Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
α-Glucosidase Inhibitory Activities of Lutein and Zeaxanthin Purified from Green Alga Chlorella ellipsoidea α-Glucosidase Inhibitory Activities of Lutein and Zeaxanthin Purified from Green Alga Chlorella ellipsoidea  [PDF]
QI Jia,KIM Sang Moo
- , 2018,
Abstract: α-Glucosidase inhibitors are used therapeutically to treat type-2 diabetes mellitus. Through a bioassay-guided fractionation technique, three carotenoids,(all-E)-lutein,(all-E)-zeaxanthin and(9-Z)-zeaxanthin, were purified from the green alga Chlorella ellipsoidea, in which(all-E)-lutein and(9-Z)-zeaxanthin had potent α-glucosidase inhibitory activity. IC_(50) values of(all-E)-lutein and(9-Z)-zeaxanthin were 70 and 53.5 μmol L~(-1) against Saccharomyces cerevisiae α-glucosidase, respectively, with non-competitive inhibition. In addition, IC_(50) values of(9-Z)-zeaxanthin against Bacillus stearothermophilus and rat-intestinal α-glucosidase were 805.1 and 671.2 μmol L~(-1), respectively. The K_i values of(all-E)-lutein and(9-Z)-zeaxanthin against S. cerevisiae α-glucosidase were 78.1 and 16.5 μmol L~(-1), respectively. Therefore, C. ellipsoidea carotenoids might be utilized as a novel candidate to prevent type-2 diabetes mellitus related disorders in food and medical industry
A Study on the Culture of Chlorella ellipsoidea in Various Concentrations of Unripe Tomato Juice Media  [PDF]
B. Mondal,M.R. Rahman,M.J. Alam,A.R. Tarafder
Pakistan Journal of Biological Sciences , 2005,
Abstract: The experiment was conducted to evaluate the performance of organic nutrients of Unripe Tomato Juice (URTJ) added with 0.2 g L-1 urea and Bold Basal Medium (BBM) as standard, for growing of C. ellipsoidea in laboratory condition for three months. C. ellipsoidea was cultured four different concentrations such as 0.7, 1.4, 2.8 and 4.15 g L-1 URTJ with added 0.2 g L-1 urea and Bold Basal Medium for a period of 16 days. The initial cell density of C. elliposidea was 2.90x mL-1, which attained a maximum cell density of 108.03x mL-1 in BBM followed by 75.24x, 69.67x, 54.80xand 27.35x mL-1 in 2.8, 1.4, 0.7 and 4.15 g L-1 of URTJ media with added 0.2 g L-1 urea, respectively on the 12th day of culture. Similar trend was observed in case of optical density of C. ellipsoidea. The proximate composition of C. ellipsoidea cultured in URTJ media was analyzed and found that the ranges of crude protein, crude lipid, ash and moisture ranged from 22.39-39.91%, 3.66-5.19%, 10.10-11.11% and 8.15-9.45%, respectively. Results showed that growth of C. ellipsoidea was significantly (p<0.05) higher in the concentrations of 2.8 g L-1 of URTJ with added 0.2 g L-1 urea than other concentrations (0.7, 1.4 and 4.15 g L-1) of URTJ with added urea at the temperature of 29.04°C, dissolved oxygen of 5.71 mg L-1, pH of 8.08 and light intensity of 1583 luxm-2s-1
Expression of Rabbit Neutrophile Peptide-1 in Nitrate Reductase- deficient Mutant of Chlorella ellipsoidea

ZHANG Xiao-Yu,WANG Peng,ZHAO Shi-Min,LI Xia,SHEN Xin,SUN Yong-Ru,CHU Cheng-Cai,WANG Yi-Qin,
,王 鹏,赵世民,李 霞,沈 昕,孙勇如,储成才,王义琴

遗传 , 2006,
Abstract: Application of transgenic Cholrella as bioreactor to express rabbit neutrophile pepetide-1 (NP-1) shows great practical value. In this paper, an NP-1 expression vector containing two selective marker genes NPTII and nitrate reductase gene was constructed. The NP-1 gene was transformed into the nitrate reductase-deficient mutant nrm-4 of Chlorella ellipsoidea via electroporation, and the transgenic alga expressed the active NP-1 were obtained.
