Yingxin Zhang

Publications (3)9.2 Total impact

• Article: A colorimetric assay method for Co2+ based on thioglycolic acid functionalized hexadecyl trimethyl ammonium bromide modified Au nanoparticles (NPs).

  Fuqiang Zhang, Leyong Zeng, Yingxin Zhang, Haiyan Wang, Aiguo Wu
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  ABSTRACT: A simple, rapid and sensitive colorimetric assay method for detection of Co(2+) through thioglycollic acid (TGA) functionalized hexadecyl trimethyl ammonium bromide (CTAB) modified Au NPs has been discovered in our work. TGA functionalized CTAB modified Au NPs can be aggregated quickly in the presence of Co(2+) through a cooperative metal-ligand interaction. Transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDS), and UV-vis spectra were used to characterize the Au NPs aggregation. The presence of Co(2+) is monitored by a colorimetric response of functionalized Au NPs, and had a detection limit of 3.0 × 10(-7) M. Moreover, the selectivity of this method has been investigated by comparing with other metal ions (Hg(2+), Na(+), Cu(2+), Cd(2+), Ba(2+), Pb(2+), Mn(2+), Ni(2+), Zn(2+), Fe(2+) and Fe(3+)).
  Nanoscale 05/2011; 3(5):2150-4. · 5.91 Impact Factor
• Article: The methane monooxygenase intrinsic activity of kinds of methanotrophs.

  Yingxin Zhang, Jiaying Xin, Linlin Chen, Chungu Xia
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  ABSTRACT: Methanotrophs have promising applications in the epoxidation of some alkenes and some chlorinated hydrocarbons and in the production of a biopolymer, poly-beta-hydroxybutyrate (poly-3-hydroxybutyrate; PHB). In contrast with methane monooxygenase (MMO) activity and ability of PHB synthesis of four kinds of methanotrophic bacteria Methylosinus trichosporium OB3b, M. trichosporium IMV3011, Methylococcus capsulatus HD6T, Methylomonas sp. GYJ3, and the mixture of the four kinds of strains, M. trichosporium OB3b is the highest of the four in the activity of propene epoxidation (10.72 nmol/min mg dry weight of cell [dwc]), the activity of naphthalene oxidation (22.7 mmol/mg dwc), and ability in synthesis of PHB(11% PHB content in per gram dry weight of cell in 84 h). It could be feasible to improve the MMO activity by mixing four kinds of methanotrophs. The MMO activity dramatically decreased when the cellular PHB accumulated in the second stage. The reason for this may be the dilution of the MMO system in the cells with increasing PHB contents. It has been found that the PHB contents at the level of 1-5% are beneficial to the cells for maintenance of MMO epoxidation activity when enough PHB have been accumulated. Moreover, it was also found that high particulate methane monooxygenase activity may contribute to the synthesis of PHB in the cell, which could be used to improve the yield of PHB in methanotrophs.
  Applied biochemistry and biotechnology 01/2009; 157(3):431-41. · 1.94 Impact Factor
• Article: Biosynthesis of poly-3-hydroxybutyrate with a high molecular weight by methanotroph from methane and methanol

  Yingxin Zhang, Jiaying Xin, Linlin Chen, Hao Song, Chungu Xia
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  ABSTRACT: Poly-3-hydroxybutyrate (PHB) can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and plentiful not only as natural gas, but also as biogas. Methanol can also maintain methanotrophic activity in some conditions. The methanotrophic strain Methylosinus trichosporium IMV3011 can accumulate PHB with methane and methanol in a brief nonsterile process. Liquid methanol (0.1%) was added to improve the oxidization of methane. The studies were carried out using shake flasks. Cultivation was performed in two stages: a continuous growth phase and a PHB accumulation phase under the conditions short of essential nutrients (ammonium, nitrate, phosphorus, copper, iron (III), magnesium or ethylenediamine tetraacetate (EDTA)) in batch culture. It was found that the most suitable growth time for the cell is 144 h. Then an optimized culture condition for second stage was determined, in which the PHB concentration could be much increased to 0.6 g/L. In order to increase PHB content, citric acid was added as an inhibitor of tricarboxylic acid cycle (TCA). It was found that citric acid is favorable for the PHB accumulation, and the PHB yield was increased to 40% (w/w) from the initial yield of 12% (w/w) after nutrient deficiency cultivation. The PHB produced is of very high quality with molecular weight up to 1.5×106Da.
  Journal of Natural Gas Chemistry 17(1):103-109. · 1.35 Impact Factor