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文章
M. Sunitha*, P. Ellaiah and R. Bhavani Devi
Abstract: The medium components influencing the enzyme production were screened using Plackett-Burman design. A total of 67 nutrients comprising of fifteen each of carbon, nitrogen, mineral/salt and eleven each of inorganic nitrogen sources and amino acid sources were screened for the production of L-asparaginase by SmF. This design involves screening of up to ‘n-1’ variables in just ‘n’ number of experiments. Regression coefficients and t-values were calculated by subjecting the experimental data to statistical analysis. Among the 67 nutrients based on their performance in terms of product yield and cost, tapioca starch, L-asparagine, ammonium oxalate, gelatin and CaCO3 were identified as most effective and therefore selected for inclusion in surface methodology studies.[...] Read More.
Keywords: L-asparaginase, nutritional factors, submerged fermentation, Bacillus cereus MNTG-7.
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文章
Z.  A. Zakaria*, A. S. Sufian, K. Ramasamy, N. Ahmat, M. R. Sulaiman, A. K. Arifah, A. Zuraini and M. N. Somchit 
Abstract: The aim of the present study is to determine the in vitro antimicrobial activity of various extracts, partitions and fractions of Muntingia calabura (Elaeocarpaceae) leaves against a selected panel of microorganisms. The leaves of M. calabura were soaked separately in the aqueous, chloroform and methanol solvent systems in the ratio of 1:20 (w/v) for 72 h and these procedures were repeated three times. Antimicrobial testing was carried out using the micro -broth dilution method. The microbes targeted were Staphylococcus aureus 25923, S. aureus 33591 (a multi-drugs resistant S. aureus (MRSA) isolate), Escherichia coli 35218, Pseudomonas aeruginosa ATCC 27853, Candida albicans 10231 and Microsporum canis ATCC 36299. The methanol extract inhibited MSSA (MIC = 1250 µg/ml; MBC = 1250 µg/ml) and MRSA (MIC = 1250 µg/ml; MBC = 1250 µg /ml) and considered the most effective extract and was further partitioned sequentially using the aqueous, petroleum ether and ethyl acetate. The ethyl acetate partition exhibited effective antibacterial activities with the MIC/MBC value of 156 and 313 µg/ml against S. aureus 25923 and S. aureus 33591, respectively. The ethyl acetate partition underwent fractionation process and yielded 15 fractions (A1-A15) of which only fractions A9 to A15 effectively inhibited the growth of S. aureus 25923 and S. aureus 33591 with MIC/MBC values ranging from 78 to 2500 µg/ml.[...] Read More.
Keywords: Muntingia calabura, Elaeocarpaceae, antimicrobial activity, micro-broth dilution, ethyl acetate fraction.
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文章
Omilabu A. Sunday*, A. Bankole Munir, O. Oyefolu Akeeb, A. Adesanya Bolanle and S. O. Badaru
Abstract: Studies on extracts and biologically active compounds isolated from medicinal plants have doubled in the last two decades. The leaves of Hibiscus sabdariffa (red and green leaved) and Celosia argentea were studied for their antiviral activities against Measles Virus (MV) as well as the effects of the extracts on Hep -2 cells. Ethanol extract of the leaves of each of these plants showed no toxicity to the Hep-2 cells at all concentrations used (5, 10 and 15 mg/ml). The pre-inoculative treatment of Hep-2 cells with plant extracts showed that C. argentea had no antiviral activities on MV at all concentrations (5, 10, 15 mg/ml) while H. sabdariffa had antiviral activities only at 10 and 15 mg/ml on MV. The post-inoculative treatment of Hep-2 cells with plant extracts showed that at 5, 10 and 15 mg/ml concentrations, H. sabdariffa had antiviral activities on MV while the antiviral activity of C. argentea could not be established at 10 and 15 mg/ml but did not show any antiviral activity at 5 mg/ml.[...] Read More.
Keywords: Hibiscus sabdariffa, Celosia argentea, antiviral, toxic, Hep-2 cell, herb, medicinal plant.
