Carbon foam—a kind of new engineering material as packing material was adopted in three biofilters with different pore dimensions and adapted autotrophic nitrite nitrobacteria to investigate the purification of nitri...Carbon foam—a kind of new engineering material as packing material was adopted in three biofilters with different pore dimensions and adapted autotrophic nitrite nitrobacteria to investigate the purification of nitric oxide (NO) in a gas stream. The biofilm was developed on the surface of carbon foams using nitrite as its only nitric source. The moisture in the filter was maintained by ultrasonic aerosol equipment which can minimize the thickness of the liquid film. The liquid phase nitrification test was conducted to determine the variability and the potential of performance among the three carbon foam biofilters. The investigation showed that during the NO2^-—N inlet concentration of 200 g·L^-1·min^-1 to 800 g·L^-1·min^-1, the 24PPC (pores per centimeter) carbon foam biofilter had the greatest potential, achieving the NO2^-—N removal efficiency of 94% to 98%. The 8PPC and 18PPC carbon foam biofilters achieved the NO2^-—N removal efficiency of 15% to 21% and of 30% to 40%, respectively. The potential for this system to remove NO from a gas stream was shown on the basis of a steady removal efficiency of 41% to 50% which was attained for the 24PPC carbon foam biofilter at specified NO inlet concentration of 66.97 mg·m^-3 to 267.86mg·m^-3 and an empty-bed residence time of 3.5 min.展开更多
In order to provide reference for probiotics application in aquaculture, Bacillus subtilis （A）, Streptococcus faecalis （B） and photosynthetic bacteria （C） were prepared according to the ratios of 9：1, 4：1, 1：...In order to provide reference for probiotics application in aquaculture, Bacillus subtilis （A）, Streptococcus faecalis （B） and photosynthetic bacteria （C） were prepared according to the ratios of 9：1, 4：1, 1：1, 1：4 and 1：9 with 10^5 cfu/ml as the unit of concentration into 15 mixed microecological preparations, and their effects on COD, ammonia nitrogen, nitrite nitrogen and sulfide in pond water were investigated. The results showed that the mixed preparation of B. subtilis and photosynthetic bacteria at a ratio of 1：4 had the best effect in treating COD （P〈0.05）, the mixed preparation of B. subtilis and S. faecalis at a ratio of 4：1 showed the best effect in treating ammonia nitrogen （P〈0.05）, the mixed preparation of S. faecalis and photosynthetic bacteria at a ratio of 4：1 showed the best effect in treating nitrite nitrogen （P〈0.05）, and the mixed preparation of Streptococcus faecalis and photosynthetic bacteria at a ratio of 9：1 had the best effect of reducing sulfide （P〈0.05）.展开更多
AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion ...AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion tags （glutathione S-transferase, GST; thioredoxin, Trx; maltose-binding protein, MBP）, which preferably contributes to increasing solubility and to facilitating the proper folding of heteroprotein, were used to acquire the soluble and functional expression of RBD protein in Escherichia coli （BL21（DE3） and Rosetta-gamiB （DE3） strains）. The receptor binding ability of the purified soluble RBD protein was then detected by ELISA and flow cytometry assay. RESULTS： RBD of SARS-Cov spike protein was expressed as inclusion body when fused as TrxA tag form in both BL21 （DE3） and Rosetta-gamiB （DE3） under many different cultures and induction conditions. And there was no visible expression band on SDS-PAGE when RBD was expressed as MBP tagged form. Only GST tagged RBD was soluble expressed in BL21（DE3）, and the protein was purified by AKTA Prime Chromatography system. The ELISA data showed that GST.RBD antigen had positive reaction with anti-RBD mouse monoclonal antibody 1A5. Further flow cytometry assay demonstrated the high efficiency of RBD＇s binding ability to ACE2 （angiotensin-converting enzyme 2） positive Vero E6 cell. And ACE2 was proved as a cellular receptor that meditated an initial-affinity interaction with SARS-Cov spike protein. The geometrical mean of GST and GST.RBD binding to Vero E6 cells were 77.08 and 352.73 respectively. CONCLUSION： In this paper, we get sufficient soluble N terminal GST tagged RBD protein expressed in EcoliBL21 （DE3）; data from ELISA and flow cytometry assay demonstrate that the recombinant protein is functional and binding to ACE2 positive Vero E6 cell efficiently. And the recombinant RBD derived from E.coli can be used to developing subunit vaccine to block S protein binding with receptor and to neutralizing SARS-Cov infection.展开更多
基金Supported by the National Natural Science Foundation of China (No. 20276070)the National 863 Project of China (No. 2002AA649310) the Natural Science Foundation of Zhejiang Province (No. 202084).
