1.Research Advance in Recombinant Expression of Microbial Lipases
China Biotechnology 2006;0(05):-
Microbial lipases have been widely used in traditional industries,as well as in emerging biocatalysed areas owing to their ability to catalyze a variety of reactions in aqueous and non-aqueous media.Therefore,it is very important to enhance amount of lipase production by recombinant overexpression for meeting market demand.A critical review of main and novel strategies which have been employed for recombinant expression of microbial lipases are presented,including codon optimization,fusion and co-expression,dual expression system based on hybrid promoters,homologous overexpression,cell surface displaying and high-throughput screening based on gene library of expression.These new technologies are gradually coming to the forefront in the recombinant expression of lipase,especially for cell surface displaying and high-throughput screening based on gene library of expression.Meanwhile,several recombinant expressions for representative microbial lipases were also introduced and discussed,which are available for consultation when attempting to overexpress any lipases by scientists and industrialists.
2.Advances in Solid-state Fermentation of Microbial Lipase
Xiao-Feng WANG ; Yun-Jun YAN ;
China Biotechnology 2006;0(01):-
Lipases have catalytic active in both aqueous phase and the non-aqueous phase and have a wide range of application in various industrial areas.However,the high cost of lipase production has restricted its extensive use in industry.Solid state fermentation possesses many advantages,such as low requirement for devices,low energy consumption,low production cost,little pollution to environment and easily being popularized,which have made it an important means in microbial production of lipases.Owing to the rapidly increased energy cost and the people's awareness of environmental protection,the solid state fermentation technique,which was regarded as low-tech in the past,has regained attention and developed rapidly since the 1990s.The production of lipase by SSF technique was reviewed.Mainly contents describe its characteristics,including physical and chemical factors and bioreactors.
3.Optimization of Lipase Production Conditions by Geotrichum candidum Y162 Using Single Factor-response Surface Methodology
Jin-Yong YAN ; Jiang-Ke YANG ; Yun-Jun YAN ;
China Biotechnology 2006;0(08):-
The fermentation conditions of lipase production by Geotrichum candidum Y162 were optimized. Initially, the most suitable carbon olive oil, nitrogen source soybean flour and NH4Cl, salt BaCl2 and MgCl2 were selected according to single factorial experiments respectively. Based on the result, screening methodology Plackett-Burman design was used to evaluate the effects of twelve factors related to lipase production and three statistically significant factors olive oil, BaCl2 and NH4Cl were selected. The path of steepest ascent was used to approach the optimal region of lipase production subsequently. Then, the optimal combined concentration for maximum enzyme activity were further optimized by response surface methodology and determined as follows: olive oil 2.35%, BaCl2 0.36%,and NH4Cl 4.69%.The optimization of culture conditions of G.candidum Y162 led to a 2.25-fold increase in lipase production relative to initial result 14.16 U/ml, which indicate that single factor in combination with response surface methodology is an effective method for optimization of lipase production conditions by G.candidum Y162.
4.Quantitative evaluation of the changes of left ventricular short axial strain in patients with atrial septal defect before and after the transcatheter closure by two-dimensional speckle tracking imaging
Yan DUAN ; Jun ZHANG ; Shengjun TUO ; Yun HU ; Ting ZHU
Chinese Journal of Ultrasonography 2015;(7):562-565
Objective To explore the short axial strain of left ventricle in patients with atrial septal defect(ASD)before and after the transcatheter closure by using two-dimensional speckle tracking imaging (2D-STI).Methods A total of 30 patients with ASD underwent echocardiography before and after the transcatheter closure.The procedure was performed to obtain the peak of circumferential strain(Sc)and radial stain(Sr)of left ventricle by 2D-STI.Thirty healthy volunteers were enrolled as controls.Results ①Compared with the control group,regional myocardial Sc of ASD group decreased(P <0.05).Sc of anterior septum (AS),anterior wall (AW),laterior wall (LW)and posterior wall (PW)increased (P <0.05)at 2-days after the transcatheter closure and those parameters were higher than control group.At the six-months after the transcatheter closure,those parameters reduced to the normal level (P <0.05).Sc of inferior wall (IW)and mid-posterior septum (MP-Sept)increased to the normal level at 2-days after the closure surgery (P <0.05).②Compared with control group,regional myocardial Sr of ASD group decreased(P <0.05 ) except PW,two-days after the transcatheter closure these parameters increased to the normal level.Sr of PW in ASD group increased compared with control group(P <0.05),and there were no statistical changes at 2-days after the transcatheter closure.Sr of PW in ASD decreased (P <0.05 )to normal level until 6-months after the transcatheter closure.③ Global circumferential strain (GCS)of left ventricular in ASD group were lower than control group (P <0.05 ).At two-days after undergoing transcatheter closure the GCS increased (P <0.05)and those parameters were higher than control group (P <0.05).Six-months after the transcatheter closure those parameters reduced to the normal level (P < 0.05 ).There were no statistical differences of left ventricular global radial strain (GRS)between control group and ASD group. However,the GRS of ASD group increased (P < 0.05 )and those parameters were higher than control group (P <0.05)after 2-days undergoing the transcatheter closure.At six-months after the transcatheter closure those parameters were reduced to normal level (P <0.05 ).Conclusions 2D-STI can quantitative evaluate left ventricular circumferential strain and radial strain in patients with ASD before and after the transcatheter closure.
