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Journal Article 3

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Phanerochaete chrysosporium 1

biological pretreatment 1

biorecalcitrance 1

carbon nanotubes 1

catalytic activity 1

enzyme production 1

fed-batch culture 1

hydrolysis yield 1

immobilization 1

inoculation 1

manganese peroxidases (MnP) 1

mmol/L 1

nitrogen-limited 1

solid state fermentation 1

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Noncovalent immobilization of MnP from on carbon nanotubes

Jiaxi LI , Xianghua WEN ,

Frontiers of Environmental Science & Engineering 2009, Volume 3, Issue 3, Pages 294-299 doi: 10.1007/s11783-009-0041-4

Abstract: Manganese peroxidases (MnP) from were adsorbed onto multi-walled carbon nanotubes (MWNT). Four different loadings of MnP on MWNTs were investigated, and the maximum enzyme loading of 47.5 µg/mg of MWNTs was obtained in 12 h. The adsorbed MnP showed a catalytic activity of up to 0.1 U/mg of the weight of the system of MnP/MWNTs, with 23% of its original activity retained. The AFM image of the adsorbed enzymes indicated that a layer of MnP covered the surface of the MWNTs and retained its original three-dimensional shape. Amino-based nonspecific interactions may play the dominant role in the adsorption of MnP on MWNTs.

Keywords： manganese peroxidases (MnP) Phanerochaete chrysosporium carbon nanotubes immobilization catalytic activity

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Biological pretreatment of corn stover by solid state fermentation of

Jian ZHANG, Xin REN, Wenqun CHEN, Jie BAO

Frontiers of Chemical Science and Engineering 2012, Volume 6, Issue 2, Pages 146-151 doi: 10.1007/s11705-012-1220-6

Abstract: Biological pretreatment is a promising way to overcome the biorecalcitrance of cleaving the supermolecular structure of lignocellulose by lignin degrading enzymes from microorganisms. Solid state fermentation of corn stover with the white-rot fungus was carried out and the efficiency of this pretreatment was evaluated. The enzymatic hydrolysis yield reached a maximum when the corn stover was biologically pretreated for nine days, and the hydrolysis yield decreased sharply if the solid state fermentation was carried out for more than nine days. A possible explanation for this sharp decrease is that not only the lignin degrading enzymes (LiP and MnP) were secreted, but also other metabolites, which were toxic or fatal to the hydrolysis enzymes resulting in the lower hydrolysis yield were generated during the prolonged period of biopretreatment. These results are useful to help determine the optimal timing and to understand the lignin structure and degradation mechanism in biological pretreatment processes.

Keywords： biological pretreatment Phanerochaete chrysosporium solid state fermentation biorecalcitrance

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Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaetechrysosporium

ZHOU Xiaoyan, WEN Xianghua, FENG Yan

Frontiers of Environmental Science & Engineering 2007, Volume 1, Issue 1, Pages 89-94 doi: 10.1007/s11783-007-0017-1

Abstract: The present work studied the influence of glucose feeding on the ligninolytic enzyme production of in a nitrogen-limited (C/N ratio is 56/8.8 mmol/L) medium. Several sets of shaking flask experiments were conducted. The results showed that 2 g/L glucose feeding on the first day of the culture (24 h after the inoculation) stimulated both fungal biomass growth and enzyme production. The manganese peroxidase (MnP) activity was 2.5 times greater than that produced in cultures without glucose feeding. Furthermore, the glucose feeding mode in fed-batch culture was also investigated. Compared to cultures with glucose feeding every 48 h, cultures with glucose feeding of 1.5 g/L (final concentration) every 24 h produced more enzymes. The peak and total yield of MnP activity were 2.7 and 3 times greater compared to the contrast culture, respectively, and the enzyme was kept stable for 4 days with an activity of over 200 U/L.

Keywords： enzyme production fed-batch culture nitrogen-limited inoculation mmol/L