National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology

Tianjin, China

National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology

Tianjin, China
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Zhang C.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Du S.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Guo L.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Xu Q.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | And 2 more authors.
Journal of Chemical and Pharmaceutical Research | Year: 2014

Adenylosuccinate synthetase (AdSS), encoded by purA, is generally considered as one of the rate-limiting enzymes involved in the de novo biosynthesis of adenosine. In this study, effect of purA overexpression on adenosine production was investigated and Bacillus subtilis XGL-XY and XGL-A were constructed. B. subtilis XGL-XY harboring a recombinant plasmid pBEA containing purA showed 25.5% and 29.2% increased adenosine production and yield but a decline in cell growth. Considering the metabolic burden caused by pBEA, an additional purA gene under the control of P43 promoter was integrated into the B. subtilis XGL genome in purA locus by single crossover, resulting in B. subtilis XGL-A. The strain exhibited improved adenosine production, yield and similar cell growth with B. subtilis XGL. Furthermore, lowered IMP concentration was detected in B. subtilis XGL-XY and B. subtilis XGL-A. Fed-batch fermentation assay showed that, compared with B. subtilis XGL, 29.4% and 18.3% increase in adenosine production and yield and up to 17.3 g/L and 0.207 g/g glucose was achieved by B. subtilis XGL-A. Above all, it can be concluded that AdSS is a crucial enzyme in adenosine synthesis and purA overexpression could drove more metabolic flux from IMP to adenosine synthesis and thus enhance adenosine production. © 2014, Journal of Chemical and Pharmaceutical Research. All rights reserved.


Zhang C.,Tianjin University of Science and Technology | Zhang C.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Feng J.,Tianjin University of Science and Technology | Feng J.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | And 5 more authors.
Journal of Chemical and Pharmaceutical Research | Year: 2014

To investigate function and enzymatic characteristics of L-amino acid deaminase of Proteus mirabilis from acute pyelonephritis patients, L-amino acid deaminase encoding genes (pmzd1 and pmzd2) were cloned from P. Mirabilis ZD1 and P. mirabilis ZD2 and nucleotide as well as amino acid sequences were analyzed. Prokaryotic expression system was established to express recombinant PMZD1 and PMZD2 and enzymatic characteristics were analyzed. Growth promotion tests were performed to establish the iron chelation and growth promotion effect of recombinant enzymes products. Results showed that recombinant PMZD1 and PMZD2 exhibited function of second type of L-amino acid deaminase but different in enzymatic characteristics, including affinity to substrates, reaction speed as well as optimal reaction temperature and pH, probably due to different amino acid sequences. Growth promotion tests indicated that products of the recombinant enzymes had growth promotion activities to P. mirabilis but exhibited no difference between the two enzymes. © 2014, Journal of Chemical and Pharmaceutical Research. All rights reserved.


Liu F.-F.,Tianjin University | Liu F.-F.,Key Laboratory of Industrial Fermentation Microbiology Ministry of Education | Liu F.-F.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Liu F.-F.,Tianjin University of Science and Technology | And 3 more authors.
Wuli Huaxue Xuebao/ Acta Physico - Chimica Sinica | Year: 2017

Alzheimer’s disease (AD) is mainly caused by the aggregation of amyloid-β (Aβ) protein. Development of inhibitors to prevent Aβ aggregation is the most efficient method to devise a cure for AD. Aβ aggregation has been found to be inhibited by the affibody protein ZAβ3, selected viaphage display. However, the molecular basis of affinity interactions between Aβ and ZAβ3, the interaction region, and important residues of Aβ and ZAβ3remain unclear. Herein, molecular dynamics simulations and free energy calculation and decomposition using the molecular mechanics-Poisson-Boltzmann surface area method (MM-PBSA) were coupled toinvestigate the molecular mechanism underlying interactions between Aβ and ZAβ3. Interactions between the β-strand of ZAβ3 and Aβ16–40were found to contribute greatly to their binding free energy, while that between the α-helix of ZAβ3 and ZAβ3 has a smaller contribution. Based on the free energy decomposition, hotspot residues of ZAβ3 are E15, I16, V17, Y18, L19, P20, N21, and L22 and those of Aβ16–40include F19, F20, A21, E22, D23, K28, I31, I32, G33, L34, M35, V36, G38, and V40. ZAβ3stabilizes the β-sheet by burying the two mostly nonpolar faces of the Aβ hairpin within a large hydrophobic tunnel-like cavity formed by the α-helix. The identified binding motif can be used as a starting point for rational design of protein inhibitors with high affinityfor Aβ to prevent Aβ aggregation. The three key characteristics of efficient protein inhibitors are the presence of a high-affinity site (β-strand), a large accessory structure (α-helix), and a stable conformation owing to disulfide bonds. The high-affinity site can competitively bind to the Aβ monomer, and the large accessory structure can block other Aβ monomers; both these elements require a stable conformation via disulfide bonds. These three characteristics of a protein inhibitor can be employed together to suppress Aβ aggregation. © Editorial office of Acta Physico-Chimica Sinica.


