Enhancement of α-ketoglutarate Production in Torulopsis glabrata: Redistribution of Carbon Flux from Pyruvate to α-ketoglutarate

Dandan Zhang,Nan Liang,Zhongping Shi,Liming Liu,Jian Chen,Guocheng Du 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.2

This manuscript aimed at increasing the production of α-ketoglutarate by the multi-vitamin auxotrophic yeast Torulpsis glabrata CCTCC M202019. The carbon flux was redistributed from pyruvate to α-ketoglutarate node by manipulating the specific activity of pyruvate dehydrogenase complex (PDH), pyruvate carboxylase (PC), pyruvate decarboxylase (PDC), and α-ketoglutarate dehydrogenase complex (KGDH). By proper increase of PDH, PC, and PDC activities, α-ketoglutarate in fermentation broth could be accumulated to the levels of 17.1 g/L, 21.6 g/L, and 31.2 g/L, respectively. In addition, decrease in the specific activity of KGDH also resulted in an enhanced α-ketoglutarate synthesis. With a proposed combinational enzymes regulation strategy, the highest α-ketoglutarate concentration of 37.7 g/L was achieved This manuscript aimed at increasing the production of α-ketoglutarate by the multi-vitamin auxotrophic yeast Torulpsis glabrata CCTCC M202019. The carbon flux was redistributed from pyruvate to α-ketoglutarate node by manipulating the specific activity of pyruvate dehydrogenase complex (PDH), pyruvate carboxylase (PC), pyruvate decarboxylase (PDC), and α-ketoglutarate dehydrogenase complex (KGDH). By proper increase of PDH, PC, and PDC activities, α-ketoglutarate in fermentation broth could be accumulated to the levels of 17.1 g/L, 21.6 g/L, and 31.2 g/L, respectively. In addition, decrease in the specific activity of KGDH also resulted in an enhanced α-ketoglutarate synthesis. With a proposed combinational enzymes regulation strategy, the highest α-ketoglutarate concentration of 37.7 g/L was achieved

Protein Associated with Adventitious Root Induction Analysis of Tree Peony (Paeonia suffruticosa Andr.) Plantlets In Vitro by Two-dimensional Electrophoresis and Mass Spectrometry

Dandan Zhang,Zheng Wang,Liyun Shi,Wenqian Shang,Zhenzhu Fu,Dan He,Song Lin He 한국화훼학회 2016 화훼연구 Vol.24 No.2

In the present study, the plantlets in vitro of Paeonia suffruticosa ‘Wu Long Peng Sheng’ were used as laboratory materials. The proteome during adventitious root induction process was investigated to sift the related proteins by two-dimensional electrophoresis and mass spectrometry. The results indicated that the protein spots were concentrated in the acidity gel region (pH 4 - 7) and the spots number had a dynamic change ranged from 373 to 462 at the process of root induction (0 – 7 d). 8 spots significantly changed were analyzed with a mass spectrometer and identified using associated software and databases. The peptide information of the 8 spots was similar to the ATP synthase β-subunit of P. suffruticosa (Spots 1 - 4 and 8), P. tenuifolia (Spots 5), P. californica (Spot 6) and P. brownie ( Spots 7) r espectiv ely. T he expression levels of protein spots 1, 4, 5, 6 and 7 was dramatically downregulated, and that of protein spots 2 and 3 had a slightly opposite tendency on the 3rd day. The obviously decreased period is particularly interesting as it was consistent with the induction period of adventitious root primordial of tree peony plantlet in vitro. The ATP synthase β-subunit could be consumed for assembling the ATP synthase in order to supply energy to the rooting process. Therefore, we speculated that the ATP synthase β-subunit was involved in adventitious root initiation of tree peony plantlets in vitro and we expect that further studies should be carried out in order to export its action mechanism.

Preparation of Manganese Dioxide Supercapacitors by Secondary Construction of Three-Dimensional Substrates and Ion Embedding

Shi Yihan,Zhang Ming,Zhao Junshan,Zhang Liu,Cui Xumei,Zhu Xinhua,Jin Dandan,Gong Jiali,Yang Dingyu,Li Jitao 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.5

This work used a simple electrochemical reduction method to secondary construct the reduced nickel base (rNi Base) on nickel foam with a nano-core structure. The secondarily constructed base has a large specific surface area, which can increase the mass utilization of the active material. The rNi Base was used as a base for the reduction of nickel on Na+, K+, and NH+4, respectively. MnO2 was electrodeposited under three different cation pre-intercalation treatments, and the mechanism of the effect of different monovalent cations to guide the growth of MnO2 materials was investigated. Finally, rNi/MnO2&Na+ electrode with a special nano cauliflower structure was obtained. The special nanostructure of the electrode enhances its electrochemical performance, possessing 598 F g− 1 ultra-high specific capacitance at a current density of 1 A g− 1 and a high specific capacitance of 307.5 F g− 1 at a high current density of 20 A g− 1, and high specific capacitance maintenance rate of 92.7% after 500 cycles of charging and discharging at a current density of 2 A g− 1. In addition, the symmetrical supercapacitor assembled with this electrode has a very high specific capacitance (401.1 F g− 1 at a current density of 1 A g− 1) and energy density (80.22Wh kg− 1 at a power density of 599.99 W kg− 1).

