2.Surface display of phytase on Saccharomyces cerevisiae for efficient bioethanol production from corn starch.
Yan XIAO ; Xianzhong CHEN ; Wei SHEN ; Haiquan YANG ; You FAN
Chinese Journal of Biotechnology 2015;31(12):1700-1710
Production of bioethanol using starch as raw material has become a very prominent technology. However, phytate in the raw material not only decreases ethanol production efficiency, but also increases phosphorus discharge. In this study, to decrease phytate content in an ethanol fermentationprocess, Saccharomyces cerevisiae was engineered forheterologous expression of phytase on the cell surface. The phy gene encoding phytase gene was fused with the C-terminal-half region of α-agglutinin and then inserted downstream of the secretion signal gene, to produce a yeast surface-display expression vector pMGK-AG-phy, which was then transformed into S. cerevisiae. The recombinant yeast strain, PHY, successfully displayed phytase on the surface of cells producing 6.4 U/g wet cells and its properties were further characterized. The growthrate and ethanol production of the PHY strain were faster than the parent S. cerevisiae strain in the fermentation medium by simultaneous saccharification and fermentation. Moreover, the phytate concentration decreased by 91% in dry vinasse compared to the control. In summary, we constructed recombinant S. cerevisiae strain displaying phytase on the cell surface, which could effectively reduce the content of phytate, improve the utilization value of vinasse and reduce the discharge of phosphorus. The strain reported here represents a useful novel engineering platform for developing an environment-friendly system for bioethanol production from a corn substrate.
6-Phytase
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metabolism
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Biofuels
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Ethanol
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chemistry
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Fermentation
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Industrial Microbiology
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Saccharomyces cerevisiae
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metabolism
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Starch
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chemistry
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Zea mays
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chemistry
5.Apoptosis signaling pathway in a subtotal nephrectomy rat model.
Xiao, YANG ; Yanchung, SHEN ; Zhonghua, ZHU ; Anguo, DENG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2006;26(4):425-8
To investigate the role and mechanisms of apoptosis and apoptosis signaling pathway in 5/6 nephrectomy rat model (SN(x)), the mRNA and protein levels of caspase-3, -8, -9 and apoptosis were detected by in situ end labeling (TUNEL), immunohistochemistry, RT-PCR, Western-blotting 1, 2, 4, 8, 12, 16, 26 and 40 weeks after 5/6 nephrectomy rat model was made respectively. The rats in the model group developed glomerular sclerosis and renal interstitial fibrosis. The number of the apoptototic cells in glomeruli, renal tubule and renal interstitium was remarkably higher in the model group than that in the control group (P < 0.05, P < 0.01). Changes of mRNA and protein level of caspase-3, -8, -9 had the same tendency and was up-regulated wavily in the rat model compared with the control group (P < 0.05). Peaks in model appeared on the 4th and the 40th week respectively. The growth amplitude of caspase-9 was remarkably higher than that of caspase-8. It is concluded that the development of 5/6 nephrectomy rat model was correlated with the apoptosis of glomeruli, renal tubule and renal interstitium. Both of death receptor and mitochondria signaling pathways are involved in the process and the latter might play a primary role.
6.Effect of Metformin Therapy on Obese Nondiabetic Children with Hyperinsulinemia
pei-rong, YANG ; xiao-dong, HUANG ; yong-nian, SHEN
Journal of Applied Clinical Pediatrics 2004;0(08):-
Objective To explore the efficacy and safety of metformin therapy on obese nondiabetic children with hyperinsulinemia.Methods Twenty-two obese nondiabetic children with hyperinsulinemia were divided into two groups:control group(dietary counseling and exercise) and treatment group(dietary counseling and exercise combined with metformin).The changes of body mass index(BMI),fasting glucose(FPG),fasting insulin(FINS),insulin resistance(HOMA-IR),2 h PG,2 h INS,total cholesterol(TC) and triglyceride(TG),before and after treatment were determined,and the findings were compared and analyzed.Results After treatment,there were significant differences in BMI,TC,FINS,HOMA-IR levels(P0.05),except the BMI(P
7.Regulation mechanism of autophagy-related protein LC3 by c-Jun in methotrexate resistant human choriocarcinoma JEG-3 cells
Yun SHEN ; Yang XIANG ; Changji XIAO ; Jing ZHAO
Chinese Journal of Obstetrics and Gynecology 2014;(7):531-535
Objective To explore the regulation mechanism of autophagy-related protein, microtubule-associated protein 1 light chain 3 (LC3), via c-Jun in methotrexate resistant human choriocarcinoma JEG-3 cell lines. Methods Human choriocarcinoma JEG-3 cell lines, and methotrexate resistant choriocarcinoma JEG-3 (JEG-3/MTXR) cell lines were used in our present study. Phosphorylation c-Jun (p-c-Jun) was evaluated after exposure to 0.02 ng/ml methotrexate for 72 hours in both cells by western blot. c-Jun gene was knockdown by small interference RNA (siRNA) in JEG-3/MTXR cells, and LC3 was evaluated by western blot and reverse transcription-PCR. The binding of LC3 promoter with c-Jun protein was detected via chromatin immunoprecipitation assay (ChIP) with or without 0.02 ng/ml methotrexate exposure. Results The results showed that p-c-Jun was up-regulated after methotrexate treatment for 72 hours (1.99±0.20, versus 0.20±0.06 at 0 hour;P<0.05) by western blot analysis in JEG-3/MTXR cell lines. Further investigation demonstrated that c-Jun-siRNA could inhibit the up-regulation of LC3 formation and after methotrexate exposure (LC3 mRNA:1.24±0.17 versus 3.03±0.43;LC3 protein:0.52±0.07 verus 1.20± 0.15; all P<0.05). The binding of LC3 promoter by c-Jun protein was up-regulated after methotrexate treatment by the method of ChIP in methotrexate resistant JEG-3/MTXR cells [(2.95 ± 0.35) times]. Conclusion Autophagy-related gene LC3 expression regulated by c-Jun protein may be involved in the effect mechanism of the development of methotrexate resistance in choriocarcinoma JEG-3 cells.
