Objective To evaluate the effect of white rot fungus Phanerochaete chrysosporium on removal of gaseous chlorobenzene. Methods Fungal mycelium mixed with a liquid medium was placed into airtight bottles. A certain amou...Objective To evaluate the effect of white rot fungus Phanerochaete chrysosporium on removal of gaseous chlorobenzene. Methods Fungal mycelium mixed with a liquid medium was placed into airtight bottles. A certain amount of chlorobenzene was injected into the headspace of the bottles under different conditions. At a certain interval, the concentrations in the headspace were analyzed to evaluate the degradation of chlorobenzene by P. chrysosporium. Results The degradation effects of P. chrysosporium on chlorobenzene under different conditions were investigated. The difference in the optimum temperature for the growth of the fungi and chlorobenzene degradation was observed. The data indicated that a lower temperature (28℃) would promote the degradation of chlorobenzene than the optimum temperature for the growth of the fungi (37℃). A low nitrogen source concentration (30 mg N/L) had a better effect on degrading chlorobenzene than a high nitrogen source concentration (higher than 100 mg N/L). A high initial concentration (over 1100 mg/m3) of chlorobenzene showed an inhibiting effect on degradation by P chrysosporium. A maximum removal efficiency of 95% was achieved at the initial concentration of 550 mg/m3. Conclusion P. chrysosporium has a rather good ability to remove gaseous chlorobeuzene. A low nitrogen source concentration and a low temperature promote the removal of chlorobenzene by P. chrysosporium. However, a high initial chlorobenzene concentration can inhibit chlorobenzene degradation.展开更多
Alkaline pretreatment of straw materials prior to enzyme hydrolysis is a key step for bioconversion of lignocellulose to bioethanol and chemicals.Wastewater from the alkaline pretreatment process must be treated befor...Alkaline pretreatment of straw materials prior to enzyme hydrolysis is a key step for bioconversion of lignocellulose to bioethanol and chemicals.Wastewater from the alkaline pretreatment process must be treated before discharge to minimize its environmental impact.In this study,biotreatment of the wastewater from soda-pretreatment process of corn stover was investigated using fungus Z-6,and some indexes such as color,chemical oxygen demand(COD),and lignin content of wastewater before and after biotreatment were determined to assess the effect of the biotreatment.Results showed that fungus treatment could remove color up to approximately 72%after 2 d,and decrease COD and lignin content by about 63%and 60%,respectively after 3 d.The wastewater was fractionated using dynamic ultrafiltration method,and the changes in lignin contents of the effluent fractions with different molecular weights before and after biotreatment were analyzed.Some compounds produced by the fungus during treatment were identified using gas chromatography-mass(GC-MS)spectrometer,which revealed that depolymerization of lignin occurred during the biotreatment process.展开更多
The free enzyme extracted from WZ-I, which was identified as Fusarium LK. ex Fx, could effectively degrade chlorpyrifos, an organophosphate insecticide. The methods of immobilizing this free enzyme and determined its ...The free enzyme extracted from WZ-I, which was identified as Fusarium LK. ex Fx, could effectively degrade chlorpyrifos, an organophosphate insecticide. The methods of immobilizing this free enzyme and determined its degradation-related characteristics were investigated. The properties of the immobilized enzyme were compared with those of the free enzyme. The optimal immobilization of the enzyme was achieved in a solution of 30 g/L sodium alginate at 4℃ for 4-12 hr. The immobilized enzyme showed the maximal activity at pH 8.0, 45℃. The maximum initial rate and the substrate concentration of the immobilized enzyme were less than that of the free enzyme. The immobilized enzyme, therefore, had a higher capacity to withstand a broader range of temperatures and pH conditions than the free enzyme. With varying pH and temperatures, the immobilized enzyme was more active than the free enzyme in the degradation reaction. In addition, the immobilized enzyme exhibited only a slight loss in its initial activity, even after three repeated uses. The results showed that the immobilized enzyme was more resistant to different environmental conditions, suggesting that it was viable for future practical use.展开更多
