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101.
Wiluk Chacuttayapong Harumi Enoki Yusei Nabetani Minami Matsui Taichi Oguchi Reiko Motohashi 《Plant Biotechnology》2021,38(2):247
The development of green energy is important to mitigate global warming. Jatropha (Jatropha curcas L.) is a promising candidate for the production of alternative biofuel, which could reduce the burden on the Earth’s resources. Jatropha seeds contain a large quantity of lipids that can be used to produce biofuel, and the rest of the plant has many other uses. Currently, techniques for plant genetic transformation are extensively employed to study, create, and improve the specific characteristics of the target plant. Successful transformation involves the alteration of plants and their genetic materials. The aim of this study was to generate Jatropha plants that can support biofuel production by increasing their seed size using genes found via the rice FOX-hunting system. The present study improved previous protocols, enabling the production of transgenic Jatropha in two steps: the first step involved using auxins and dark incubation to promote root formation in excised shoots and the second step involved delaying the timing of antibiotic selection in the cultivation medium. Transgenic plants were subjected to PCR analysis; the transferred gene expression was confirmed via RT-PCR and the ploidy level was investigated. The results suggest that the genes associated with larger seed size in Arabidopsis thaliana, which were found using the rice FOX-hunting system, produce larger seeds in Jatropha. 相似文献
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Sen Li Xiang-Hong Ou Liang Wei Zhen-Bo Wang Qing-Hua Zhang Ying-Chun Ouyang Yi Hou Heide Schatten Qing-Yuan Sun 《Cell cycle (Georgetown, Tex.)》2012,11(17):3211-3218
Septin 7 is a conserved GTP-binding protein. In this study, we examined the localization and functions of Septin 7 during mouse oocyte meiotic maturation. Immunofluorescent analysis showed that intrinsic Septin 7 localized to the spindles from the pro-MI stage to the MII stage. Knockdown of Septin 7 by siRNA microinjection caused abnormal spindles and affected extrusion of the first polar body. Septin 7 mRNA tagged with myc was injected into GV stage oocytes to overexpress Septin 7. Overexpressed Myc-Septin 7 localized to the spindle and beneath the plasma membrane displaying long filaments. Fluorescence intensity of spindle α-tubulin in myc-Septin 7-injected oocytes was weaker than that of the control group, demonstrating that Septin 7 may influence recruitment of α-tubulin to spindles. MII oocytes injected with myc-Septin 7 exhibited abnormal chromosome alignment, and parthenogenetic activation failed to allow extrusion of the second polar body, suggesting that overexpression of Septin 7 may affect extrusion of the polar body by disturbing the alignment of chromosomes and regulating α-tubulin recruitment to spindles. In summary, Septin 7 may regulate meiotic cell cycle progression by affecting microtubule cytoskeletal dynamics in mouse oocytes. 相似文献
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Daisuke Miura Kohei Sugiyama Atsushi Ito Ayumi Ohba-Tanaka Mizuki Tanaka Takahiro Shintani 《Bioscience, biotechnology, and biochemistry》2018,82(10):1840-1848
For strain improvement of Aspergillus oryzae, development of the transformation system is essential, wherein dominant selectable markers, including drug-resistant genes, are available. However, A. oryzae generally has a relatively high resistance to many antifungal drugs effective against yeasts and other filamentous fungi. In the course of the study, while investigating azole drug resistance in A. oryzae, we isolated a spontaneous mutant that exhibited high resistance to azole fungicides and found that pleiotropic drug resistance (PDR)-type ATP-binding cassette (ABC) transporter genes were upregulated in the mutant; their overexpression in the wild-type strain increased azole drug resistance. While deletion of the gene designated atrG resulted in increased azole susceptibility, double deletion of atrG and another gene (atrA) resulted in further azole hypersensitivity. Overall, these results indicate that the ABC transporters AtrA and AtrG are involved in azole drug resistance in A. oryzae. 相似文献
106.
