Key Laboratory of Industrial Fermentation Microbiology

Tianjin, China

Key Laboratory of Industrial Fermentation Microbiology

Tianjin, China
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Zheng H.,Key Laboratory of Industrial Fermentation Microbiology | Zheng H.,Tianjin University of Science and Technology | Zheng H.,Chinese Academy of Agricultural Sciences | Liu Y.,Key Laboratory of Industrial Fermentation Microbiology | And 12 more authors.
Journal of Industrial Microbiology and Biotechnology | Year: 2014

The extreme process condition of high temperature and high alkali limits the applications of most of natural xylanases in pulp and paper industry. Recently, various methods of protein engineering have been used to improve the thermal and alkalic tolerance of xylanases. In this work, directed evolution and site-directed mutagenesis were performed to obtain a mutant xylanase improved both on alkali stability and thermostability from the native Paenibacillus campinasensis Family-11 xylanase (XynG1-1). Mutant XynG1-1B43 (V90R/P172H) with two units increased in the optimum pH (pH 7.0-pH 9.0) and significant improvement on alkali stability was selected from the second round of epPCR library. And the further thermoduric mutant XynG1-1B43cc16 (V90R/P172H/T84C- T182C/D16Y) with 10 C increased in the optimum temperature (60-70 C) was then obtained by introducing a disulfide bridge (T84C-T182C) and a single amino acid substitution (D16Y) to XynG1-1B43 using site-directed mutagenesis. XynG1-1B43cc16 also showed higher thermostability and catalytic efficiency (k cat /K m ) than that of wild-type (XynG1-1) and XynG1-1B43. The attractive improved properties make XynG1-1B43cc16 more suitable for bioleaching of cotton stalk pulp under the extreme process condition of high temperature (70 C) and high alkali (pH 9.0). © 2013 Society for Industrial Microbiology and Biotechnology.


Zheng H.,Key Laboratory of Industrial Fermentation Microbiology | Zheng H.,Tianjin University of Science and Technology | liu Y.,Key Laboratory of Industrial Fermentation Microbiology | liu Y.,Tianjin Key Laboratory of Industrial Microbiology | And 10 more authors.
Bioresource Technology | Year: 2012

A xylanase gene (xynG1-1) from Paenibacillus campinasensis G1-1 was expressed in Bacillus megaterium MS941 and a high level of extracellular xylansae activity (304.26. IU/mL) was achieved after induction with 0.5% xylose. The purified recombinant xylanase (XynG1-1R) revealed optimal activity at 60. °C and pH 7.0 and retained 79% and 81% activity after incubation without substrate at 60. °C, pH 5.0 and pH 8.0 for 3. h, respectively. Application of XynG1-1R (15. IU/g pulp) to cotton stalk pulp bleaching increased brightness by 3.65% over that of the control without the xylanase and reduced the need for chlorine compounds by 50% without loss of brightness and pulp fiber qualities. When XynG1-1R (80. IU/g paper sludge) was used in combination with mixed cellulolytic enzymes, the saccharification efficiency of recycled paper sludge was increased by 10%. These results indicated that XynG1-1R is a promising candidate for various industrial applications such as biobleaching and bioenergy conversion. © 2012 Elsevier Ltd.


Ren J.J.,Key Laboratory of Industrial Fermentation Microbiology | Shen Y.B.,Key Laboratory of Industrial Fermentation Microbiology | Ge R.L.,Key Laboratory of Industrial Fermentation Microbiology | Wang M.,Key Laboratory of Industrial Fermentation Microbiology
Applied Mechanics and Materials | Year: 2014

Microbial transformation of androst-4-en-3,17-dione (AD; 1) using Colletotrichum lini AS3. 4486 resulted in the production of two metabolites 2 and 3. The structures of these compounds were elucidated by spectroscopic analysis (LC-MS, FTIR and NMR) as 15α-hydroxyandrost-4-en-3,17-dione (15α-OH-AD; 2) and 11α,15α-dihydroxyandrost- 4-en-3,17-dione (11α,15α-diOH-AD; 3). AD underwent regioselective hydroxylation at 15α position, subsequently hydroxylated at 11α position and converted to compound 3. 11α,15α-diOH-AD as an important metabolic product was pharmaceutical intermediate and the yield was up to 97.58% when the concentration of substrate was 4 g L-1. © (2014) Trans Tech Publications, Switzerland.


