A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainages(AMDs)samples collected from several sulphide mines in China,and the bioleaching of chalcopyrite was conducted both in sha...A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainages(AMDs)samples collected from several sulphide mines in China,and the bioleaching of chalcopyrite was conducted both in shake flask and bioreactor.The results show that in the shake flask,the mixture can tolerate 50 g/L chalcopyrite after being acclimated to gradually increased concentrations of chalcopyrite.The copper extraction increases obviously in bioleaching of chalcopyrite with moderately thermophilic microorganisms supplemented with 0.4 g/L yeast extract at 180 r/min,74% copper can be extracted in the pulp of 50 g/L chalcopyrite after 20 d.Compared with copper extractions of mesophilic culture,unacclimated culture and acclimated culture without addition of yeast extract,that of accliniated culture with addition of yeast extract is increased by 53%,44% and 16%,respectively.In a completely stirred tank reactor,the mass fraction of copper and total iron extraction reach up to 81% and 56%,respectively.The results also indicate that it is necessary to add a large amount of acid to the pulp to extract copper from chalcopyrite effectively.展开更多
High salinity industrial wastewater is difficult to treat using biological treatment system because of the high concentrations of salt.The potential of a sequencing batch biofilm reactor(SBBR)process in treating synth...High salinity industrial wastewater is difficult to treat using biological treatment system because of the high concentrations of salt.The potential of a sequencing batch biofilm reactor(SBBR)process in treating synthetic high salinity wastewater was evaluated at laboratory scale during a 110-day operation.The reactor was operated in a 12 h cycle,and each cycle consisted of 0.25 h influent addition,8 h aeration,3 h anoxic reaction,0.5 h sedimentation and 0.25 h effluent withdrawal.Gradual increase in salinity gradient was applied during the acclimatization period.The acclimated SBBR system was demonstrated to be an effective process to remove organic compounds and ammonia nitrogen under high salinity conditions with chemical oxygen demand(COD)and ammonia nitrogen(NH3-N)removal efficiencies of 88% and 80%,respectively.The microscopic examination indicated that rather than rotifers or vorticella,the zoogloea,filamentous fungus mingled with a small quantity of swimming infusorians were dominant bacteria in SBBR system.The removal efficiencies close to 80% in COD and 75% in NH3-N were achieved at an organic loading rate(OLR)of 0.96 kg COD/(m3·d),pH of 7.0,salinity of 14 g/L and NH3-N of 30 mg/L.展开更多
Ammopiptanthus mongolicus is the only evergreen broadleaved shrub endemic species to the Alashan Desert, northwest sand area of China, and can survive at -30℃ or even lower temperature in winter. A modified solid-pha...Ammopiptanthus mongolicus is the only evergreen broadleaved shrub endemic species to the Alashan Desert, northwest sand area of China, and can survive at -30℃ or even lower temperature in winter. A modified solid-phase subtraction hybridization technique was developed to isolate and screen cDNAs, whose transcripts increased in cold-treated A. mongolicus seedlings. Sequence analysis of the screened clones indicated that 11 clones had coding regions, with four of them containing complete open reading frame. And nine of the 11 clones shared various degrees of homology with the genes found in the GenBank database and the other two were unidentified sequences. Sequence data further revealed that these accumulated transcripts encode three low molecular weight proteins, a late-embryogenesis protein and two cold acclimation responsive proteins; two photosynthesis-related proteins, photosystem I subunit II precursor (PsaD) and photosystem II oxygen-evolving complex 33kDa subunit (OEC33); a protease inhibitor; an adenosine triphosphatase and a 14-3-3 related protein. Analysis on the function of these proteins indicated that the low molecular weight proteins were associated with water holding ability of cytoplasm; photosynthesis-related proteins participated in the adjustments of photosynthetic apparatus to resist photoinhibition; 14-3-3 related protein could interact with adenosine triphosphatase to enhance ATPase activity and energy metabolism; and protease inhibitor involved in the prevention of unwanted cell death was caused by reactive oxygen species. We suggest that cold acclimation with low light intensity in A. mongolicus is a more complex interaction of low temperature, light, energy and signal than that assumed previously.展开更多
基金Project(50621063, 40646029) supported by the National Natural Science Foundation of ChinaProject (2004CB619204) supported by the National Basic Research Program
文摘A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainages(AMDs)samples collected from several sulphide mines in China,and the bioleaching of chalcopyrite was conducted both in shake flask and bioreactor.The results show that in the shake flask,the mixture can tolerate 50 g/L chalcopyrite after being acclimated to gradually increased concentrations of chalcopyrite.The copper extraction increases obviously in bioleaching of chalcopyrite with moderately thermophilic microorganisms supplemented with 0.4 g/L yeast extract at 180 r/min,74% copper can be extracted in the pulp of 50 g/L chalcopyrite after 20 d.Compared with copper extractions of mesophilic culture,unacclimated culture and acclimated culture without addition of yeast extract,that of accliniated culture with addition of yeast extract is increased by 53%,44% and 16%,respectively.In a completely stirred tank reactor,the mass fraction of copper and total iron extraction reach up to 81% and 56%,respectively.The results also indicate that it is necessary to add a large amount of acid to the pulp to extract copper from chalcopyrite effectively.