To investigate the growth conditions of white-rot fungus and simulate its metabolism kinetic models, the rules how the factors such as biomass, culture fluid, pH value, glucose consumption and exopolysaccharides gener...To investigate the growth conditions of white-rot fungus and simulate its metabolism kinetic models, the rules how the factors such as biomass, culture fluid, pH value, glucose consumption and exopolysaccharides generation, etc., changed during the batch culture process of white-rot fungi by using an air-lift fermenter, as well as metabolic kinetics of white-rot fungi were studied. Based on Logistic equation, Luedeking-Piret equation and experimental data, the correlation model parameters of mycelia biomass, glucose consumption and exopolysaccharide generation were obtained and found to be change with time in metabolism process. Detailedly, μm=0.071 8 h-1,α= 0.831 8 g/(g·h), β= 0.002 g/(g·h), b1=0.016 3 g/(g·h) and b2=3.023 3 g/(g·h). Hence the mycelial growth kinetic model, exopolysaccharide generation kinetic model and substrate consumption kinetic model which describe fermentation process of white-rot fungi were established. Meanwhile, the experimental data were verified by this model, and a good fitting result with an average relative error less than 10% between the data obtained from experiments and the model was yielded. The results show that these models can predict the growth and metabolic rules of white-rot fungus, the fermentation process of exopolysaccharides and the kinetic mechanism of white-rot fungus accurately.展开更多
The present work studied the influence of glucose feeding on the ligninolytic enzyme production of Phanerochaete chrysosporium in a nitrogen-limited(C/N ratio is 56/8.8 mmol/L)medium.Several sets of shaking flask expe...The present work studied the influence of glucose feeding on the ligninolytic enzyme production of Phanerochaete chrysosporium 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)activ-ity was 2.5 times greater than that produced in cultures with-out glucose feeding.Furthermore,the glucose feeding mode in fed-batch culture was also investigated.Compared to cul-tures 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.展开更多
Metal ions and fiber are common compounds in the livestock and poultry manure,which will affect the fate of organic compounds in aqueous environment. However,limited research has addressed the effect of coexisting met...Metal ions and fiber are common compounds in the livestock and poultry manure,which will affect the fate of organic compounds in aqueous environment. However,limited research has addressed the effect of coexisting metal ions and fiber on the biodegradation of sulfonamide antibiotics. Accordingly, a compositing study was performed to assess the effect of metal ions(Fe3+and Cu2+) on the biodegradation of sulfadimethoxine sodium salt(SDM) in the presence of fiber. The enhanced adsorption of SDM onto fiber in the presence of metal ions can be attributed to the π+–π electron donor acceptor(EDA) interaction. The microbial(Phanerochaete chrysosprium) could easily attach onto fiber forming attached microbial, and the degradation rates of SDM of immobilized bacteria in the presence of Fe3 +were 100%, which were significantly higher than those of free bacteria(45%). This study indicates that Fe3 +and fiber could enhance the biodegradation of SDM. Fiber acts as adsorbent, carrier, and substrate which enhanced the removal of SDM.展开更多
The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated. ...The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated. A deadlock between the two mycelia rather than replacement of one fungus by another was observed on an agar medium. The laccase activity in crude enzyme extracts from interaction zones reached a maximum after a 5-day incubation, which was significantly higher than that from regions of T. versicolor or P. chrysosporium alone. The enhanced induction of laccase activity lasted longer in half nutrition than in normal nutrition. A higher potential to oxidize benzo[a]pyrene by a crude enzyme preparation extracted from the interaction zones was demonstrated. After a 48 hr incubation period, the oxidation of benzo[a]pyrene by crude enzyme extracts from interaction zones reached 26.2%, while only 9.5% of benzo[a]pyrene was oxidized by crude extracts from T. versicolor. The oxidation was promoted by the co-oxidant 2,2'-azinobis-3- ethylbenzthiazoline-6-sulphonate diammonium salt (ABTS). These findings indicate that the application of co-culturing of white-rot fungi in bioremediation is a potential ameliorating technique for the restoration of PAH-contaminated soil.展开更多
This paper discusses problems in bio-pulping, puts forward the resolution to these problems, and points out the advantages of bio-pulping and future development potential.