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Chang Gao Wang, *, Ming Kai Chen and Tao Chen
Abstract: A novel microbial phospholipase C from Bacillus mycoides strain 970 was purified to apparent homogeneity by an improved purification process, in which DEAE-Cellulose adsorption was first used to remove bulk of dark brown impurities and then a combination of DEAE-Cellulose ion-exchange, Phenyl Sepharose hydrophobic interaction and Sephacryl S-100 gel filtration chromatography was used to separate the enzyme from remained contaminants. The enzyme appeared to be a single peptide of 75.1 kDa on SDS-PAGE. The optimum temperature and pH of the enzyme were 60°C and 7.0 - 7.5, respectively. The enzyme was stable at temperatures lower than 50°C and pH 5 - 9.5. This purified phospholipase C was characterized as a metallophospholipase C and Ca2+, Mg2+ , Zn2+, Ba2+ were essential for its PLC activity. The enzyme showed no lecithinase activity on egg yolk agar and also no hemolytic activity on blood agar.[...] Read More.
Keywords: Phospholipase C, purification, metalloenzyme, nonhemolytic activity, Bacillus mycoides.
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Jing Li, Shu Zhang, Guanghua Liu, Rui Zhao, Hui Xu, Dairong Qiao and Yi Cao*
Abstract: 12 strains of lipase - producing were isolated from 36 samples collected from oil - contaminated soil of machinery - repair plant, dining room, and vegetable market, respectively, of which strain (3 - 2) had the highest hydrolytic activity (17.1 U/ml). Immobilized cell of strain 3 - 2 onto sodium alginate and immobilized crude enzyme solution of strain (3 - 2) onto Sodium alginate were respectively used in two transesterification programs to transfer the Fatty acid methyl ester (FAME). Results showed that both immobilized crude enzyme solution and cell were of high transesterification efficiency for Transesterification Program I, respectively 32.72 and 26.84%. Cycle test done in this Program found that immobilized crude enzyme solution and cell still keep some transesterification efficiency after being recycled thrice at least. Meanwhile, hydrolytic activity of crude enzyme solution had some correlation with transesterification efficiency. However, hydrolytic activity of immobilized cell did not have a clear correlation with the latter. Strain (3 - 2) belonged to Sphingobacterium multivorum. Up to now, the transesterification research has not been reported.[...] Read More.
Keywords: Lipase, crude enzyme solution, bacterial cell, immobilized, transesterification.
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文章
Özgür Güçlü*, Halil Bıyık and Aslı ahiner
Abstract: The aim of this study was to investigate the mycoflora of the loggerhead turtle, Caretta caretta, from its nests and eggshells at Fethiye Beach, Turkey. During the 2004 breeding season, following the complete emergence of the hatchlings, sand samples were collected from 15 nests and eggs from these nests were swabbed. Rose Bengal chloramphenicol agar was used for isolation, and then mycoflora were subcultured onto suitable media. Fungi were counted and identified at genus level. Ten genera were identified within the nests and eggshells. Aspergillus sp., Chrysosporium sp., Fusarium sp. and Penicillum sp. were identified both in nests and eggshells. Furthermore, while Absidia sp., Cylindrocarpon sp., Emericella sp. and Mucor sp. were only identified in the nests, Cladosporium sp. and Thielavia sp. were only identified in eggshells. In addition, there was a positive correlation between total number of isolated fungus and embryonic death in nests (r = 0.53, p < 0.05). Hatching success was negatively correlated with total number of isolated fungus (r = -0.54, p < 0.05) . Our study indicates a relation between hatching success and fungal flora of the nests. Presence of fungi may also be important for the researchers who digs nest to avoid infections or allergies due to these fungi.[...] Read More.
Keywords: Mycoflora, fungus, Caretta caretta, Fethiye beach.
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文章
Linhui Li*, Qingyu Yin, Xiaohong Liu and Hong Yang
Abstract: An  efficient  protocol  for  protoplast  isolation  and  regeneration  was  first  established  in  Coprinus Comatus. The highest yield of protoplasts was up to 8.9 × 106 cells/ml in digestion solution containing 2.0% lywallzyme and 0.6 M KCl after incubation of four-day-old mycelia at 30°C for 3 h; among which, about 1.4% protoplasts could be regenerated into mycelia after 4 - 6 days of incubation at 25°C in CYM medium with 0.6 M mannitol as osmotic stabilizer. The results are beneficial for breeding new cultivars by the methods such as protoplast fusion, mutagenesis as well as transformation. Moreover, the stepwise procedure for protoplast liberation and regeneration could be referred in other species.[...] Read More.