基金Projects(ZR2013BL010,ZR2012DL05)supported by the Natural Science Foundation of Shandong Province,ChinaProject(4041412016)supported by the Research Excellence Award of Shandong University of Technology,ChinaProjects(2013GG03116,2011GG02115)supported by the Science and Technology Development Planning Project of Zibo,China
文摘High salinity industrial wastewater is difficult to treat using biological treatment system because of the high concentrations of salt.The potential of a sequencing batch biofilm reactor(SBBR)process in treating synthetic high salinity wastewater was evaluated at laboratory scale during a 110-day operation.The reactor was operated in a 12 h cycle,and each cycle consisted of 0.25 h influent addition,8 h aeration,3 h anoxic reaction,0.5 h sedimentation and 0.25 h effluent withdrawal.Gradual increase in salinity gradient was applied during the acclimatization period.The acclimated SBBR system was demonstrated to be an effective process to remove organic compounds and ammonia nitrogen under high salinity conditions with chemical oxygen demand(COD)and ammonia nitrogen(NH3-N)removal efficiencies of 88% and 80%,respectively.The microscopic examination indicated that rather than rotifers or vorticella,the zoogloea,filamentous fungus mingled with a small quantity of swimming infusorians were dominant bacteria in SBBR system.The removal efficiencies close to 80% in COD and 75% in NH3-N were achieved at an organic loading rate(OLR)of 0.96 kg COD/(m3·d),pH of 7.0,salinity of 14 g/L and NH3-N of 30 mg/L.
文摘Ammopiptanthus mongolicus is the only evergreen broadleaved shrub endemic species to the Alashan Desert, northwest sand area of China, and can survive at -30℃ or even lower temperature in winter. A modified solid-phase subtraction hybridization technique was developed to isolate and screen cDNAs, whose transcripts increased in cold-treated A. mongolicus seedlings. Sequence analysis of the screened clones indicated that 11 clones had coding regions, with four of them containing complete open reading frame. And nine of the 11 clones shared various degrees of homology with the genes found in the GenBank database and the other two were unidentified sequences. Sequence data further revealed that these accumulated transcripts encode three low molecular weight proteins, a late-embryogenesis protein and two cold acclimation responsive proteins; two photosynthesis-related proteins, photosystem I subunit II precursor (PsaD) and photosystem II oxygen-evolving complex 33kDa subunit (OEC33); a protease inhibitor; an adenosine triphosphatase and a 14-3-3 related protein. Analysis on the function of these proteins indicated that the low molecular weight proteins were associated with water holding ability of cytoplasm; photosynthesis-related proteins participated in the adjustments of photosynthetic apparatus to resist photoinhibition; 14-3-3 related protein could interact with adenosine triphosphatase to enhance ATPase activity and energy metabolism; and protease inhibitor involved in the prevention of unwanted cell death was caused by reactive oxygen species. We suggest that cold acclimation with low light intensity in A. mongolicus is a more complex interaction of low temperature, light, energy and signal than that assumed previously.
