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Fan X.,Tianjin University of Science and Technology | Sun Y.,Tianjin University of Science and Technology | Liu X.,Tianjin University of Science and Technology | Qiao C.,Tianjin University of Science and Technology | Qiao C.,Tianjin PeiyangBiotrans Co.
Journal of Computational and Theoretical Nanoscience | Year: 2016

The aim of this study was to prepare polyglutamate-pullulan nanofibers with Characteristic of small diameter and smooth surface by optimized the performance of different electrospinning condition such as electrospinning methods, polyglutamic acid concentration of the solution, polyglutamic acid and pullulan addition ratio, spinning voltage and spinning distance. The optimum conditions obtained with blend spinning method, 40% polyglutamate and 20% pullulan, polyglutamic acid and pullulan addition ratio was 1:12, 14 kV voltage, 15 cm spinning distance at 0.3 mL/h feed rate to prepare nanofibers with small diameter and narrow size distribution without beads. The nanofiber fibers had a smaller diameter of 70-110 nm. In addition, the product was analyzed and identified by IR and H1-NMR, and it had better properties and was an ideal material for wound dressing applications. Copyright © 2016 American Scientific Publishers All rights reserved.


Qiao C.,Tianjin University of Science and Technology | Zhang S.,Tianjin University of Science and Technology | Li Z.,Tianjin Polytechnic University | Chen X.,Tianjin University of Science and Technology | And 2 more authors.
Journal of Biobased Materials and Bioenergy | Year: 2013

Poly-(γ-glutamic acid) is a naturally occurring, water-soluble polymer, which has been considered as a promising biodegradable material and there has been a great deal of interest in poly-(γ-glutamic acid) and its derivatives in a wide range of industries. In this paper, the fermentation medium was optimized for increasing the production of poly-(γ-glutamic acid) and reducing impurities in fermentation broth using a new mutant strain, Bacillus. licheniformis CGMCC3336. The results indicated that glucose and yeast extract were beneficial for cell growth and poly-(γ-glutamic acid) production. Especially, when half the yeast extract was replaced by inorganic ammonium nitrate, the production of poly-(γ-glutamic acid) was even increased significantly (17%). In a 30 L bioreactor, more than 35 g/L of poly-(γ-glutamic acid) could be produced in 34 h and the poly-(γ-glutamic acid) productivity was 1.03 g/L/h. The fermentation curve also indicated that the strain was very special comparing with the previous poly-(γ-glutamic acid) producers. Copyright © 2013 American Scientific Publishers All rights reserved.


Qiao C.,Tianjin University of Science and Technology | Song Y.,Tianjin University of Science and Technology | Gao M.,Tianjin University of Science and Technology | Gao X.,Tianjin University of Science and Technology | And 4 more authors.
Journal of Pure and Applied Microbiology | Year: 2014

Effect of two-stage controlled pH and dissolved oxygen concentration (DO) on pullulan production was investigated. Lower pH and higher DO controlled supported the cell growth of Auerobasidiumpullulans CGMCC7055, while higher pH and lower DO controlled stimulated pullulan synthesis. Maximum pullulan production (80.67g/L) was obtained at initially lower pH (3.0) and higher DO (50%), subsequently higher pH (5.0) and lower DO (30%). And was 17.59% (w/w) and 16.07% (w/w) more than those achieved at a two-stage pH (initially pH 3.0 and subsequently 5.0) with uncontrolled DO, and a two-stage DO (initially 50% and subsequently 30%) with uncontrolled pH (initial pH 6.0). Results indicated that combination of the two-stage controlled pH and DO significantly supported mass production of pullulan.This new and improved pullulan production process methodology would conceivably provide significant contribution and insight, and possibly also to other relevant fermentation processes for the improvement of product yield and productivity at the industrial scale.


Qiao C.-S.,Tianjin University of Science and Technology | Peng Q.,Tianjin University of Science and Technology | Liu J.-B.,China Earthquake Administration | Wang Y.-C.,Tianjin University of Science and Technology | And 2 more authors.
Modern Food Science and Technology | Year: 2015