Keywords: Coprinus comatus, mycelia, lywallzyme, protoplast, liberation and regeneration.
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文章
A.  Torres-Morquecho, A. Rivera-Tapia, F. González-Velazquez, J. Torres, B. Chávez-Munguia, L. Cedillo-Ramírez and S. Giono-Cerezo*
Abstract: Ureaplasma sp. is associated with chronic lung disease and it has been implicated in the morbidity and mortality of new born babies (human). Adherence is an important process for lung infection, and scarce information is available in this respect. This work shows its adhesion to epithelial cells from the respiratory tract in culture, and evaluates the Ureaplasma sp. references and clinical strains isolated from premature newborns. Ureaplasma parvum and Ureaplasma urealyticum serotype 8 and five clinical samples were evaluated, using the Bertholet assay. They were observed by scanning and transmission electron microscopy to A549 cell line. Adherence was abolished by pre-treatment of ureaplasmas with A549 cell extracts and inhibited by pretreatment of ureaplasmas with N-acetylneuraminic acid, trypsine, glucose and monoclonal antibodies (mAb 106.C anti-MB against U. parvum serotype 3). Ureaplasma sp. (biotypes 1 y 2) adherence had no significant difference (P = 0.127) . The clinical strains by scanning electron microscopy showed a similar damage. Both reference and clinical strains produced evident changes in cell morphology. Micro-colonies were observed on the cells. By transmission electron microscopy, ureaplasmas attached on the cell surface and into the cytoplasm were observed. The A549 cellular line is a good model for the study of adherence of Ureaplasma sp. The urease test by Bertholet assay is a good indicator of colonization. These data suggested that ureaplasma adhesins are proteinaceous antigenic substance. Inhibition assays with neuraminidase and glucose showed binding to sialic acid residues and suggested as possible adhesin to MB (multi banded antigen).[...] Read More.
Keywords: Ureaplasma urealyticum, adherence, epithelial cells, damage.
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文章
Akaneme Florence Ifeoma* and Ene-Obong Efiom Ene-Obong
Abstract: The effects of three soil collections from old pine plantations in Nigeria: Enugu, Ugwuoba and Nsukka and a control soil on mycorrhizae development as well as morphology of the mycorrhizal rootlets, anatomical confirmation of mycorrhizae development were investigated. Enugu soil induced the greatest mycorrhizal infection (44%) and growth of seedlings. It is, therefore, recommended for nursery inoculations of pine seedlings. Bifurcate mycorrhizae characteristic of pines were observed in all treatments. Coherent rhizomorphs were found to be associated with mycorrhizae in Enugu, Ugwuoba and Nsukka soils. Anatomy of the mycorrhizae showed the presence of a fungal sheath and the cortical layer with associated Hartig net. The presence of clamp connections in the fungal sheath and rhizomorphs places the fungi involved in the class Basidiomycetes.[...] Read More.
Keywords: Mycorrhizae, Pinus caribaea, seedlings.
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文章
A. O. Ajayi* and T. A. Akintola
Abstract: Enterobacteria are often responsible for various gastrointestinal foods borne infection in humans especially in the developing countries. Cassia occidentalis, Croton zambensicus and Newbouldia leavis known as ‘Ewe ori esi’, Ajekobale and Akoko respectively in Yoruba are three plants whose leaves are used in combination by boiling to treat gastrointestinal and diarrhea illnesses among indigenes of Akungba-Akoko, Ondo State, Nigeria. The leave extracts from these medicinal plants were screened in vitro in the laboratory for their antibacterial activity against two prominent enteric bacteria, that is, Escherichia coli and Salmonella typhimurium using the agar disc diffusion method. The tyndalized leave extract of C. zambesicus showing antibacterial inhibition zone of 4 and 2 mm against S. typhimurium and E. coli respectively exhibited highest activity during the study than the autoclaved samples and other plant sources tested independently or combined, showing that the combinations of the extract samples do not exhibit synergistic effects. C. zambesicus can however be optimized clinically for chemotherapeutic control of these food-borne enteric infections.[...] Read More.
Keywords: Antimicrobial, enterobacteria, evaluation, food -borne, pathogens, plants.
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