Gui Y.,Tianjin University of Science and Technology | Gui Y.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Liang J.,Tianjin University of Science and Technology | Liang J.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | And 9 more authors.
Lecture Notes in Electrical Engineering | Year: 2015

In this study, the calibration models for monitoring concentrations of glutamate and glucose in the temperature-triggered glutamate fermentation process were developed by near infrared (NIR) spectroscopy. The NIR measurements of samples were analyzed by partial least-squares (PLS) regression with selecting spectral pre-processing methods and different wavelengths. The root-mean square errors of cross-validation (RMSECV) of glutamate and glucose were 2.73 and 1.92 g/L, respectively. The determination coefficients (R2) were 0.996 and 0.982, respectively. The residual predictive deviation (RPD) was 17.8 and 8.37, respectively. These results showed that all models had good predictive ability. New batch fermentation as an external validation was used to check the models. Compared with concentrations of predict value and measured value, the determination coefficient was 0.992 and 0.951, respectively. The average relative errors were 5.79 and 7.38%, respectively. These results showed that prediction model could predict and monitor the temperature-triggered glutamate fermentation process accurately and quickly, and thus theoretical basis for the real-time control and optimization in the temperature-triggered glutamate fermentation process was provided. © Springer-Verlag Berlin Heidelberg 2015.


Li Z.-H.,Tianjin University of Science and Technology | Li Z.-H.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Li Z.-H.,Tianjin Engineering Laboratory of Efficient and Green Amino Acid Manufacture | Zhang C.-L.,Tianjin University of Science and Technology | And 5 more authors.
Lecture Notes in Electrical Engineering | Year: 2015

To investigate the production of L-glutamic acid with high yield as well as improved purity, the optimization of crystallization process was conducted. During this study, various physicochemical parameters (e.g., initial temperature, cooling rate, acid adding rate, ultrasonic time, and stirring speed) of concentrated isoelectric crystallization method were evaluated to optimize the yield and purity of L-glutamic acid. The optimum crystallization parameters are as follows: acid adding rate 0.5 mL/min, ultrasonic time 10 min, and stirring speed 200 rpm. The yield of L-glutamic acid at optimal condition was 95.4%, attaining a 6.5% growth. The purity of crystallized product exceeded 99%, giving a rise of 4%. The optimal crystallization process with higher yield and improved purity reduces the energy consumption and thus promotes sustainable development. © Springer-Verlag Berlin Heidelberg 2015.


Xu Q.-Y.,Tianjin University of Science and Technology | Xu Q.-Y.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Cheng L.-K.,Tianjin University of Science and Technology | Cheng L.-K.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | And 8 more authors.
Lecture Notes in Electrical Engineering | Year: 2015

L-tryptophan is an essential amino acid, and the work for L-tryptophan production by microbial fermentation has important practical significance with the development of L-tryptophan market. In this study, according to the principle of metabolic engineering, the medium of L-tryptophan fermentation by the strain Escherichia coli TRTH was optimized. The accumulation of by-products was decreased and production of desired product was increased by adding sodium citrate to medium. The effect of sodium citrate on L-tryptophan fermentation was investigated in a 30 L fermentor. The results indicated that when L-tryptophan fermentation with the medium containing 2 g/L sodium citrate, as compared with the medium no containing sodium citrate, the biomass, L-tryptophan production and glucose conversion rate were increased by 2.57, 5.32, 4.21%, and the accumulation of acetate, pyruvate and lactate were decreased by 5.15, 4.89, 5.23%. With the medium containing 2 g/L sodium citrate for L-tryptophan fermentation, the biomass, L-tryptophan production and glucose conversion rate were 42.7, 35.7 and 18.2% respectively. © Springer-Verlag Berlin Heidelberg 2015.


