The nitrogen source requirements for riboflavin production by ccpA mutant Bacillus subtilis 24A1/pMX45 were optimized using linear regression. The optimal medium components considered included 8% glucose as carbon sou...The nitrogen source requirements for riboflavin production by ccpA mutant Bacillus subtilis 24A1/pMX45 were optimized using linear regression. The optimal medium components considered included 8% glucose as carbon source, 2% yeast powder, 0.05% MgSO4 ·7H2O, and four types of nitrogen sources : 0.1% yeast extract, 2% soybean powder, 1% corn plasm, and 0.2% ( NH4 ) 2 HPO4 in shake flask tests. Predictive ellipsoid was applied to determining the response values under the optimal levels for riboflavin production and glucose consumption. The optimal concentrations of the four types of nitrogen sources can remedy ammonium assimilative defection of ccpA mutant. Under the optimal conditions, the riboflavin yield increases to more than 5.0 g/L and 8%, glucose can be consumed completely after 60 h.展开更多
Objective This study aimed to investigate the possible role of Orphanin FQ(OFQ) in the regulation of hypothalamic gonadotropin-releasing hormone(GnRH) secretion. Methods The method of push-pull perfusion and radioimmu...Objective This study aimed to investigate the possible role of Orphanin FQ(OFQ) in the regulation of hypothalamic gonadotropin-releasing hormone(GnRH) secretion. Methods The method of push-pull perfusion and radioimmunoassay(RIA) were adopted to examine the secretory profile of GnRH in the median eminence(ME) in freely moving ovariectomized(OVX) rats after intracerebroventricular(icv) injection of OFQ and/or [Nphe1]NC(1-13)NH2(NC13),a competitive antagonists of the opioid receptor-like 1 receptor(ORL1 recep...展开更多
文摘The nitrogen source requirements for riboflavin production by ccpA mutant Bacillus subtilis 24A1/pMX45 were optimized using linear regression. The optimal medium components considered included 8% glucose as carbon source, 2% yeast powder, 0.05% MgSO4 ·7H2O, and four types of nitrogen sources : 0.1% yeast extract, 2% soybean powder, 1% corn plasm, and 0.2% ( NH4 ) 2 HPO4 in shake flask tests. Predictive ellipsoid was applied to determining the response values under the optimal levels for riboflavin production and glucose consumption. The optimal concentrations of the four types of nitrogen sources can remedy ammonium assimilative defection of ccpA mutant. Under the optimal conditions, the riboflavin yield increases to more than 5.0 g/L and 8%, glucose can be consumed completely after 60 h.
基金supported by the National Natural Science Foundation of China (No. 39870914)the Key Project on Traditional Chinese Medicine of Shanghai Medical Health Bureau (No. 20003).
文摘Objective This study aimed to investigate the possible role of Orphanin FQ(OFQ) in the regulation of hypothalamic gonadotropin-releasing hormone(GnRH) secretion. Methods The method of push-pull perfusion and radioimmunoassay(RIA) were adopted to examine the secretory profile of GnRH in the median eminence(ME) in freely moving ovariectomized(OVX) rats after intracerebroventricular(icv) injection of OFQ and/or [Nphe1]NC(1-13)NH2(NC13),a competitive antagonists of the opioid receptor-like 1 receptor(ORL1 recep...