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Wang H.,Ministry of Forestry Bioethanol Research Center | Wang H.,Hunan Engineering Research Center for Woody Biomass Conversion | Wang H.,Central South University of forestry and Technology | Huang S.,Changsha Environmental Protection College | And 16 more authors.
Journal of Biobased Materials and Bioenergy | Year: 2017

A robust system of biocatalyst is key to the efficient conversion of lignocellulose to bioethanol. In this paper, three metabolic enhancement strategies (transfer of desirable foreign genes, carbon flux redirection, and co-culture of metabolically complementing strains) were applied for improved conversion of lignocellulosic ethanol. The transformation of heterologous xylose reductase gene into Saccharomyces cerevisiae resulted in no significant improvement. The knockout of the pyruvate formate lyase gene in Escherichia coli redirected the carbon flux and enhanced ethanol production. The co-culture of S. cerevisiae and E. coli KO11 significantly improved ethanol conversion relative to single culture. In conclusion, co-culture may be the most efficient and cost-effective way for improving conversion of lignocellulosic ethanol. Copyright © 2017 American Scientific Publishers. All rights reserved.


Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc. | Zhan P.,Central South University of forestry and Technology | Koopman B.,University of Florida | And 2 more authors.
International Journal of Green Energy | Year: 2015

Simultaneous saccharification and cofermentation (SSCF) experiments were conducted to optimize the conversion of paper sludge to ethanol using co-culture of Saccharomyces cerevisiae and Escherichia coli KO11. The fermentation parameters were optimized at 5 wt.% substrate via orthogonal experiments: 25 FPU/g cellulase, 38°C, 6 wt.% inoculums, and 1:1 S. cerevisiae/E. coli KO11. The ethanol conversion efficiency of co-culture was higher than that of single culture of S. cerevisiae or E. coli KO11 in 72 h fermentation. The maximum ethanol yield achieved by co-culture was 5.69 g/L, which corresponds to a theoretical conversion rate of 63.06 wt.%. The consumption of total reducing sugars reached 90.8%, with higher glucose utilization relative to xylose. © 2015 Taylor & Francis Group, LLC.


Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc | Zhan P.,Central South University of forestry and Technology | Koopman B.,University of Florida | And 2 more authors.
Clean Technologies and Environmental Policy | Year: 2012

The Gordonia strain JW8 was successfully isolated, characterized, and tested for bioaugmentation of pulp and paper wastewater. With significant degradation of alkaline lignin, JW8 has the potential to render pulp and paper wastewater more biodegradable, which is of much interest to wastewater treatment. The sequencing batch reactor (SBR) inoculated with JW8 significantly enhanced the organic pollutants removal of pulp and paper wastewater compared to the control, achieving the best removal rates of 96.4% and 87.8% for biochemical oxygen demand (BOD) and chemical oxygen demand (COD), respectively. A considerable decrease of BOD/COD ratio in wastewater was also achieved in the bioaugmented SBR. However, a drawback caused by JW8 inoculation was the resultant high sludge volume index and biological foaming and bulking, which can be controlled by food/mass adjustment. The denaturing gradient gel electrophoresis analysis suggested that bioaugmentation with JW8 had a slight effect on the microbial dynamics, but more research is needed to understand the relationship between the microbial dynamics and pollutant removal. © US Government 2012.


Wang Q.,Central South University of forestry and Technology | Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc | Zhan P.,Central South University of forestry and Technology | And 2 more authors.
Advanced Materials Research | Year: 2013

Cell suspension cultures of Jatropha curcas were established and optimized in shake flasks. The stem segments of Jatropha curcas were taken as the explants for studying the techniques of callus induction and cell suspension cultures. The result shows that the optimal medium for callus induction is MS+2,4-D0.6mg/L+ BA1.0mg/L + Sucrose 30g/L, in which the callus is humid, loose and colorful. The fine suspension cell system have been established by inoculating the callus in the medium of MS+NAA0.2mg/L+2,4-D1.0mg/L+BA0.5mg/L for 13 days of cultivation, and the rotation speed should be lower than 120rpm in the culture of oscillation. QD-labeled chitosan-DNA complexes as nano transgenic system, using CdSe as bio-labels and chitosan-DNA(CS-DNA) as nano-scale genic carriers, were prepared and shown to have uniform particle sizes and superior fluorescence properties. Confocal laser scanning microscopy(CLSM) confirmed the target DNA from QD-labeled chitosan-DNA complexes was integrated into the plant cell and suggest the possibility of stable transformation in Jatropha curcas. © (2013) Trans Tech Publications, Switzerland.


Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc. | Wang Q.,Central South University of forestry and Technology | Zhang L.,Central South University of forestry and Technology | Kong Q.,Central South University of forestry and Technology
Journal of Bionanoscience | Year: 2013

A low cost aqueous-based procedure was developed to prepare high quality CdSe QDs/chitosan- DNA complexes. Self-assembling of quantum dots (QDs) were used to label chitosan-DNA nanoparticles via electrostatic interaction. The optimal synthesis scheme was established by Fluorescence spectroscopy and Zetasizer Nano ZS. The nano transgenic system of QDs labeling chitosan-DNA complex was shown to have good fluorescence properties and uniform particle size. Cell suspension cultures of Jatropha curcas were established and optimized in shake flasks. The complex can be used as nano-scale gene carriers into cells of Jatropha curcas. Inverted fluorescent microscope (IFM) confirmed that less than 0.5 mg/L of BA and 2-3 minutes of ultrasound time would enhance the transformation efficiency. Copyright © 2013 American Scientific Publishers. All rights reserved.


Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc. | Liu B.,Central South University of forestry and Technology | Liu B.,Chinese Academy of Forestry | And 4 more authors.
Journal of Biobased Materials and Bioenergy | Year: 2015

An Agrobacteriuim-mediated Jatropha curcas transformation procedure has been optimized around high frequency leaf disc regeneration using phosphomannose isomerase (pmi) gene as biosafe selectable marker. A mannose to sucrose ratio of (20 g/10 g)·L-1 was found to be optimal as selection pressure. Cephalothin as a bacteriostat was optimized at 500 mg·L-1 for inhibition of Agrobacteriuim overgrowth without destructive effect on callus induction. The effect of acetosyringone concentration, inoculation duration, and co-cultivation time was evaluated and found to be most desirable at 0.02 mM, 10 min and 2 days, respectively. Sonication treatment had a suppressing effect on resistant shoots induction. The transformation efficiency with mannose selection was twice of that with kanamycin selection. PCR amplification identified 6 positive plants from 12 independent mannose-resistant plants. This efficient and biosafe transformation system is of significance to facilitating the genetic improvement of J. curcas as a promising biodiesel plant and also to alleviating public concerns on the wide use of transgenic energy plants. Copyright © 2015 American Scientific Publishers All rights reserved.


Zhan P.,Central South University of forestry and Technology | Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc. | He G.,Central South University of forestry and Technology | And 2 more authors.
ISWREP 2011 - Proceedings of 2011 International Symposium on Water Resource and Environmental Protection | Year: 2011

Pulp and paper process residuals are primarily made up of lignin, cellulose and semicellulose. In this study we attempted to apply environmentally friendly and economically feasible technologies to separate and utilize those components for beneficial purposes. Biological acid precipitation was shown to be suitable for the separation of lignin from the process wastewater. In the case of cellulose and semicellulose, bioconversion was explored to produce fuel ethanol using simultaneous saccharification and cofermentation (SSCF). The organic acids (mainly citric acid and acetic acid) produced from Saccharomycopsis Lipolytic can be achieved at the lowest pH (3.6) and in this situation the maximum lignin precipitation (78.6%) occurred. Biological acid precipitation also leads to good removal of COD and color, reaching 87.6% and 68.4%, respectively. Bioconversion of pulp and paper sludge by SSCF resulted in maximum ethanol concentration of 5.69g/L using mixed cultures of Saccharomyces cerevisiae and Escherichia coli KO11. © 2011 IEEE.


Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc. | Zhang L.,Central South University of forestry and Technology | Qin L.,Central South University of forestry and Technology | And 3 more authors.
Advanced Materials Research | Year: 2012

Trichoderma reesei Rut C30 was treated by UV irradiation to obtain hypercellulolytic strains. After two rounds of selection and 7 rounds of subculturing, four mutant strains, specifically A5, A9, A13, and A22, were obtained. Compared with the parent strain, the filter paper activities (FPAs) of A5, A9, A13, and A22 increased by 31.01%, 29.83%, 55.35%, and 32.27%, respectively. Random amplified polymorphic DNA analysis demonstrated genetic diversity between the mutants. The maximum FPA of A13 was determined by a central composite design to be 6.09 U/mL. During poplar hydrolysis, the mixed cellulase of A13 and Eupenicillium javanicum ZN-205 resulted in superior production of reducing sugar compared with either of the single cellulase counterparts. The maximum amount of reducing sugar produced by 5% substrate was 25.75g/L in, and the corresponding saccharification rate was 78.18%. © (2012) Trans Tech Publications, Switzerland.


Wang Q.,Central South University of forestry and Technology | Chen J.,Central South University of forestry and Technology | Chen J.,Transpoints Inc. | Zhang H.,Central South University of forestry and Technology | And 4 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2011

Fluorescent quantum dots (QDs) have shown great promise for use as biolabels in cell and animal biology and more recently in plant sciences. An important use of QDs is for monitoring the dynamics, intracellular trafficking, and fate of carrier-DNA nanocomplexes in cell transfection and potentially in plant transformation. In this study, a low cost aqueous procedure has been developed to efficiently prepare biocompatible QDs for monitoring nanoparticle-mediated gene transfer in conjunction with molecular breeding of Jatropha curcas. Water-soluble CdSe nanoparticles were synthesized by self-assembly using L-Cysteine as stabilizer and optimal synthesis scheme established by fluorescence spectroscopy. The QDs were used to label chitosan-DNA nanoparticles via electrostatic interaction and the resultant QD-labeled chitosan-DNA complexes were shown to have superior fluorescence properties with red shift of emission and absorption spectra relative to the CdSe QDs alone. This system is being explored as a superior alternative to Agrobacterium-mediated genetic transformation of Jatropha curcas cells. PCR amplification of the full length of the carried reporter gene (GFP) suggests that the DNA was not digested in Jatropha curcas cells transfected with CdSe/CS-DNA complexes. Furthermore, GFP gene expression in the transfected callus cells, as evidenced by fluorescence detection, suggests that the target DNA was integrated into the plant genome. © 2011 American Scientific Publishers.

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