Li Y.,Tianjin University of Science and Technology | Li Y.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Sun L.,Tianjin University of Science and Technology | Feng J.,Tianjin University of Science and Technology | And 9 more authors.
Bioprocess and Biosystems Engineering | Year: 2016

Production of l-glutamate using a biotin-deficient strain of Corynebacterium glutamicum has a long history. The process is achieved by controlling biotin at suboptimal dose in the initial fermentation medium, meanwhile feeding NH4OH to adjust pH so that α-ketoglutarate (α-KG) can be converted to l-glutamate. In this study, we deleted glutamate dehydrogenase (gdh1 and gdh2) of C. glutamicum GKG-047, an l-glutamate overproducing strain, to produce α-KG that is the direct precursor of l-glutamate. Based on the method of l-glutamate fermentation, we developed a novel double-phase pH and biotin control strategy for α-KG production. Specifically, NH4OH was added to adjust the pH at the bacterial growth stage and NaOH was used when the cells began to produce acid; besides adding an appropriate amount of biotin in the initial medium, certain amount of additional biotin was supplemented at the middle stage of fermentation to maintain a high cell viability and promote the carbon fixation to the flux of α-KG production. Under this control strategy, 45.6 g/L α-KG accumulated after 30-h fermentation in a 7.5-L fermentor and the productivity and yield achieved were 1.52 g/L/h and 0.42 g/g, respectively. © 2016, Springer-Verlag Berlin Heidelberg.


Jiang Y.-Z.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Zhang C.-L.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Wang Z.-G.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Xie X.-X.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | And 2 more authors.
Modern Food Science and Technology | Year: 2014

Glutamine has important effects in biological systems and has been widely used in many areas, including in the food and medicine industries. Glutamic acid is the precursor for glutamine biosynthesis, and is the most common by-product in glutamine fermentation. Previous studies have shown that the protein encoded by NCgl1221 is an important glutamic acid exporter and that pyruvate carboxylase is a key enzyme in the feedback pathway of Corynebacterium glutamicum. In order to reduce glutamic acid accumulation during glutamine fermentation and to improve the yield of glutamine, in this study, NCgl1221 of the glutamine-producing strain GM34 was knocked out using homologous recombination technology, resulting in the construction of the mutant strain GM34ΔNCgl1221. Pyc encoding pyruvate carboxylase was also overexpressed in the constructed strain GM34-pXMJ19pyc. Fermentation carried out in 5-L bottles showed that NCgl1221 knockout reduced glutamic acid accumulation by 19.05%. Overexpression of pyc resulted in a promotion of glutamine production and conversion rate by 5.54% and 2.37%, respectively. Taken together, these results demonstrate that NCgl1221 knockout and pyc overexpression can effectively reduce glutamic acid accumulation and improve glutamine production. ©, 2014, South China University of Technology. All right reserved.


Gui Y.,Tianjin University of Science and Technology | Gui Y.,National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology | Gui Y.,Tianjin Engineering Laboratory of Efficient and Green Amino Acid Manufacture | Ma Y.,Tianjin University of Science and Technology | And 14 more authors.
Journal of Biotechnology | Year: 2016

Here, we report the complete genome sequence of Corynebacterium glutamicum CP, an industrial l-leucine producing strain in China. The whole genome consists of a circular chromosome and a plasmid. The comparative genomics analysis shows that there are many mutations in the key enzyme coding genes relevant to l-leucine biosynthesis compared to C. glutamicum ATCC 13032. © 2016 Elsevier B.V.


Wang L.,South China University of Technology | Cao Z.,Tianjin University of Science and Technology | Cao Z.,Key Laboratory of Industrial Fermentation Microbiology | Hou L.,Tianjin University of Science and Technology | And 10 more authors.
Applied Microbiology and Biotechnology | Year: 2016

Citric acid is produced by an industrial-scale process of fermentation using Aspergillus niger as a microbial cell factory. However, citric acid production was hindered by the non-fermentable isomaltose and insufficient saccharification ability in A. niger when liquefied corn starch was used as a raw material. In this study, A. niger TNA 101ΔagdA was constructed by deletion of the α-glucosidase-encoding agdA gene in A. niger CGMCC 10142 genome using Agrobacterium tumefaciens-mediated transformation. The transformants A. niger OG 1, OG 17, and OG 31 then underwent overexpression of glucoamylase in A. niger TNA 101ΔagdA. The results showed that the α-glucosidase activity of TNA 101ΔagdA was decreased by 62.5 % compared with CGMCC 10142, and isomaltose was almost undetectable in the fermentation broth. The glucoamylase activity of the transformants OG 1 and OG 17 increased by 34.5 and 16.89 % compared with that of TNA 101ΔagdA, respectively. In addition, for the recombinants TNA 101ΔagdA, OG 1 and OG 17, there were no apparent defects in the growth development. Consequently, in comparison with CGMCC 10142, TNA 101ΔagdA and OG 1 decreased the residual reducing sugar by 52.95 and 88.24 %, respectively, and correspondingly increased citric acid production at the end of fermentation by 8.68 and 16.87 %. Citric acid production was further improved by decreasing the non-fermentable residual sugar and increasing utilization rate of corn starch material in A. niger. Besides, the successive saccharification and citric acid fermentation processes were successfully integrated into one step. © 2016, Springer-Verlag Berlin Heidelberg.

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