Sun X.,Key Laboratory of Industrial Fermentation Microbiology | Sun X.,Tianjin University of Science and Technology | Zhang C.,Key Laboratory of Industrial Fermentation Microbiology | Zhang C.,Tianjin University of Science and Technology | And 8 more authors.
Journal of Industrial Microbiology and Biotechnology | Year: 2012

This study aimed to increase maltose fermentation in industrial baker's yeast to increase its leavening properties. To this end, we overexpressed MAL62 encoding alpha-glucosidase (maltase) and deleted MIG1 encoding a transcriptional repressor that regulates MAL gene expression. Strain overexpressing MAL62 showed 46.3 % higher alpha-glucosidase activity and enhanced leaving activity than the parental strain when tested in glucose-maltose low sugar model liquid dough (LSMLD). Deleting MIG1 was much less effective, but it could further strengthen leavening properties in a strain overexpressing MAL62. The relationship between maltose permease and alpha-glucosidase was further dissected by transforming the two genes. The results indicated that without increasing the maltose permease activity, maltose metabolism could also be enhanced by the increased alpha-glucosidase activity. Previous strategies for strain improvement have targeted the enhancement of alpha-glucosidase and maltose permease activities in concert. Our results suggest that increasing alpha-glucosidase activity is sufficient to improve maltose fermentation in lean dough. © Society for Industrial Microbiology and Biotechnology 2012.


Jia Y.,Key Laboratory of Industrial Fermentation Microbiology | Jia Y.,Tianjin University of Science and Technology | Huo M.,Key Laboratory of Industrial Fermentation Microbiology | Huo M.,Tianjin University of Science and Technology | Jia S.,Tianjin University of Science and Technology
Lecture Notes in Electrical Engineering | Year: 2014

The preparation and characterization of bacterial cellulose (BC)/hyal-uronic acid (HA) nanocomposites are presented in this paper. BC/HA composites have been prepared by solution immersion method, biosynthesis method, and crosslink method. HA concentration (1, 10, and 12.5 g/L) was used as a variable factor. These materials were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared (FTIR) spectroscopy, and X-ray Diffraction (XRD). And tensile strength and young's modulus were tested for composites from solution immersion and biosynthesis. SEM graphs of the composites show that HA penetrated inside the cellulose network, filling the space of the network, and keeping a close interaction with the nanofibrils. FTIR spectra illustrate the integration of HA in the composites derived by solution immersion and crosslink method. The crystallinity index of all three composites was reduced slightly compared with pristine BC, known from XRD spectra. For composites from solution immersion and biosynthesis, the young's modulus and tensile strength of BC/HA have been improved compared with the pure BC. This is due to the enhanced hydrogen bonds offered by the interaction between HA and BC. In summary, all the three methods can provide composites of BC and HA. Further, biocompatibility tests will be carried out to evaluate these materials in terms of the potential applications on the biomedical field. © Springer-Verlag Berlin Heidelberg 2014.


Liu Y.,Tianjin University of Science and Technology | Zhao L.,East China University of Science and Technology | Zhang J.,University of Shanghai for Science and Technology | Zheng Y.,Key Laboratory of Industrial Fermentation Microbiology
Lecture Notes in Electrical Engineering | Year: 2015

Glycerol dehydrogenase (GDH) was a key enzyme for 1,3-propanediol fermentation from glycerol. In this report, gene gdh, encoding GDH of Klebsiella pneumoniae KG1 was gained by PCR with genomic DNA as template. The open reading frame (ORF) of gdh consisted of 1,143 bp and encoded 380 amino acids with a deduced molecular mass of 42 kDa. The gene gdh was overexpressed in E. coli BL21 (DE3) and produced 886-fold higher activity of GDH than that of KG1. The optimum temperature of recombinant GDH was 37 °C and glycerol was the optimum substrate. © Springer-Verlag Berlin Heidelberg 2015.


