Fragment containing the whole riboflavin(rib)operons of B.cereus ATCC14579 was detected from GenBank and annotated.The rib operon of ATCC14579 was cloned with Pn,its native promoter,or with P43,the vegetative growth p...Fragment containing the whole riboflavin(rib)operons of B.cereus ATCC14579 was detected from GenBank and annotated.The rib operon of ATCC14579 was cloned with Pn,its native promoter,or with P43,the vegetative growth promoter,into the plasmid.Expression analysis showed that heterologous rib operon was operative in B.subtilis.Integrative plasmid with P43-rib fragment was integrated into the chromosome of B.subtilis RH33,yielding transformant B.subtilis PY.With optimized medium components,4.3 g·L -1 of riboflavin was achieved in batch culture of B.subtilis PY,which was 27%enhancement compared to the host strain.Real-time reverse transcription polymerase chain reaction(RT-PCR)analysis indicated that the transcriptional level of ribA maintained 2.8-fold higher with the expression of herterologous rib operon.Furthermore,the stability of B.subtilis PY was increased form 45%to 87%.The high transcriptional level of rib gene and higher stability of B.subtilis PY could explain the increased riboflavin production.展开更多
Objective:To establish a rapid,specific and sensitive diagnostic technique for the human Toxoplasma gondii infection in the recipi-ents with allogeneic hematopoietic stem cell transplantation and discuss its clinical ...Objective:To establish a rapid,specific and sensitive diagnostic technique for the human Toxoplasma gondii infection in the recipi-ents with allogeneic hematopoietic stem cell transplantation and discuss its clinical significance.Methods:30 patients undergoing allogeneic hematopoietic stem cell transplantation were detected by using ELISA and PCR.Results:Among 30 recipients undergiong allogeneic hematopoietic stem cell transplantation,3 were positive for Toxoplasma gondiii antigen and 5 for surface antigen p43 gene with the positive rate being 13.3% and 16.67% respectively.20 healthy people(negative for anti-Tox antibody)were also tested by using ELISA and PCR.Conclusion:PCR is an accurate,relatively rapid,sensitive and specific method for detecting P43 gene of Toxoplasma gondii.Be-canuse PCR can be applied to a variety of different clinical samples,it can be considered as a valuable additional tool for identification of Toxoplasma gondii infections.展开更多
基金Supported by the National Natural Science Foundation of China（20536040） the State Key Development Program for Basic Research of China（2007CB707802） the Development Project of Science and Technology of Tianjin（05YFGZGX04500）
文摘Fragment containing the whole riboflavin(rib)operons of B.cereus ATCC14579 was detected from GenBank and annotated.The rib operon of ATCC14579 was cloned with Pn,its native promoter,or with P43,the vegetative growth promoter,into the plasmid.Expression analysis showed that heterologous rib operon was operative in B.subtilis.Integrative plasmid with P43-rib fragment was integrated into the chromosome of B.subtilis RH33,yielding transformant B.subtilis PY.With optimized medium components,4.3 g·L -1 of riboflavin was achieved in batch culture of B.subtilis PY,which was 27%enhancement compared to the host strain.Real-time reverse transcription polymerase chain reaction(RT-PCR)analysis indicated that the transcriptional level of ribA maintained 2.8-fold higher with the expression of herterologous rib operon.Furthermore,the stability of B.subtilis PY was increased form 45%to 87%.The high transcriptional level of rib gene and higher stability of B.subtilis PY could explain the increased riboflavin production.
文摘Objective:To establish a rapid,specific and sensitive diagnostic technique for the human Toxoplasma gondii infection in the recipi-ents with allogeneic hematopoietic stem cell transplantation and discuss its clinical significance.Methods:30 patients undergoing allogeneic hematopoietic stem cell transplantation were detected by using ELISA and PCR.Results:Among 30 recipients undergiong allogeneic hematopoietic stem cell transplantation,3 were positive for Toxoplasma gondiii antigen and 5 for surface antigen p43 gene with the positive rate being 13.3% and 16.67% respectively.20 healthy people(negative for anti-Tox antibody)were also tested by using ELISA and PCR.Conclusion:PCR is an accurate,relatively rapid,sensitive and specific method for detecting P43 gene of Toxoplasma gondii.Be-canuse PCR can be applied to a variety of different clinical samples,it can be considered as a valuable additional tool for identification of Toxoplasma gondii infections.