基金supported by the Hi-tech Research and Development Program of China (2004AA601061).
文摘Objective To evaluate the effect of white rot fungus Phanerochaete chrysosporium on removal of gaseous chlorobenzene. Methods Fungal mycelium mixed with a liquid medium was placed into airtight bottles. A certain amount of chlorobenzene was injected into the headspace of the bottles under different conditions. At a certain interval, the concentrations in the headspace were analyzed to evaluate the degradation of chlorobenzene by P. chrysosporium. Results The degradation effects of P. chrysosporium on chlorobenzene under different conditions were investigated. The difference in the optimum temperature for the growth of the fungi and chlorobenzene degradation was observed. The data indicated that a lower temperature (28℃) would promote the degradation of chlorobenzene than the optimum temperature for the growth of the fungi (37℃). A low nitrogen source concentration (30 mg N/L) had a better effect on degrading chlorobenzene than a high nitrogen source concentration (higher than 100 mg N/L). A high initial concentration (over 1100 mg/m3) of chlorobenzene showed an inhibiting effect on degradation by P chrysosporium. A maximum removal efficiency of 95% was achieved at the initial concentration of 550 mg/m3. Conclusion P. chrysosporium has a rather good ability to remove gaseous chlorobeuzene. A low nitrogen source concentration and a low temperature promote the removal of chlorobenzene by P. chrysosporium. However, a high initial chlorobenzene concentration can inhibit chlorobenzene degradation.
基金This study was financially supported by the Key research and development project of Shandong province,China(2019GSF107009,2019JZZY020223 and 2019JZZY020807).
文摘Alkaline pretreatment of straw materials prior to enzyme hydrolysis is a key step for bioconversion of lignocellulose to bioethanol and chemicals.Wastewater from the alkaline pretreatment process must be treated before discharge to minimize its environmental impact.In this study,biotreatment of the wastewater from soda-pretreatment process of corn stover was investigated using fungus Z-6,and some indexes such as color,chemical oxygen demand(COD),and lignin content of wastewater before and after biotreatment were determined to assess the effect of the biotreatment.Results showed that fungus treatment could remove color up to approximately 72%after 2 d,and decrease COD and lignin content by about 63%and 60%,respectively after 3 d.The wastewater was fractionated using dynamic ultrafiltration method,and the changes in lignin contents of the effluent fractions with different molecular weights before and after biotreatment were analyzed.Some compounds produced by the fungus during treatment were identified using gas chromatography-mass(GC-MS)spectrometer,which revealed that depolymerization of lignin occurred during the biotreatment process.
基金supported by the National Natural Science Foundation of China(No. 41071164,40801203,41001152)the Postdoctoral Science Foundation of China(No. 20080431215,200801418)
文摘The free enzyme extracted from WZ-I, which was identified as Fusarium LK. ex Fx, could effectively degrade chlorpyrifos, an organophosphate insecticide. The methods of immobilizing this free enzyme and determined its degradation-related characteristics were investigated. The properties of the immobilized enzyme were compared with those of the free enzyme. The optimal immobilization of the enzyme was achieved in a solution of 30 g/L sodium alginate at 4℃ for 4-12 hr. The immobilized enzyme showed the maximal activity at pH 8.0, 45℃. The maximum initial rate and the substrate concentration of the immobilized enzyme were less than that of the free enzyme. The immobilized enzyme, therefore, had a higher capacity to withstand a broader range of temperatures and pH conditions than the free enzyme. With varying pH and temperatures, the immobilized enzyme was more active than the free enzyme in the degradation reaction. In addition, the immobilized enzyme exhibited only a slight loss in its initial activity, even after three repeated uses. The results showed that the immobilized enzyme was more resistant to different environmental conditions, suggesting that it was viable for future practical use.