Experimental Study and Analytical Modeling on Fatigue Properties of Pervious Concrete Made with Natural and Recycled Aggregates

Xudong Chen,Dandan Shi,Nan Shen,Shengtao Li,Saisai Liu 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.1

As a solid pollutant, the recycled aggregate can be reused to replace the natural aggregate to cast pervious concrete, promoting resource recycling and reducing environmental pollution. Pervious concrete is usually applied to transportation engineering as pavements and decks, which are often subjected to fatigue loads in service. Therefore, it is essential to investigate the fatigue mechanical properties of pervious concrete. In this study, four-point cyclic bending loading test of natural aggregate pervious concrete and recycled aggregate pervious concrete were conducted under four different stress levels. By analyzing the experimental results, the mechanical performances, including hysteresis curve characteristics, damping ratio, dynamic elastic modulus and cyclic strain, of two kinds of pervious concrete under cyclic loading were revealed. Based on the improved EPF model, the relationship between fracture parameters, plastic strain and unloading strain were obtained. Besides, the relationship between the loading cycles and the ratio of plastic strain to unloading strain was received according to fatigue testing data under different stress levels. Further, the simplified fatigue model of pervious concrete was proposed and the experimental data was fitted with the model results. The fitting result reached a good agreement.

Experimental Study on Damage Evaluation, Pore Structure and Impact Tensile Behavior of 10-Year-Old Concrete Cores After Exposure to High Temperatures

Xudong Chen,Dandan Shi,Shengshan Guo 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.3

High temperatures impose a negative effect on the mechanical properties of concrete. An experimental setup designed by the theory of nonlinear resonance vibration, the method of mercury intrusion porosimetry (MIP) and split Hopkinson pressure bar (SHPB) were used to test damage, porosity and mechanical properties of the pre-heated Brazilian discs of 10-year-old concrete respectively. According to the nondestructive test, the hysteretic nonlinearity parameters βh became larger as the temperature went up. The damage calculated by βh, which was 0, 0.57, 0.88 and 0.95 at 20 °C, 200 °C, 400 °C and 600 °C respectively, could be fitted by a power function. Based on MIP, the compound lognormal distribution model was used to simulate the pore size distributions. The quantitative relationship between porosity and damage was established by a power function, with the porosities of 13.96% at 20 °C, 15.77% at 200 °C, 19.17% at 400 °C and 20.22% at 600 °C. Finally, by the method of impact splitting tensile tests under gas pressures of 0.3 MPa, 0.4 MPa and 0.5 MPa, which represented impact velocity of 7.11 m/s, 10.26 m/s and 13.02 m/s respectively, the dynamic tensile strengths were obtained and the quantitative relationship between damage and macroscopic splitting tensile strength was established and the average value of exponential parameter b was 0.281.

Cryptotanshinone ameliorates placental oxidative stress and inflammation in mice with gestational diabetes mellitus

Na Wang,Xiujuan Dong,Dandan Shi,Na Li,Qun Zhang 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.7

Gestational diabetes mellitus (GDM) is a conditionaldiabetes which is defined as any degree of glucoseintolerance or high blood glucose levels during any phase ofpregnancy. It causes chronic severe damage to health of thepregnant women and their offspring. In this study, we aimedto study the protective effects of Cryptotanshinone on GDMrelatedimpairments. We measured blood glucose levels,serum insulin levels, biochemical indexes, oxidative stress,inflammation and the activation of NF-κB signaling pathwayin the blood and placenta of GDM mice. It is found thatCryptotanshinone significantly decreased blood glucose levels,oxidative stress, inflammation and NF-κB signaling withan increase of serum insulin levels in the placenta and bloodof GDM mice. Taken together, Cryptotanshinone effectivelyameliorated GDM, which suggested that Cryptotanshinone could be served as a promising therapeutic drug for GDMpatients.

Bone Morphogenetic Protein 9 Overexpression Reduces Osteosarcoma Cell Migration and Invasion

Zilan Lv,Ya-guang Weng,Dandan Yang,Jie Li,Min Hu,Min Luo,Xiaoqin Zhan,Peipei Song,Chen Liu,Huili Bai,Baolin Li,Yang Yang,Yingying Chen,Qiong Shi 한국분자세포생물학회 2013 Molecules and cells Vol.36 No.2

Transforming growth factor- (TGF-) is known to pro-mote tumor migration and invasion. Bone morphogenetic proteins (BMPs) are members of the TGF- family expressed in a variety of human carcinoma cell lines. The role of bone morphogenetic protein 9 (BMP9), the most powerful osteogenic factor, in osteosarcoma (OS) progression has not been fully clarified. The expression of BMP9 and its receptors in OS cell lines was analyzed by RT-PCR. We found that BMP9 and its receptors were expressed in OS cell lines. We further investigated the influence of BMP9 on the biological behaviors of OS cells. BMP9 overexpression in the OS cell lines 143B and MG63 inhibited in vitro cell migration and invasion. We further investigated the ex-pression of a panel of cancer-related genes and found that BMP9 overexpression increased the phosphorylation of Smad1/5/8 proteins, increased the expression of ID1, and reduced the expression and activity of matrix metalloproteinase 9 (MMP9) in OS cells. BMP9 silencing induced the opposite effects. We also found that BMP9 may not affect the chemokine (C-X-C motif) ligand 12 (CXCL12)/C-X-C chemokine receptor type 4 (CXCR4) axis to regulate the invasiveness and metastatic capacity of OS cells. Interestingly, CXCR4 was expressed in both 143B and MG63 cells, while CXCL12 was only detected in MG63 cells. Taken together, we hypothesize that BMP9 inhibits the migration and invasiveness of OS cells through a Smad-dependent pathway by downregulating the expression and activity of MMP9.