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Full Length Research Paper
Abstract: Although many studies have shown the antitumor properties of ginger extract (Zingiber officinale), little is known regarding the mechanism of its effects. This study was conducted to determine the mechanism of antitumor effects of ginger extract by evaluating apoptosis rate and cell cycle progression status in colon cancer cell lines HCT 116 and p53 defective HT 29. HCT 116 and HT 29 cells were cultured in the presence of ginger extract at various concentrations for 24 h. The percentage of cell viability was determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-di phenyl tetrazolium bromide (MTT) assay. Our results showed that ginger extract inhibited proliferation of HCT 116 and HT 29 cells with an IC50 of 496 ± 34.2 µg/ml and 455 ± 18.6 µg/ml, respectively. We also found that ginger extract at increasing concentrations induced apoptosis dose dependently in both colon cancer cells. Apoptosis rates were 11.15, 35.05 and 57.49% for HCT 116 and 4.39, 19.81 and 28.09% for HT 29 at 200, 500 and 800 µg/ml of ginger extract, respectively. Ginger extract arrested HCT 116 and HT 29 cells at G0/G1 and G2/M phases with corresponding decreased in S-phase. This study suggests that ginger extract may exert its antitumor effects on colon cancer cells by suppressing its growth, arresting the G0/G1-phase, reducing DNA synthesis and inducing apoptosis.[...] Read More.
Keywords: Zingiber officinale, HCT 116, HT 29, G0/G1 phase, S phase, apoptosis.
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文章
Juan Carlos González-Hernández
Abstract: Aquaporins are members of the major intrinsic protein superfamily of integral membrane proteins that enable the transport of water, glycerol and other solutes across membranes in diverse organisms. In yeasts, the proposed physiological roles of aquaporins are related to their contribution to freeze tolerance, osmoregulation and water transport. This article reports a contribution to the freeze tolerance in the heterologous expression of the Debaryomyces hansenii aquaporin gene in Saccharomyces cerevisiae. In the present experiments, the transformant cells were similarly sensitive to osmotic stress conditions, since their growth capacity phenotype was equivalently abolished in the presence of 0.6 and 1.0 M NaCl. Northern analysis of the yeasts studied revealed a correlation between freeze resistance and the aquaporin gene AQY1.[...] Read More.
Keywords: Debaryomyces hansenii, Saccharomyces cerevisiae, aquaporin, freeze tolerance.
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L. I. Osumah and N. J. Tonukari*
Abstract: Cassava is made up of starch as its major nutritive reserve. Starch which is one of the most important products synthesized by plants is consumed as food and can be used in industrial processes. This investigation seeks to explore the availability of cassava as a source of glucose as well as poultry manure as a source of nitrogen in the production of yeast. Cassava flour was hydrolyzed with 0.5% (v/v) concentrated H2SO4 as carbon source for the production of yeast. It was found that pH 6.5 gave optimum yeast growth. Increased concentrations of acid-hydrolyzed cassava and poultry manure extracts led to significant (P < 0.05) increase in yeast biomass after 36 h culture. The residual glucose concentration was also determined and was found to be significantly (P < 0.05) increased with increase in the concentration of poultry manure extract. Therefore, yeast can be produced using acid hydrolyzed cassava flour as carbon source with poultry manure extract as nitrogen source. The methods described in this work can be used in the development of a rapid method of producing glucose and simple sugars from cassava through acid hydrolysis and combining this with poultry manure for yeast production.[...] Read More.
Keywords: Yeast, poultry manure extract, acid-hydrolyzed cassava.
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N. Annamalai*, S. Giji, M. Arumugam and T. Balasubramanian
Abstract: Chitinase producing bacterial strain Micrococcus sp. AG84 isolated from marine sediments grew maximally in shake flask and produced chitinase at 35°C, pH 8.0. Chitinase activity was found to be maximum at 45°C, pH 8.0, and the enzyme was 100% stable even at 60°C and pH 11.0. Added with Fe2+, Ca2+ and Ni2+ chitinase activity increased but it was inhibited by EDTA. The molecular weight of purified chitinase is 33 kDa.[...] Read More.
Keywords: Micrococcus sp. AG84, chitinase, thermostable, alkaline, marine.
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Mahmoud Z. Sitohy, Mona M. Rashad*, Samy F. Sharobeem, Abeer E. Mahmoud, Mohamed U. Nooman and Amr S. Al Kashef
Abstract: The production and properties of biosurfactants synthesized by Candida guilliermondii NRRL Y-2075 and Bacillus subtilis NRRL B- 94 using soy processing waste (okara) as substrate were investigated under different fermentation techniques. Higher oil displacement activities for the isolated biosurfactants were achieved by using submerged fermentation technique (SMF) for both organisms. Preliminary chemical characterization and IR spectroscopy for C. guilliermondii biosurfactant revealed that, it is mainly a glycolipid complex, while that of B. subtilis biosurfactant was found to be a complex mixture of lipoprotein and glycolipid. Both biosurfactants formed stable water-in-oil emulsions with motor oil and sunflower oil, while soybean oil was only emulsified by C. guilliermondii biosurfactant. The surface tension of water was reduced to 51 mN/m by C. guilliermondii biosurfactant at a critical micelle dilution (CMD) of 8% concentration, while B. subtilis biosurfactant showed a minimum surface tension of 48 mN/m at CMD value of 10% concentration. Both biosurfactants exhibited good antimicrobial activity against the tested bacteria and yeast strains with different values of minimum inhibitory concentrations (MIC).[...] Read More.