基金Supported by National Natural Sciences Foundation of China(40373044)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(05KJD610209)~~
文摘To investigate the growth conditions of white-rot fungus and simulate its metabolism kinetic models, the rules how the factors such as biomass, culture fluid, pH value, glucose consumption and exopolysaccharides generation, etc., changed during the batch culture process of white-rot fungi by using an air-lift fermenter, as well as metabolic kinetics of white-rot fungi were studied. Based on Logistic equation, Luedeking-Piret equation and experimental data, the correlation model parameters of mycelia biomass, glucose consumption and exopolysaccharide generation were obtained and found to be change with time in metabolism process. Detailedly, μm=0.071 8 h-1,α= 0.831 8 g/(g·h), β= 0.002 g/(g·h), b1=0.016 3 g/(g·h) and b2=3.023 3 g/(g·h). Hence the mycelial growth kinetic model, exopolysaccharide generation kinetic model and substrate consumption kinetic model which describe fermentation process of white-rot fungi were established. Meanwhile, the experimental data were verified by this model, and a good fitting result with an average relative error less than 10% between the data obtained from experiments and the model was yielded. The results show that these models can predict the growth and metabolic rules of white-rot fungus, the fermentation process of exopolysaccharides and the kinetic mechanism of white-rot fungus accurately.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20577028).
文摘The present work studied the influence of glucose feeding on the ligninolytic enzyme production of Phanerochaete chrysosporium 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)activ-ity was 2.5 times greater than that produced in cultures with-out glucose feeding.Furthermore,the glucose feeding mode in fed-batch culture was also investigated.Compared to cul-tures 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.
基金supported by the National Natural Science Foundation of China (No. 21477137)the Frontier Fields during the Thirteenth Five-Year Plan Period of the Institute of Soil Science, Chinese Academy of Sciences (No. ISSASIP 1658)the State Key Research & Development Program of China (No. 2016YFC0501309)
文摘Metal ions and fiber are common compounds in the livestock and poultry manure,which will affect the fate of organic compounds in aqueous environment. However,limited research has addressed the effect of coexisting metal ions and fiber on the biodegradation of sulfonamide antibiotics. Accordingly, a compositing study was performed to assess the effect of metal ions(Fe3+and Cu2+) on the biodegradation of sulfadimethoxine sodium salt(SDM) in the presence of fiber. The enhanced adsorption of SDM onto fiber in the presence of metal ions can be attributed to the π+–π electron donor acceptor(EDA) interaction. The microbial(Phanerochaete chrysosprium) could easily attach onto fiber forming attached microbial, and the degradation rates of SDM of immobilized bacteria in the presence of Fe3 +were 100%, which were significantly higher than those of free bacteria(45%). This study indicates that Fe3 +and fiber could enhance the biodegradation of SDM. Fiber acts as adsorbent, carrier, and substrate which enhanced the removal of SDM.
基金supported by the National Natural Science Foundation of China(No.41071210,20890111)the National High-Tech Research and Development(863) Program of China(No.2012AA06A203)+1 种基金the Provincial Natural Science Foundation of Zhejiang(No.R5100105)the Doctoral Fund of the Ministry of Education of China(No.J20091588)
文摘The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated. A deadlock between the two mycelia rather than replacement of one fungus by another was observed on an agar medium. The laccase activity in crude enzyme extracts from interaction zones reached a maximum after a 5-day incubation, which was significantly higher than that from regions of T. versicolor or P. chrysosporium alone. The enhanced induction of laccase activity lasted longer in half nutrition than in normal nutrition. A higher potential to oxidize benzo[a]pyrene by a crude enzyme preparation extracted from the interaction zones was demonstrated. After a 48 hr incubation period, the oxidation of benzo[a]pyrene by crude enzyme extracts from interaction zones reached 26.2%, while only 9.5% of benzo[a]pyrene was oxidized by crude extracts from T. versicolor. The oxidation was promoted by the co-oxidant 2,2'-azinobis-3- ethylbenzthiazoline-6-sulphonate diammonium salt (ABTS). These findings indicate that the application of co-culturing of white-rot fungi in bioremediation is a potential ameliorating technique for the restoration of PAH-contaminated soil.
文摘This paper discusses problems in bio-pulping, puts forward the resolution to these problems, and points out the advantages of bio-pulping and future development potential.