6.Immobilized Lipases Cooperates to Catalyze Transesterification Reaction of Lard
Ying HUANG ; Huan GAO ; Hai ZHEN ; Yun-Jun YAN ;
China Biotechnology 2006;0(01):-
The transesterification reaction conditions of lard with methyl acetate with combined use of immobilized lipases as catalysts were conducted. Initially, according to single factorial experiments, the studies on Lipozyme TL IM and Novozym 435 respectively catalyzed transesterification of lard showed that the optimal parameters of transesterification reaction were: the molar ratio of methyl acetate to oil of 14∶1, 40% enzyme added based on oil weight, temperature 50℃. Combined use of Lipozyme TL IM and Novozym 435 was proposed further to improve the catalytic performance by the response surface method (RSM). Herein, a 5-level-3-factor central composite rotated design was employed to evaluate the effects of lipase loading, the proportion of the two lipases and amount of methyl acetate. The optimum conditions were as followings: 40% lipase loading based on oil weight, 50%/50% the proportion of lipases (Novozym 435/Lipozyme TL IM), and the molar ratio of methyl acetate to oil of 14∶1. And under the optimal conditions, the highest biodiesel yield of 97.6% could be attained, which was higher than the biodiesel yield with each single one of the two lipases. The results suggested that the technics of combined use of certain immobilized lipases catalyzed transesterification reaction of lard for biodiesel production with methyl acetate as the acyl acceptor could raise the FAME yield and save the production cost.
7.Optimization of Fermentation Conditions of Lipase Produced by Pseudomonas cepacia PCL-3
Xiao-Feng WANG ; Jiang-Ke YANG ; Yun-Jun YAN ;
China Biotechnology 2006;0(10):-
The fermentation conditions of alkaline lipase producing by Pseudomonas cepacia PCL-3 were optimized.Based on the analysis of single factorial experiments,dextrin was the most suitable carbon source,peptone and urea were the suitable compound nitrogen sources among the examined materials.Three significant factors(urea,inoculum and initial pH) were selected from the eight factors related to lipase production by Plaekett-Burman method,and were further optimized with response surface analysis.And then,steepest ascent procedures were applied to define the optimal response region of the three factors.The obtained optimal conditions were urea 0.15%,inoculum 3.05% and initial pH 8.38,under which conditions,the enzyme activity was improved from 25.37 U/ml to 48.88 U/ml,enhanced 1.93 folds.Starting from the flask conditions,the highest lipase activity of 47.69U/ml was achieved by batch fermentation in a 10 L fermentor after 52 h of the cultivation.
8.Comparison of surface roughness and bacterial adhesion on zirconia ceramics and titanium alloys
Enlong JIN ; Yan-Jun JIAO ; Shu-Yun MENG ; Jue WANG ;
Chinese Journal of Tissue Engineering Research 2007;0(49):-
0.05).But the amount of adhered bacteria of surface-polished with titanium alloy is greater than that of surface-polished with zirconia ceramics(P
9.Effect of compound Chinese traditional medicine PC-SPES II in inhibiting proliferation of human prostate cancer cell LNCaP and on expressions of AR and PSA.