文摘Carbon foam—a kind of new engineering material as packing material was adopted in three biofilters with different pore dimensions and adapted autotrophic nitrite nitrobacteria to investigate the purification of nitric oxide (NO) in a gas stream. The biofilm was developed on the surface of carbon foams using nitrite as its only nitric source. The moisture in the filter was maintained by ultrasonic aerosol equipment which can minimize the thickness of the liquid film. The liquid phase nitrification test was conducted to determine the variability and the potential of performance among the three carbon foam biofilters. The investigation showed that during the NO2^-—N inlet concentration of 200 g·L^-1·min^-1 to 800 g·L^-1·min^-1, the 24PPC (pores per centimeter) carbon foam biofilter had the greatest potential, achieving the NO2^-—N removal efficiency of 94% to 98%. The 8PPC and 18PPC carbon foam biofilters achieved the NO2^-—N removal efficiency of 15% to 21% and of 30% to 40%, respectively. The potential for this system to remove NO from a gas stream was shown on the basis of a steady removal efficiency of 41% to 50% which was attained for the 24PPC carbon foam biofilter at specified NO inlet concentration of 66.97 mg·m^-3 to 267.86mg·m^-3 and an empty-bed residence time of 3.5 min.
基金Supported by Science and Technology Planning Project of Hunan Province(2012NK3097)Fund for Key Discipline Construction(Zoology)of Hunan Province during the"12thFive-Year Plan"(2015-007)+1 种基金Open Fund of Hunan Province Key Laboratory of Health Aquaculture and Processing(2015-011)Science and Technology Innovation Team Plan of Hunan Provincial Colleges and Universities(2014-031)~~
文摘In order to provide reference for probiotics application in aquaculture, Bacillus subtilis （A）, Streptococcus faecalis （B） and photosynthetic bacteria （C） were prepared according to the ratios of 9：1, 4：1, 1：1, 1：4 and 1：9 with 10^5 cfu/ml as the unit of concentration into 15 mixed microecological preparations, and their effects on COD, ammonia nitrogen, nitrite nitrogen and sulfide in pond water were investigated. The results showed that the mixed preparation of B. subtilis and photosynthetic bacteria at a ratio of 1：4 had the best effect in treating COD （P〈0.05）, the mixed preparation of B. subtilis and S. faecalis at a ratio of 4：1 showed the best effect in treating ammonia nitrogen （P〈0.05）, the mixed preparation of S. faecalis and photosynthetic bacteria at a ratio of 4：1 showed the best effect in treating nitrite nitrogen （P〈0.05）, and the mixed preparation of Streptococcus faecalis and photosynthetic bacteria at a ratio of 9：1 had the best effect of reducing sulfide （P〈0.05）.
文摘AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion tags （glutathione S-transferase, GST; thioredoxin, Trx; maltose-binding protein, MBP）, which preferably contributes to increasing solubility and to facilitating the proper folding of heteroprotein, were used to acquire the soluble and functional expression of RBD protein in Escherichia coli （BL21（DE3） and Rosetta-gamiB （DE3） strains）. The receptor binding ability of the purified soluble RBD protein was then detected by ELISA and flow cytometry assay. RESULTS： RBD of SARS-Cov spike protein was expressed as inclusion body when fused as TrxA tag form in both BL21 （DE3） and Rosetta-gamiB （DE3） under many different cultures and induction conditions. And there was no visible expression band on SDS-PAGE when RBD was expressed as MBP tagged form. Only GST tagged RBD was soluble expressed in BL21（DE3）, and the protein was purified by AKTA Prime Chromatography system. The ELISA data showed that GST.RBD antigen had positive reaction with anti-RBD mouse monoclonal antibody 1A5. Further flow cytometry assay demonstrated the high efficiency of RBD＇s binding ability to ACE2 （angiotensin-converting enzyme 2） positive Vero E6 cell. And ACE2 was proved as a cellular receptor that meditated an initial-affinity interaction with SARS-Cov spike protein. The geometrical mean of GST and GST.RBD binding to Vero E6 cells were 77.08 and 352.73 respectively. CONCLUSION： In this paper, we get sufficient soluble N terminal GST tagged RBD protein expressed in EcoliBL21 （DE3）; data from ELISA and flow cytometry assay demonstrate that the recombinant protein is functional and binding to ACE2 positive Vero E6 cell efficiently. And the recombinant RBD derived from E.coli can be used to developing subunit vaccine to block S protein binding with receptor and to neutralizing SARS-Cov infection.