8.Determination of Contents 3-amide-indole Derivative and Related Substances
Dongni SHEN ; Jianyun YANG ; Bingkun XIAO ; Rongqing HUANG
Herald of Medicine 2014;(5):650-652
Objective To establish a RP-HPLC method for the determination of 3-amide-indole derivative and its related substances. Methods Diamonsil C18(250 mmí4. 6 mm,5 μm) column was adopted. The mobile phase consisted of a mixture of methanol-acetonitrile-water(431245) at the flow rate of 1. 0 mL·min-1 . The wavelength for ultraviolet detection was 224 nm. The injection volume was 20 μL and the column temperature was room temperature. Results 3-amide-indole derivative and related substances could be well separated. The linearity of the 3-amide-indole derivative curve was well correlated (r=0. 999 7) within the range of 0. 04-0. 16 mg·mL-1. The RSD was 0. 52%with good repeatability. The detection limit was 2. 65 ng. Conclusion The method is accurate,reliable,sensitive and specific,which could be used for the determination of 3-amide-indolederivative and related substances.
9.Apoptosis and expression of apoptosis-related genes in kidneys of the rats with 5/6 nephrectomy
Xiao YANG ; Yanchun SHEN ; Zhonghua ZHU ; Anguo DENG ; Jianshe LIU
Chinese Journal of Pathophysiology 1989;0(05):-
AIM: To establish a model of subtotal nephrectomy (SNx) and investigate the changes of apoptosis and apoptosis-related genes (Bax, bcl-2, caspase-3, caspase-8 and caspase-9) in the rat remnant kidney. METHODS: Remnant kidneys were produced in adult male SD rats by 5/6 nephrectomy. The renal function and histopathological changes were evaluated at 1, 2, 4, 8, 12, 16, 26 and 40 weeks after operation. The tissues of remnant kidneys were collected to detect apoptosis cells by in situ end-labeling of cleaved DNA (TUNEL) and proliferating cells by determining the proliferating cell nuclear antigen (PCNA). The expression of Bax, bcl-2, caspase-3, caspase-8 and caspase-9 was measured by RT-PCR and Western blotting. The proteins were detected by immunohistochemistry staining. The relation between apoptosis, proliferation, glomerulosclerosis and renal interstitial fibrosis was also observed. RESULTS: The results showed the renal pathological dynamic changes in 5/6 nephrectomy remnant kidneys were tubule-interstitial inflammation and fibrosis, as well as glomerulosclerosis. There were transient increases in both proliferating and apoptotic processes in glomerulus, tubules and interstitium. Apoptosis was increased and most of apoptotic cells were detected in tubular epithelial cells and interstitial area. The mRNA and protein expression of Bax, caspase-3, caspase-8 and caspase-9 were increased in all course, and peaked at week 4 and 40 in the SNX rats. The successive changes of these parameters were parallel to the level of focal inflammation in interstitium. Glomerulosclerosis index was related with focal inflammation cells and 24 hours urine protein (r=0.788, 0.822; P
10.NOVEL ADVANCES ON PESTICIDES DEGRADATION BY MICROORGANISMS
Xiao-Hong YANG ; Jun LI ; Cheng GE ; De-Long SHEN ;
Microbiology 1992;0(06):-
Pesticides, especially chemistry pesticides with high toxicity, high residue, and difficult degradation are a kind of important environment pollutants and pesticide degradation by microorganisms is one of the powerful means to treat pesticide pollution. Many researchers conducted lots of studies on it. Types of pesticide degraders, construction of genetically engineered microorganisms, degrading mechanisms, degradation characteristics, influencing factors, applying effect and so on were summarized in this article. The research trend of degradation of pesticides by microorganisms and problems to be solved were also put forward.