Keywords: Surfactant, Candida guilliermondii, Bacillus subtilis, soy processing waste, submerged fermentation.
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Barnali Sarma, Celin Acharya and S. R. Joshi*
Abstract: Pseudomonads is a versatile and cosmopolitan bacterial group that can occur in metal contaminated as well as clinical environment and many of them possess the ability to proliferate resistance to bacteria from their own or other group. Antibiotic resistance in clinical bacteria is a growing concern for mankind. Various reports have shown dual resistance of pseudomonads to metal and antibiotic involving different inheritable or non-inheritable mechanisms like co-resistance, cross-resistance, co-regulation, biofilm production, persistence and swarming. Increasing rate of metal pollutant in environment contributed by various anthropogenic activities may constantly provide a selective pressure in proliferation of antibiotic resistance among bacteria.[...] Read More.
Keywords: Pseudomonads, dual-resistance, metals, antibiotics, inheritable, non-inheritable.
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文章
Daniel Palmero*, Miguel De Cara, Marta María Moreno, Concepción Iglesias and Julio Cesar Tello
Abstract: The mycelial growth of eleven Fusarium oxysporum strains, eight isolated from seabed soil of the South- eastern Mediterranean coast of Spain and three formae speciales from diseased plants were tested on potato-dextrose-agar adjusted to different osmotic pressures with either KCl or NaCl (-1.50 to -144.54 bar) at 10°C intervals ranging from 15 to 35°C. The extent of growth of F. oxysporum shows the same pattern for isolates from the seabeds that for isolates of Formae speciales. Maximal growth was observed at -13.79 bar of osmotic pressure at 25°C with an acute decrease at -41.79 bar and lower. At 35°C maximal growth was observed at -41.79 bar of osmotic pressure not only for seabeds isolates but also for pathogenic F. speciales isolates. These findings could indicate that F. oxysporum is well adapted to exist in moderate saline habitats. It does not seem that the pathogenicity of the isolates is a factor that determines the response to the salinity, but that behavior seems to be common to all the isolates studied and it could be speculated to be a specific behavior.[...] Read More.
Keywords: Salinity, soilborne pathogens, conductivity, osmotic pressure.
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文章
Mohammad Asgharzadeh*, Hossein Samadi Kafil, Kazem Najati and Khalil Ansarin
Abstract: Mycobacterium tuberculosis is responsible for considerable human morbidity and mortality worldwide. Based on the presence or absence of M. tuberculosis specific deletion (TbD1), M. tuberculosis isolates are divided into ancestral and modern strains. The aim of this study was to differentiate ancestral and modern M. tuberculosis in northwest of Iran. 165 M. tuberculosis strains were isolated from West and East Azarbaijan provinces of Iran. Ancient and modern M. tuberculosis isolates were distinguished by primer specific polymerase chain reaction (PCR). This study showed that 49 (29.7%) of the isolates were modern M. tuberculosis and 116 (70.3%) were ancestral M. tuberculosis. The prevalence of modern M. tuberculosis in West Azarbaijan was relatively higher than that of East Azarbaijan. Considering the increasing rate of modern M. tuberculosis in the studied region and in world, which has resulted in multi-drug resistance and low preventive effect of bacillus of calmette and guerin (BCG) vaccine, the fast diagnosis, prevention, treatment and more controlling programs of the infection, is important in this region.[...] Read More.
Keywords: TbD1, modern tuberculosis, ancestral tuberculosis, PCR.
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Thanawan Kantha, Chaiyavat Chaiyasut*, Duangporn Kantachote, Suchada Sukrong and Amorntip Muangprom
Abstract: Soil samples from organic saline paddy fields from 14 provinces of the northeast region of Thailand were collected and used for isolating photosynthetic bacteria (PB) prepared as a Soil and Straw Products (SSPs). PB from these SSPs were further grown in double strength G5 broth under microaerobic-light conditions before purification. A total of 130 isolates were then screened for growth in G5 broth under microaerobic-dark conditions for 24 h and 15 isolates were further selected by secondary screening in G5 broth under microaerobic-light conditions for 24 h. Four isolates (tk35, tk85, tk103 and tk123) were selected and all were identified as Rhodopseudomonas palustris based on their 16S rRNA gene. After incubation in SSP for 4 weeks with microaerobic-dark conditions, all SSPs had pH values in a range of 5.33 -7.17 and electrical conductivity (EC) values were between 3.02-12.93 dS/m. It was also found that the 5-aminolevulinic acid (ALA) content increased with time to achieve levels of 2.95, 2.94, 2.95 and 2.96 mM, from strains tk35, tk85, tk103 and tk123, respectively. The results indicate that SSP containing selected PB could produce ALA and this could be practically applied to organic saline paddy fields and increase growth and yields of rice.[...] Read More.
Keywords: Photosynthetic bacteria (PB), soil and straw product (SSP), 5-aminolevulinic acid (ALA), organic saline paddy field.
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文章
Xiu Xiang Tao,*, Hui Chen, Kai Yi Shi and Zuo Peng Lv
Abstract: Fungus, named TZ1, was isolated from coal mine soil at the Fushunxi colliery, Liaoning Province, North of China. The lignite’s bioconversion rate was about 23.3% by TZ1. The morphological, biochemical, physiological characterization and analysis based on 18S rDNA gene sequence indicated that the strain TZ1 was most closely related to Hypocrea lixii (100% similarity in gene sequence), bioconversion lignite experiments with this new strain showed that it could play an important role in degradation of Chinese lignite.[...] Read More.
Keywords: Lignite, bio-conversion, Hypocrea lixii.
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