A New Strategy to Produce a Defensin: Stable Production of Mutated NP-1 in Nitrate Reductase-Deficient Chlorella ellipsoidea  [PDF]
Li-Li Bai, Wei-Bo Yin, Yu-Hong Chen, Li-Li Niu, Yong-Ru Sun, Shi-Min Zhao, Fu-Quan Yang, Richard R.-C. Wang, Qing Wu, Xiang-Qi Zhang, Zan-Min Hu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054966
Abstract: Defensins are small cationic peptides that could be used as the potential substitute for antibiotics. However, there is no efficient method for producing defensins. In this study, we developed a new strategy to produce defensin in nitrate reductase (NR)-deficient C. ellipsoidea (nrm-4). We constructed a plant expression vector carrying mutated NP-1 gene (mNP-1), a mature α-defensin NP-1 gene from rabbit with an additional initiator codon in the 5′-terminus, in which the selection markers were NptII and NR genes. We transferred mNP-1 into nrm-4 using electroporation and obtained many transgenic lines with high efficiency under selection chemicals G418 and NaNO3. The mNP-1 was characterized using N-terminal sequencing after being isolated from transgenic lines. Excitingly, mNP-1 was produced at high levels (approximately 11.42 mg/l) even after 15 generations of continuous fermentation. In addition, mNP-1 had strong activity against Escherichia coli at 5 μg/ml. This research developed a new method for producing defensins using genetic engineering.
Chlorella high density training and lipid extraction condition optimizing

LI Jin-Sui,WANG Ping,DONG Li-Ming,

微生物学通报 , 2012,
Abstract: Objective] Chlorella high density training and lipid extraction condition optimizing. Methods] Single factor experiments were used to research different mediums and environmental factors on Chlorella cell growth effects, and the ultrasonic extraction method was employed by orthogonal experiment for algae powder oil extraction conditions. Results] The optimal condition of Chlorella ellipsoidea Y4 under heterotrophic culture to get high biomass were: BG11 medium with 50 g/L of glucose as the carbon source and 2 g/L KNO3 as the nitrogen source. The optimum culture temperature, shaking rate and the inoculums size were 29 °C, 180 r/min and 20%. By inoculating the preculture to a fermentation tank of 1 L capacity, we got dry cell weight 18.25 g/L. Based on the oil extraction condition optimization, Y4 lipid extraction yield increased from 25% to 60.2%, with lipid extraction yield raised by 35.2%. Conclusion] Optimization of chlorella culture conditions and lipid extraction conditions were studied, and the result promoted the exploitation and utilization of chlorella resources.
Antimalarial Iron Chelator, FBS0701, Shows Asexual and Gametocyte Plasmodium falciparum Activity and Single Oral Dose Cure in a Murine Malaria Model  [PDF]
Patricia Ferrer, Abhai K. Tripathi, Martha A. Clark, Carla Cerami Hand, Hugh Young Rienhoff, David J. Sullivan
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0037171
Abstract: Iron chelators for the treatment of malaria have proven therapeutic activity in vitro and in vivo in both humans and mice, but their clinical use is limited by the unsuitable absorption and pharmacokinetic properties of the few available iron chelators. FBS0701, (S)3”-(HO)-desazadesferrithiocin-polyeth?er[DADFT-PE], is an oral iron chelator currently in Phase 2 human studies for the treatment of transfusional iron overload. The drug has very favorable absorption and pharmacokinetic properties allowing for once-daily use to deplete circulating free iron with human plasma concentrations in the high μM range. Here we show that FBS0701 has inhibition concentration 50% (IC50) of 6 μM for Plasmodium falciparum in contrast to the IC50 for deferiprone and deferoxamine at 15 and 30 μM respectively. In combination, FBS0701 interfered with artemisinin parasite inhibition and was additive with chloroquine or quinine parasite inhibition. FBS0701 killed early stage P. falciparum gametocytes. In the P. berghei Thompson suppression test, a single dose of 100 mg/kg reduced day three parasitemia and prolonged survival, but did not cure mice. Treatment with a single oral dose of 100 mg/kg one day after infection with 10 million lethal P. yoelii 17XL cured all the mice. Pretreatment of mice with a single oral dose of FBS0701 seven days or one day before resulted in the cure of some mice. Plasma exposures and other pharmacokinetics parameters in mice of the 100 mg/kg dose are similar to a 3 mg/kg dose in humans. In conclusion, FBS0701 demonstrates a single oral dose cure of the lethal P. yoelii model. Significantly, this effect persists after the chelator has cleared from plasma. FBS0701 was demonstrated to remove labile iron from erythrocytes as well as enter erythrocytes to chelate iron. FBS0701 may find clinically utility as monotherapy, a malarial prophylactic or, more likely, in combination with other antimalarials.
