability. This electrode will have a potential clinical application in chiral sensing.
研究领域:
生物医学工程
·
分析化学
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产品关联
DOI
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2016
·Vol. 358
·期 18
·2923-2928
·
IF 6.453
Peiyuan Yao,Yunfeng Cui,Shanshan Yu,Yuncheng Du,Jinhui Feng,Qiaqing Wu,Dunming Zhu
An efficient multi-enzyme cascade reaction for the synthesis of ( R )- or ( S )-2-hydroxybutyric acid [( R )- or ( S )-2-HB] from l -threonine was developed by using recombinant Escherichia coli cells expressing separately or co-expressing l -threonine deaminase from Escherichia coli K-12 ( ilvA ), formate dehydrogenase (FDH) from Candida boidinii and l -lactate dehydrogenase ( l -LDH) from Oryctolagus cuniculus or d -lactate dehydrogenase ( d -LDH) from Staphylococcus epidermidis ATCC 12228. Up to 750 mM of l -threonine were completely transformed to ( R )- or ( S )-2-HB in optically pure form (>99% ee ) with high isolated yields. This one-pot multi-enzyme transformation provides a new practical method for the synthesis of these important optically pure compounds.
研究领域:
生物化学
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合成生物学
·
代谢工程
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产品关联
DOI
高影响因子
FOOD AND BIOPRODUCTS PROCESSING
·
2023
·
IF 4.6
Yulu Du,Yue Wang,Tianyou Cui,Lianpeng Ge,Fan Yu,Mengqian Zhao,Qihang Xu,Mingjie Jin,Bo Chen,Xuwei Long
Biosurfactant surfactin has a high market value and broad application prospects in the food industry and various industrial fields. However, its production efficiency limits its suitability for real applications. In this study, a new Bacillus subtilis (sp.) 50499 strain was isolated from crude oil-contaminated soil and used to efficiently produce surfactin. The initial surfactin titer was 2.25 g/L after three days of fermentation. Adding 2 g/L of L -Leu significantly improved the titer to over 5.5 g/L after optimizing the culture medium at 37 °C. However, adding D -Leu had the opposite effect on surfactin production , and the surfactin titer dropped to below 0.2 g/L. Furthermore, the product of this strain was analyzed to confirm the identity of surfactin. The surfactin obtained in the present study reduced the surface tension of water to 28.6 mN/m at a critical micelle concentration of 20 mg/L. The emulsification index against n -hexane, corn , and crude oil was as high as over 90%. Hence, the present study provides a newly over-producing strain for surfactin production.
研究领域:
微生物学
·
生物技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）