The aim of this study was to develop immobilized systems for wastewater treatment by immobilizing microorganisms in mixed matrices. Two bioactive polysaccharides, sodium alginate (SA) and pullulan (Pu), were used to immobilize microorganisms for wastewater treatment. The optimum mechanical strength, elasticity, and diffusion rate of the immobilized beads were obtained upon addition of 1% Pu polysaccharides and 7% SA. Three base strains of bacteria (which produce amylase, protease, and cellulose) were immobilized in SA or Pu matrices for wastewater treatment. The seeding quantity for microbial immobilization was optimized. A seeding quantity of 200 mL during the preparation of immobilized beads helped achieve efficient wastewater treatment. The total nitrogen (TN) and chemical oxygen demand (COD) removal rates observed during the end of a seven-day treatment period were 65.94% and 77.88%, respectively. Three types of immobilized beads were compounded for wastewater treatment. The immobilized beads 11008, 11009, and 10004 were added at concentrations of 0.75%, 0.50%, and 0.50% of the total volume of wastewater, respectively, and wastewater was treated for seven days continuously; the TN and COD removal rates under these conditions were observed to be up to 90.55% and 91.45%, respectively. ©, 2015, South China University of Technology. All right reserved.


Qiao C.-S.,Tianjin University of Science and Technology | Lin Q.,Tianjin University of Science and Technology | Zhang J.-K.,Tianjin University of Science and Technology | Bai Y.-Z.,Tianjin Peiyang Biotrans Co. | Lu J.-J.,Tianjin Peiyang Biotrans Co.
Modern Food Science and Technology | Year: 2013

The activity of L-lysine decarboxylase was investigated based on Hafnia alvei. Three primary factors that affect the enzyme activity during the assay, i.e. biomass, catalysis time and initial substrate concentration, were chosen and optimized. At last a relatively convenient assay method was determined to assess the activity of L-lysine decarboxylas: adjusting the Optical Density (OD620) of the initial fermentation as 6(diluted 10-fold), and then adding 200 g/L L-lysine to it until its final concentration reached 20 g/L. After incubation at 35°C for 3 hours without shaking, the consumption of the substrate was monitored. One enzyme activity unit is defined as the enzyme amount needed to catalyze 1 μg L-Lysine in 1 min at 35°C. This method was simple and non-polluting. Test results was accurate and reliable (r=0.9901), good stability (RSD=5.07%).


Qiao C.-S.,Tianjin University of Science and Technology | Qiao C.-S.,Tianjin Peiyang Biotrans Co. | Song K.,Tianjin University of Science and Technology | Zhang J.-K.,Tianjin University of Science and Technology | And 2 more authors.
Modern Food Science and Technology | Year: 2013

Two amylase-producing bacteria strains named Bacillus thuringiensis TKFW r8 and Bacillus subtilis TKFW 10004, and two protease-producing bacteria strains named Bacillus cereus. Frankland TWKF 11014 and Bacillus nattoTWKF 11002, were screened from 27 strains of the laboratory tested strains according to the principle of the enzyme good production and no antagonism. The 4 strains, Saccharomyces cerevisiae (Saccharomyces cerevisiae Hansen, TKFW 13024) and Lactobacillus (Lactobacillus plantarum, TWKF 12006) were combined to deal with Kitchen waste in spring. Results showed kitchen waste smelled wine fragrance without foul odour, It indicated that the kitchen waste in situ treatment had certain reduction effect and avoided the secondary pollution. To ensure biosafety of the strains, the unknown strain named TKFW r8 was identified to be Bacillus thuringiensis with 16S rDNA sequence analysis.


Qiao C.-S.,Tianjin University of Science and Technology | Qiao C.-S.,Tianjin Peiyang Biotrans Co. | Zheng Z.-D.,Tianjin University of Science and Technology | Meng D.,Tianjin University of Science and Technology | And 2 more authors.
Modern Food Science and Technology | Year: 2014

In this paper, metabolic flux and enzyme activity analysis for wild type Aureobasidium pullulans TKPM00006 and its mutant strain CGMCC3337 was conducted in 5 L bioreactor in the same conditions. The mechanism of biosynthesis of PMLA using Aureobasidium pullulans was investigated. The results showed that the biomasses in the two strains during the fermentation process were almost the same, but the accumulated yield was 20.54 g/L and 30.2 g/L, respectively. Through the metabolic flux analysis and key enzyme activity determination, it was found that pyruvate carboxylation pathway and glyoxylate pathway were the main pathways in PMLA synthesis, while TCA pathway was weak in the two strains at the post fermentation. This was confirmed by adding metabolic inhibitors and intermediate metabolites into medium. Enzyme activity analysis also confirmed that pyruvate carboxylation pathway was strengthened in the high yield strain whose PMLA synthesis ability stronger than the wild strain. The carbon flux distribution on pyruvate node could be manipulated by genetic manipulation and fermentation control. The enhanced flux in pyruvate carboxylation pathway decreased other pathways flux, thereby reducing the byproduct generation and improving PMLA yield.

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