Nannochloropsis Genomes Reveal Evolution of Microalgal Oleaginous Traits  [PDF]
Dongmei Wang equal contributor,Kang Ning equal contributor,Jing Li equal contributor,Jianqiang Hu,Danxiang Han,Hui Wang,Xiaowei Zeng,Xiaoyan Jing,Qian Zhou,Xiaoquan Su,Xingzhi Chang,Anhui Wang,Wei Wang,Jing Jia,Li Wei,Yi Xin,Yinghe Qiao,Ranran Huang,Jie Chen,Bo Han,Kangsup Yoon,Russell T. Hill,Yonathan Zohar,Feng Chen,Qiang Hu,Jian Xu
PLOS Genetics , 2014, DOI: doi/10.1371/journal.pgen.1004094
Abstract: Oleaginous microalgae are promising feedstock for biofuels, yet the genetic diversity, origin and evolution of oleaginous traits remain largely unknown. Here we present a detailed phylogenomic analysis of five oleaginous Nannochloropsis species (a total of six strains) and one time-series transcriptome dataset for triacylglycerol (TAG) synthesis on one representative strain. Despite small genome sizes, high coding potential and relative paucity of mobile elements, the genomes feature small cores of ca. 2,700 protein-coding genes and a large pan-genome of >38,000 genes. The six genomes share key oleaginous traits, such as the enrichment of selected lipid biosynthesis genes and certain glycoside hydrolase genes that potentially shift carbon flux from chrysolaminaran to TAG synthesis. The eleven type II diacylglycerol acyltransferase genes (DGAT-2) in every strain, each expressed during TAG synthesis, likely originated from three ancient genomes, including the secondary endosymbiosis host and the engulfed green and red algae. Horizontal gene transfers were inferred in most lipid synthesis nodes with expanded gene doses and many glycoside hydrolase genes. Thus multiple genome pooling and horizontal genetic exchange, together with selective inheritance of lipid synthesis genes and species-specific gene loss, have led to the enormous genetic apparatus for oleaginousness and the wide genomic divergence among present-day Nannochloropsis. These findings have important implications in the screening and genetic engineering of microalgae for biofuels.
Comparative Physiology of Oleaginous Species from the Yarrowia Clade  [PDF]
Stéphanie Michely, Claude Gaillardin, Jean-Marc Nicaud, Cécile Neuvéglise
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0063356
Abstract: Yarrowia lipolytica is a genetically tractable yeast species that has become an attractive model for analyses of lipid metabolism, due to its oleaginous nature. We investigated the regulation and evolution of lipid metabolism in non-Saccharomycetaceae yeasts, by carrying out a comparative physiological analysis of eight species recently assigned to the Yarrowia clade: Candida alimentaria, Y. deformans, C. galli, C. hispaniensis, C. hollandica, C. oslonensis, C. phangngensis and Y. yakushimensis. We compared the abilities of type strains of these species to grow on 31 non hydrophobic (sugars and other carbohydrate compounds) and 13 hydrophobic (triglycerides, alkanes and free fatty acids) carbon sources. Limited phenotypic diversity was observed in terms of the range of substrates used and, in the case of short-chain fatty acids, their toxicity. We assessed the oleaginous nature of these species, by evaluating their ability to store and to synthesize lipids. The mean lipid content of cells grown on oleic acid differed considerably between species, ranging from 30% of cell dry weight in C. oslonensis to 67% in C. hispaniensis. Lipid synthesis in cells grown on glucose resulted in the accumulation of C18:1 (n-9) as the major compound in most species, except for C. alimentaria and Y. yakushimensis, which accumulated principally C18:2(n-6), and C. hispaniensis, which accumulated both C16:0 and C18:1(n-9). Thus, all species of the clade were oleaginous, but they presented specific patterns of growth, lipid synthesis and storage, and therefore constitute good models for the comparative analysis of lipid metabolism in this basal yeast clade.
