Transcriptional regulation of cytochrome P450 3A4 by four kinds of traditional Chinese medicines / 中国中药杂志

<p><b>OBJECTIVE</b>To screen a group of traditional Chinese medicines with effect on pregnane X receptor (PXR)-mediated transcription regulation of P450 3A4 (CYP3A4); and to study whether they can induce the expression of CYP3A4 with a dose, time-dependent manner.</p><p><b>METHOD</b>Transient cotransfection reporter gene assays were performed with pCI-hPXR-neo, pGL3-CYP3A4-Luc and beta-galactosidase expression plasmid in HepG2 cells.</p><p><b>RESULT</b>Rhizoma Curcumae, Atractylodes lancea, A. macrocaphala and Poria cocos could induce transcriptional expression of CYP3A4. In the dose-effect study, 24 h after induction, 500 mg x L(-1) Rhizoma Curcumae, A. lancea, A. macrocaphala and Poria cocos, respectively, could induce the CYP3A4 gene expression with (6.82 +/- 0.09), (6.76 +/- 0.20), (5.49 +/- 0.13) and (4.97 +/- 0.07) folds, as compared with 0.1% DMSO treated cells. In the time-effect study, 500 mg x L(-1) Rhizoma curcumae, A. lancea, A. macrocaphala and Poria cocos for 48 h could induce the CYP3A4 gene expression with (7.74 +/- 0.54), (7.34 +/- 0.10), (5.54 +/- 0.11) and (5.32 +/- 0.18) folds, compared with 0.1% DMSO treated cells.</p><p><b>CONCLUSION</b>Rhizoma Curcumae, A. lancea, A. macrocaphala and Poria cocos could induce the expression of CYP3A4 gene transcription through activating PXR.</p>

Study of Expression of Pneumococcal Surface Protein and Immunogenicity / 中国生物工程杂志

The specific fragment of Pneumococcal surface protein A(PspA)and Pneumococcal Surface Adhesin A(PsaA)gene was amplified by PCR from Streptococcus pneumonia 5 and Streptococcus pneumonia 19.The amplified fragnent of PspA and PsaA gene was ligated into pET-27b(+)vector and transformed into BL 21 E.coli for expression and obtain the expressive production of PspA and PsaA.Induced by IPTG,the expression level was as high as 75 % of the total disolube protein.The result showed that the recombinant plasmid could express a specific 75 kDa and 37 kDa fusion protein in E.coli BL 21,which showed the good immunogenicity and a broadly cross reactivity with the other serotypes.

Optimization of Saccharomyces cerevisiae sp.Strain by1.1b Culture Conditions for Efficient Biosynthesis of D-(-)-mandelate Dehydrogenase / 微生物学通报

The culture conditions of Saccharomyces cerevisiae sp.strain by 1.1 b were optimized for the production of D-(-)-mandelate dehydrogenase which is useful for the asymmetric bioreduction of benzoylformate to form D-(-)-mandelate.The optimum medium(per liter)consistes of 60 g peptone,30 g maltose, 0.5 g MgSO_4,0.01 g ZnSO_4,1.0 g KCl.After optimization of the culture medium,the enzyme production in shake flasks is enhanced from 2.56 to 20.21 U/L.The optimum fermentation conditions were determined as follows:medium volume 100 mL(i.e.,40%for a 250-mL shake flask),pH 6.5,inoculum size 10%,temperature 30℃,and cultivation time 25 h.

Study of Breeding Saccharomyces cerevisiae with Improved Temperature and Ethanol Tolerance by Genome Shuffling / 微生物学通报

By UV induced mutagenesis of protoplasts of Saccharomyces cerevisiae strain f4, f5 and f6, and screening on plates containing different concertration of ethanol at different temperature, we obtained improved strains, such as f4.2, f5.1, f6.2, f4.5. By using a DES to deal with all the improved strains, We obtained two mutants, f5.1.1 and f4.2.1,which have improved ethanol torlerance. We made use of genome shuffling to generate improved strains in this work. We shuffled twice these improved strains by protoplast fusion and finally obtained strains with higher temperature and ethanol tolerance. we also identified shuffled strains that produced more ethanol by shake-flask experments. At the 35℃, the ethanol yield of R24 strain got to 12.93% (W/V), and were almost 5% higher than that of stain f4.

OPTIMIZATION OF THE MEDIUM AND PROCESS PARAMETERS IN BATCH AMINOGLYCOSIDE ANTIBIOTIC JI-20A FERMENTATION / 微生物学通报

The medium and process parameters were optimized in batchaminoglycoside antibiotic JI-20A fennentation. The optimal medium consists mainly of comstarch 60g/L, peanut meal 30g/L, com slurry 8g/L, maltose 10g/L, inorganic compound and amylase moderate , methionin 1g/L and cobalt chloride 6?g/mL. It was significant to adjust medium pH after autoclaving and oxygenate the fennentation medium for the cell growth and JI-20A product.