Concomitant reduction of lactate and ammonia accumulation in fed‐batch cultures: Impact on glycoprotein production and quality 下载免费PDF全文
Eric Karengera Anna Robotham John Kelly Yves Durocher Gregory De Crescenzo Olivier Henry 《Biotechnology progress》2018,34(2):494-504
Lactate and ammonia accumulation is a major factor limiting the performance of fed‐batch strategies for mammalian cell culture processes. In addition to the detrimental effects of these by‐products on production yield, ammonia also contributes to recombinant glycoprotein quality deterioration. In this study, we tackled the accumulation of these two inhibiting metabolic wastes by culturing in glutamine‐free fed‐batch cultures an engineered HEK293 cell line displaying an improved central carbon metabolism. Batch cultures highlighted the ability of PYC2‐overexpressing HEK293 cells to grow and sustain a relatively high viability in absence of glutamine without prior adaptation to the culture medium. In fed‐batch cultures designed to maintain glucose at high concentration by daily feeding a glutamine‐free concentrated nutrient feed, the maximum lactate and ammonia concentrations did not exceed 5 and 1 mM, respectively. In flask, this resulted in more than a 2.5‐fold increase in IFNα2b titer in comparison to the control glutamine‐supplied fed‐batch. In bioreactor, this strategy led to similar reductions in lactate and ammonia accumulation and an increase in IFNα2b production. Of utmost importance, this strategy did not affect IFNα2b quality with respect to sialylation and glycoform distribution as confirmed by surface plasmon resonance biosensing and LC‐MS, respectively. Our strategy thus offers an attractive and simple approach for the development of efficient cell culture processes for the mass production of high‐quality therapeutic glycoproteins. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:494–504, 2018 相似文献
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Ergosterol is an economically important metabolite produced by fungi. Recombinant Saccharomyces cerevisiae YEH56(pHXA42) with increased capacity of ergosterol formation was constructed by combined overexpression of sterol C-24(28)
reductase and sterol acyltransferase in the yeast strain YEH56. The production of ergosterol by this recombinant strain using
cane molasses (CM) as an inexpensive carbon source was investigated. An ergosterol content of 52.6 mg/g was obtained with
6.1 g/l of biomass from CM medium containing 60 g/l of total sugar in 30 h in shake flask. The ergosterol yield was enhanced
through the increasing cell biomass by supplementation of urea to a concentration of 6 g/l in molasses medium. Fermentation
was performed in 5-l bioreactor using the optimized molasses medium. In batch fermentation, the effect of agitation velocity
on ergosterol production was examined. The highest ergosterol yield was obtained at 400 rpm that increased 60.4 mg/l in comparison
with the shake flask culture. In fed-batch fermentation, yeast cells were cultivated, firstly, in the starting medium containing
molasses with 20 g/l of total sugar, 1.68 g/l of phosphate acid, and 6 g/l of urea (pH 5.4) for 5 h, then molasses containing
350 g/l of total sugar was fed exponentially into the bioreactor to keep the ethanol level in the broth below 0.5%. After
40 h of cultivation, the ergosterol yield reached 1,707 mg/l, which was 3.1-fold of that in the batch fermentation. 相似文献
110.
Förster A Jacobs K Juretzek T Mauersberger S Barth G 《Applied microbiology and biotechnology》2007,77(4):861-869
The yeast Yarrowia lipolytica secretes high amounts of various organic acids, like citric (CA) and isocitric (ICA) acids, triggered by growth limitation
caused by different factors and an excess of carbon source. Depending on the carbon source used, Y. lipolytica strains produce a mixture of CA and ICA in a characteristic ratio. To examine whether the CA/ICA product ratio can be influenced
by gene-dose-dependent overexpression or by disruption of the isocitrate lyase (ICL)-encoding gene ICL1, recombinant Y. lipolytica strains were constructed, which harbour multiple ICL1 copies or a defective icl1 allele. The high-level expression of ICL in ICL1 multicopy integrative transformants resulted in a strong shift of the CA/ICA ratio into direction of CA. On glycerol, glucose
and sucrose, the ICA proportion decreased from 10–12% to 3–6%, on sunflower oil or hexadecane even from 37–45% to 4–7% without
influencing the total amount of acids (CA and ICA) produced. In contrast, the loss of ICL activity in icl1-defective strains resulted in a moderate 2–5% increase in the ICA proportion compared to ICL wild-type strains on glucose
or glycerol. 相似文献