Genome Characterization of the Oleaginous Fungus Mortierella alpina  [PDF]
Lei Wang, Wei Chen, Yun Feng, Yan Ren, Zhennan Gu, Haiqin Chen, Hongchao Wang, Michael J. Thomas, Baixi Zhang, Isabelle M. Berquin, Yang Li, Jiansheng Wu, Huanxin Zhang, Yuanda Song, Xiang Liu, James S. Norris, Suriguga Wang, Peng Du, Junguo Shen, Na Wang, Yanlin Yang, Wei Wang, Lu Feng, Colin Ratledge, Hao Zhang, Yong Q. Chen
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0028319
Abstract: Mortierella alpina is an oleaginous fungus which can produce lipids accounting for up to 50% of its dry weight in the form of triacylglycerols. It is used commercially for the production of arachidonic acid. Using a combination of high throughput sequencing and lipid profiling, we have assembled the M. alpina genome, mapped its lipogenesis pathway and determined its major lipid species. The 38.38 Mb M. alpina genome shows a high degree of gene duplications. Approximately 50% of its 12,796 gene models, and 60% of genes in the predicted lipogenesis pathway, belong to multigene families. Notably, M. alpina has 18 lipase genes, of which 11 contain the class 2 lipase domain and may share a similar function. M. alpina's fatty acid synthase is a single polypeptide containing all of the catalytic domains required for fatty acid synthesis from acetyl-CoA and malonyl-CoA, whereas in many fungi this enzyme is comprised of two polypeptides. Major lipids were profiled to confirm the products predicted in the lipogenesis pathway. M. alpina produces a complex mixture of glycerolipids, glycerophospholipids and sphingolipids. In contrast, only two major sterol lipids, desmosterol and 24(28)-methylene-cholesterol, were detected. Phylogenetic analysis based on genes involved in lipid metabolism suggests that oleaginous fungi may have acquired their lipogenic capacity during evolution after the divergence of Ascomycota, Basidiomycota, Chytridiomycota and Mucoromycota. Our study provides the first draft genome and comprehensive lipid profile for M. alpina, and lays the foundation for possible genetic engineering of M. alpina to produce higher levels and diverse contents of dietary lipids.
Supercritical extraction of oleaginous: parametric sensitivity analysis
Santos, M.M.;Boss, E.A.;Maciel Filho, R.;
Brazilian Journal of Chemical Engineering , 2000, DOI: 10.1590/S0104-66322000000400035
Abstract: the economy has become universal and competitive, thus the industries of vegetable oil extraction must advance in the sense of minimising production costs and, at the same time, generating products that obey more rigorous patterns of quality, including solutions that do not damage the environment. the conventional oilseed processing uses hexane as solvent. however, this solvent is toxic and highly flammable. thus the search of substitutes for hexane in oleaginous extraction process has increased in the last years. the supercritical carbon dioxide is a potential substitute for hexane, but it is necessary more detailed studies to understand the phenomena taking place in such process. thus, in this work a diffusive model for semi-continuous (batch for the solids and continuous for the solvent) isothermal and isobaric extraction process using supercritical carbon dioxide is presented and submitted to a parametric sensitivity analysis by means of a factorial design in two levels. the model parameters were disturbed and their main effects analysed, so that it is possible to propose strategies for high performance operation.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.