Bi-yan ZHANG ; Yu-feng LI ; Yun LAI ; Yun-sen LI ; Zi-jun CHEN
China Journal of Chinese Materia Medica 2015;40(5):950-956
To investigate the effect of compound Chinese traditional medicine PC-SPES II I in inhibiting proliferation of human prostate cancer cell LNCaP based on the androgen receptor (AR) signaling pathway. The effect of PC-SPES II on LNCaP cell proliferation was detected by MTT assay. According to the findings, at the mass concentration of 180-1 440 mg x L(-1), PC-SPES II significantly inhibited the proliferation of LNCaP cells; the IC50 of PC-SPES II at 24 h and 48 h were 311.48, 199.01 mg x L(-1), respectively. The flow Cytometry detection showed 240 mg x L(-1) PC-SPES II arrested cells in G2/M phase, and an obvious apoptotic peak appeared before G0/G1 peak and rose over time. Meanwhile, Hoechst 33258 staining revealed apoptotic cellular morphology. Annexin V-FITC/PI staining manifested an increase in apoptotic cell ratio at the PC-SPES II concentration of 480 mg x L(-1) in a dose dependent manner. The prostate specific antigen (PSA) secretion of LNCaP cells was tested by PSA ELISA kit. Besides, compared with 25 mg x L(-1) Bic, 480 mg x L(-1) PC-SPES II significantly reduced the cell secretion of PSA. The AR and PSA mRNA and protein expressions were detected by qRT-PCR and Western blot. According to the results, after the induction of LNCaP cells with synthetic androgen 25 μg x L(-1) R1881, 240-480 mg x L(-1) PC-SPES II notably down-regulated the AR and PSA mRNA and protein expressions and inhibited the translocation of AR from cytoplasm to nucleus. In summary, PC-SPES II significantly can inhibit the in vitro proliferation of LNCaP cells and arrest cell cycle arrest in G2/M phase. Its mechanism may be associated with the down-regulation of the AR and PSA expressions and the inhibition of AR nuclear translocation.
Antineoplastic Agents, Phytogenic
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pharmacology
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Cell Line, Tumor
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Cell Proliferation
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drug effects
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Drugs, Chinese Herbal
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pharmacology
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Humans
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Male
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Prostate-Specific Antigen
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genetics
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metabolism
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Prostatic Neoplasms
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drug therapy
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genetics
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metabolism
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physiopathology
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Receptors, Androgen
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genetics
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metabolism
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Signal Transduction
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drug effects
10.Protective effect of aluminum on hair loss induced by fluoride in fluorosis mice
Jun-rui, PEI ; Bing-yun, LI ; Yan-hui, GAO ; Ling-wang, ZHOU ; Dian-jun, SUN
Chinese Journal of Endemiology 2013;(2):136-139
Objective To investigate the effect of aluminum on hair loss induc ed by fluoride in fluorosis mice.Methods Sixty male C57BL mice were divided into four groups according to body mass:control group,fluoride (F) group (F-100 mg/L),aluminum(Al) group(Al3+ 270 mg/L) and F + Al group(F-100 mg/L + Al3+270 mg/L).Mice were killed 1 month and 3 months after the experiment,respectively.Bone F content was detected by ion-selective electrode method.The level of bone Al was measured through inductively coupled plasma emission spectrum.Dental fluorosis and hair loss of mice were evaluated by visual method.Results One month after the experiment,no dental fluorosis and hair loss was found in all four groups.The content of bone F was the highest in F group [(2401.649 + 86.835) mg/kg],and the lowest in A1 group [(427.006 + 11.878) mg/kg].The levels of bone F in F + Al group and control group were (1210.332 + 19.531)mg/kg and (538.001 + 33.337)mg/kg,respectively.The difference was statistically significant between any two groups (all P < 0.05).Three month after the experiment,all mice of F treatment group had dental fluorosis and hair loss(10/10).Alopecia areas were found in the neck and back regions only.There was no hair loss in control group,Al group and F + Al group.No dental fluorosis was found in both control and Al groups.Only 2 mice were found with dental fluorosis in F + Al group.The levels of bone F in F group,F + Al group,control group and Al group were (4098.645 + 58.842),(1888.165 ± 12.187),(876.258 + 14.462) and (662.385 ± 8.966) mg/kg,respectively.The difference was statistically significant between any two groups (all P < 0.05).Conclusions The hair loss is found in fluorosis mice.Hair loss of mice is closely associated with the level of F exposure.Al can prevent the occurrence of hair loss induced by F in mice through reducing the accumulation of F.