ABSTRACT
To enhance biohydrogen production of Klebsiella sp. HQ-3, the global transcriptional factor (Fnr), formate dehydrogenase H (FDH1) and the pncB gene encoding the nicotinic acid phosphoribosyltransferase (NAPRTase) were for the first time over-expressed in Klebsiella sp. HQ-3. The fnr, fdhF, pncB genes were cloned from the genomic DNA of Klebsiella sp. HQ-3 by 3 pairs of universal primers, and introduced into the corresponding sites of the modified pET28a-Pkan, resulting in the plasmids pET28a-Pkan-fnr, pET28a-Pkan-fdhF and pET28a-Pkan-pncB. The 4 plasmids were then electroported into wild Klebsiella sp. HQ-3 to create HQ-3-fnr, HQ-3-fdhF, HQ-3-pncB and HQ-3-C, respectively. Hydrogen production was measured using a gas chromatograph and the metabolites were analyzed with a high-performance liquid chromatograph (HPLC). The results indicate that over-expression of fnr, fdhF and pncB significantly enhanced hydrogen production in the three recombinant strains. Hydrogen production per mol glucose for HQ-3 fnr, HQ-3 pncB, HQ-3 fdhF was 1.113, 1.106 and 1.063 mol of hydrogen/mol glucose, which was respectively increased by 12.26%, 11.62% and 7.28% compared with that of the control strain HQ-3-C (0.991 mol of hydrogen/mol glucose). Moreover, the analysis of HPLC showed that the concentrations of formate and lactate were markedly decreased, but succinate remained unchanged in culture media compared with those of the control strain HQ-3-C.
Subject(s)
Fermentation , Formate Dehydrogenases , Genetics , Hydrogen , Metabolism , Iron-Sulfur Proteins , Genetics , Klebsiella , Genetics , Metabolism , Metabolic Engineering , Methods , Metabolic Networks and Pathways , Pentosyltransferases , GeneticsABSTRACT
Objective To study the clinical characters,diagnosis and principles of treatmentof acute pancreatitis during pregnancy.Methods Forty-eight cases of acute pancreatitis during pregnancy treated in the recent 8 years were retrospectively analyzed,38 cases had non-surgical treatment(of which 36 cases were cured);10 cases had surgical treatment to remove necrotic tissue and mainly termination of pregnancy.Results Most of the cases in this group had simple pancreatitis,which accounted for 64.58%(31/48).There were 5 cases of maternal(10.42%) death and three cases of fetal(6.25%) death,and all were in patients with severe pancreatitis.Fatality rate of pregnant women with severe pancreatitis was 29.41%.Conclusions Acute pancreatitis during pregnancy is a serious disease with low prevalence rate,but has high fatality rate,and is the primary cause of death in acute abdomen of pregnancy.Nonoperative treatment is the first choice of treatment in this condition.In severe cases,timely surgical intervention is warranted,and the surgical indications should not be altered because of the pregnancy.The safety of both the pregnant woman and the fetus must simultaneously be kept into mind during therapy.
ABSTRACT
Objective To explore the effective therapeutic methods for hepatolithiasis.Methods We retrospectively analyzed the clinical material of 178 hepatolithiasis patients who underwent surgical therapy.Among the 178 patients,107 patients were treated with T-tube drainage(including 7 patients with left hepatic lobe or quadlrate lobe resection),and 71 patients were treated with bile duct-intestinal anastomosis(including 11 patients with left hepatic lobe or quadrate lobe resection).Results Recurrence rate of postoperative angiocholitis in the two groups was 49.5 % and 24 % respectively,and the reoperation rate was 28.7 % and 8 % respectively.Conclusions The key to prevent recurrent angiocholitis and reduce the reoperation rate is to relieve biliary tract stricture,remove the focus of infection and provide unobstructed bile duct drainage.