PubMed | Key Laboratory of Industrial Fermentation Microbiology
Type: Journal Article | Journal: Biotechnology letters | Year: 2015

To acquire a thermostable xylanase, that is suitable for xylooligosaccharide production from pretreated corncobs, the metagenomic method was used to obtain the gene from an uncultured environmental microorganism.A thermostable xylanase-encoding gene (xyn10CD18) was cloned directly from the metagenomic DNA of cow dung compost. When xyn10CD18 was expressed in Bacillus megaterium MS941, extracellular xylansae activity at 106 IU/ml was achieved. The purified recombinant Xyn10CD18 was optimally active at pH 7 and 75 C as measured over 10 min. It retained over 55% of its initial activity at 70 C and pH 7 after 24 h. Its action on birchwood xylan for 18 h liberated xylooligosaccharides with 2-4 of polymerization, with xylobiose and xylotetraose as the main products. When pretreated corncobs were hydrolyzed by Xyn10CD18 for 18 h, the xylooligosaccharides (DP 2-4) products increased to 80% and the xylose was just increased by 3%.Xyn10CD18 is a thermostable endoxylanase and is a promising candidate for biomass conversion and xylooligosaccharide production.


PubMed | Key Laboratory of Industrial Fermentation Microbiology
Type: Journal Article | Journal: Journal of industrial microbiology & biotechnology | Year: 2014

The extreme process condition of high temperature and high alkali limits the applications of most of natural xylanases in pulp and paper industry. Recently, various methods of protein engineering have been used to improve the thermal and alkalic tolerance of xylanases. In this work, directed evolution and site-directed mutagenesis were performed to obtain a mutant xylanase improved both on alkali stability and thermostability from the native Paenibacillus campinasensis Family-11 xylanase (XynG1-1). Mutant XynG1-1B43 (V90R/P172H) with two units increased in the optimum pH (pH 7.0-pH 9.0) and significant improvement on alkali stability was selected from the second round of epPCR library. And the further thermoduric mutant XynG1-1B43cc16 (V90R/P172H/T84C-T182C/D16Y) with 10C increased in the optimum temperature (60-70C) was then obtained by introducing a disulfide bridge (T84C-T182C) and a single amino acid substitution (D16Y) to XynG1-1B43 using site-directed mutagenesis. XynG1-1B43cc16 also showed higher thermostability and catalytic efficiency (k cat /K m ) than that of wild-type (XynG1-1) and XynG1-1B43. The attractive improved properties make XynG1-1B43cc16 more suitable for bioleaching of cotton stalk pulp under the extreme process condition of high temperature (70C) and high alkali (pH 9.0).


PubMed | Key Laboratory of Industrial Fermentation Microbiology
Type: | Journal: Probiotics and antimicrobial proteins | Year: 2017

Bifidobacterium is an important probiotic bacterium and extensively applied to functional food. Its survival is strongly affected by the heat-shock process during manufacture. Acclimation is thought to be able to enhance Bifidobacteriums resistance to heat stress; however, so far little is known about the protein expression changes underlying the adaptation process. In this study, the appropriate acclimation temperature for Bifidobacterium longum was determined as 43C, and 2-dimensional gel electrophoresis-based proteomic analysis was performed to reveal the protein changes in expression levels behind heat acclimation. Twenty proteins displayed significantly expression changes after heat acclimation, including general stress response proteins, metabolic enzymes, components of ABC transporters, transcriptional regulators, and hypothetical proteins. Two important chaperones GroEL and IbpA were found to be induced during heat acclimation, implying that they might play key roles in the heat resistance of acclimation. Although many further studies are needed to explore the complex mechanisms, this study enhances the understanding of protein changes underlying the heat acclimation of Bifidobacterium and provides important molecular clues for its future research.


PubMed | Key Laboratory of Industrial Fermentation Microbiology
Type: Journal Article | Journal: Journal of industrial microbiology & biotechnology | Year: 2016

Ethyl carbamate (EC), a pluripotent carcinogen, is mainly formed by a spontaneous chemical reaction of ethanol with urea in wine. The arginine, one of the major amino acids in grape musts, is metabolized by arginase (encoded by CAR1) to ornithine and urea. To reduce the production of urea and EC, an arginase-deficient recombinant strain YZ22 (carl/carl) was constructed from a diploid wine yeast, WY1, by successive deletion of two CAR1 alleles to block the pathway of urea production. The RT-qPCR results indicated that the YZ22 almost did not express CAR1 gene and the specific arginase activity of strain YZ22 was 12.64 times lower than that of parent strain WY1. The fermentation results showed that the content of urea and EC in wine decreased by 77.89 and 73.78 %, respectively. Furthermore, EC was forming in a much lower speed with the lower urea during wine storage. Moreover, the two CAR1 allele deletion strain YZ22 was substantially equivalent to parental strain in terms of growth and fermentation characteristics. Our research also suggested that EC in wine originates mainly from urea that is produced by the arginine.

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