Zhijie Sun

State University of New York, New York City, New York, United States

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Publications (4)13.29 Total impact

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    ABSTRACT: In this study the influence of the insoluble solids in nano-filtrated sugar maple hemicellulosic hydrolysate on the metabolic behavior of Pichia stiptis was investigated. The particle properties of hemicellulosic hydrolysate were analyzed. Phosphoric acid and ammonium (PA) were applied to remove the particles. The metabolic behavior and growth property of P. stipitis in particle--removed hydrolysate was measured. Results demonstrated that the average particle size and zeta potential of the untreated hydrolysate were 2266.9±78.2 nm and -6.09±0.49 mV. Xylose consumption and ethanol production rate were significantly decreased when particle content is greater than 1.63 g/L. Because the majority of particles (34 g/L) were removed from hydrolysates by phosphoric acid and ammonium treatment, the fermentability of the hydrolysate was significantly improved. These results indicated particles play an important role in hydrolysate inhibition effect.
    Bioresource Technology 01/2011; 102(2):2133-6. · 5.04 Impact Factor
  • Zhijie Sun, Shijie Liu
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    ABSTRACT: Using fermentation to replace chemical processes in the production of acetone and butanol depends largely on the availability of inexpensive and abundant raw materials and efficient conversion of these materials to solvents. In this study solvent production of Clostridium acetobutylicum ATCC824 from nano-membrane concentrated hemicellulosic hydrolysate was investigated. Alkali pretreatment methods were applied to improve fermentability of nano-membrane concentrated hemicellulosic hydrolysate and solvent production by ATCC824. Results demonstrated that though nanofiltration could remove nearly all small molecular organic acids (acetic acid, formic acid), furfural and HMF, the resulting hydrolysate found to be still inhibiting solvent production of C. acetobutylicum. Solid particles separated from filtering hydrolysate were found not toxic to cells when xylose or glucose was used as carbon resource. Overliming treatment can significantly improve the ultimate butanol concentration to 7 g l−1 from 0.8 g l−1. Providing cells with more carbon source at the final stage of fermentation was found to have no impact on butanol production, but acetic acid and butyric acid production were found to increase significantly. The reasons leading to low solvent yield at later fermentation stages is not cell degeneration, but the toxicity of butanol and inhibitors remaining in the hydrolysate.
    Biomass & Bioenergy - BIOMASS BIOENERG. 01/2010;
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    ABSTRACT: Hemicellulose is a potential by-product currently under-utilized in the papermaking industry. It is a hetero-carbohydrate polymer. For hardwood hemicelluloses, D-xylose is the major component upon depolymerization. At SUNY-ESF, wood extracts were obtained by extracting sugar maple wood chips with hot water at an elevated temperature. The wood extracts were then concentrated and acid hydrolyzed. Ethanologenic bacteria, E. coli FBR5, had a good performance in pure xylose medium for ethanol production. However, FBR5 was strongly inhibited in dilute sulfuric acid hydrolyzate of hot-water wood extract. FBR5 was challenged by hot-water wood extract hydrolyzate in this study. After repeated strain adaptation, an improved strain: E. coli FBHW was obtained. Fermentation experiments indicated that FBHW was resistant to the toxicity of hydrolyzate in the fermentation media of concentrated hydrolyzate, and xylose was completely utilized by the strain to produce ethanol. FBHW was grown in the concentrated hydrolyzate without any detoxification treatment and has yielded 36.8g/L ethanol.
    Biotechnology advances 01/2010; 28(5):602-8. · 8.25 Impact Factor
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    ABSTRACT: In this study, the production of n-butanol via fermentation of sugar maple hemicellulose hydrolysate, using Clostridium Acetobutylicum ATCC824 and Clostridium Beijerinckii ATCC 35702 were investigated. When using static pH-uncontrolled fermentation in untreated hydrolysate, ATCC 824 only produced 0.2g/L butanol. Over -liming and increasing osmotic pressure of hydrolysate with added phosphate salt significantly increased butanol production from 0.2 to 2.4g/L. However using dynamic pH-controlled stirred tank reactor significantly improved the butanol production of ATCC 824 from the concentrated hydrolysate without treatment. After 96 hours fermentation 53 g/L reducing sugar was consumed and 7 g/L butanol, 2.64g/L acetone and 0.81g/L ethanol were produced by C. acetobutylicum ATCC824. For C. Beijerinckii ATCC 35702 in untreated hydrolysate and at first 48 hours, cells utilized about 35 g/L reducing sugar and produced 4.65 g/L butanol, 2.11g/L ethanol and 2.27g/L acetone. Unfortunately after 48 hours ATCC 35702 stopped growing and utilizing substrate.
    2009 AIChE Annual Meeting; 11/2009

Publication Stats

9 Citations
13.29 Total Impact Points

Institutions

  • 2010
    • State University of New York
      New York City, New York, United States
  • 2009–2010
    • State University of New York College of Environmental Science and Forestry
      • Department of Paper and Bioprocess Engineering
      Syracuse, New York, United States