184 research outputs found
A bioprocess optimization study to enhance the production of Menaquinone-7 using Bacillus subtilis MM26
No full textAbstract Background Menaquinone-7 (MK-7) has a vital significance in promoting human health and tackling several global health concerns which makes its production extremely important. MK-7 is not easily accessible at a reasonable cost due to the poor fermentation yields and the existence of several laborious downstream unit processes. Efficient manufacturing methods are essential to meet the global requirements due to the increasing demand in the pharmaceutical and nutraceutical industries. This research study focuses on the enhanced production of MK-7 from Bacillus subtilis MM26 isolated from fermented home-made wine. Results A suitable MK-7 production medium for Bacillus subtilis MM26 was determined and the yield was found to be 67 ± 0.6 mg/L. The one factor at a time (OFAT) results showed that medium containing lactose, glycine, with a pH 7, a temperature of 37 °C, and an inoculum size of 2.5% (2 × 10⁶ CFU/mL) was optimal synthesis of MK-7. RSM indicated that incubation time, carbon and nitrogen sources were the factors significantly affecting the MK-7 yield. RSM predicted optimal conditions, which yielded a maximum concentration of 442 ± 2.08 mg/L of MK-7. Conclusions The outcomes of this study demonstrated the potential of Bacillus subtilis MM26 in large-scale industrial production of MK-7. The yield of MK-7 was amplified efficiently by integration of OFAT and RSM, paving the way for cost-efficient industrial production
Sitā et ses doubles (mythes et représentations dans les oeuvres d'Ananda Devi)
No full textNotre recherche vise à cerner la quête identitaire de la femme dans les romans d Ananda Devi, auteur mauricien, d origine indienne. D après nos analyses, nous constatons que l individuation féminine se déploie à travers les trois phases suivantes : l identité-idem , l aspect identitaire qui se fonde sur une identification collective ; l identité-ipsé , par opposition à cette quête de similitude, est un élan vers la spécificité personnelle ; et l animus que nous définissons comme la part de différence ou les désirs les plus refoulés qui sont rejetés par les normes sociales. Parallèlement à ces trois phases identitaires, ce qui caractérise l'évolution féminine chez Devi, c est que la femme opprimée, dans son effort d émancipation, s inspire des figures mythiques hindoues. Au cours de notre recherche nous avons exploité les bribes mythiques, afin de mettre en lumière une communion prédominante entre les femmes de Devi et les figures mythiques hindoues : Sitā, Draupadi et Kālī. Or, cette expérience d identification avec les figures mythiques recoupe les trois phases identitaires dans la mesure où la femme s identifie à une figure mythique dans chacune de ces phases d individuations. L accouplement figure mythique et phase identitaire se présente ainsi : Sitā-identité-idem, Draupadi-identité-ipsé, et Kālī-animus.The aim of this research is to study the quest of identity in the women characters in Ananda Devi s novels. Devi is a Mauritian author of Indian origin. Our study reveals that the evolution of the women passes through three major stages : l identité-idem or collective identification, the desire of identifying oneself to a particular group; l identité-ipsé on the contrary is the desire to see oneself as unique within a certain group of individuals; l animus , we define this term as the suppressed desires which are condemned by the society. Along with these three phases of identification, what characterises Devi s women is that in their serge for emancipation they identify themselves with the Hindu mythical figures. In our study we have explored various images in Devi s writings in order to reveal the existing links between Devi s women and the following mythical figures : Sitā, Draupadi, Kālī. In fact, this experience of identification with the mythical figures is closed interlinked with the evolutionary phases defined above. In each of her evolutionary phase the woman identifies to one particular mythical figure : Sitā-identité-idem, Draupadi-identité-ipsé, and Kālī-animus.PARIS13-BU Droit-Lettres (930792101) / SudocSudocFranceF
PRESSURE BROADENING OF LINES IN THE REGION
No full text M. A. H. Smith, C. P. Rinsland, V. Malathy Devi, J.-M. Flaud, C. Camy-Peyret, and A. Barbe, J. Mol. Spectrosc., 139, 171-181 (1990). C. Camy-Peyret, J.-M. Flaud, M. A. H. Smith, C. P. Rinsland, V. Malathy Devi, J. J. Plateaux, and A. Barbe, J. Mol. Spectrosc., in press (1990).Author Institution: Atmospheric Sciences Division, Mall stop 401A, NASA Langley Research Center; Physics Department, College of William and Mary; Atmospheric Sciences Division, Mail stop 401A, NASA Langley Research CenterWe have recorded a series of high-resolution absorption spectra of ozone broadened by dry air, by , and by at room temperature using the McMath Fourier transform spectrometer at the National Solar Observatory on Kitt Peak. The spectra cover a wavenumber range from approximately to at a resolution of . Using recently-determined line positions, assignments, and , we have analyzed these spectra to determine pressure broadening and line shift coefficients for a number of lines in the and , band systems
SELF-AND -BROADENING AND SHIFT COEFFICIENTS IN THE BAND OF : REVISITED
No full textD. Chris Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith and D. Atkins, JQSRT 53, 705-721 (1995). V. Malathy Devi, D. Chris Benner, M. A. H. Smith, C. P. Rinsland and A. W. Mantz, JQSRT 75, 455-471 (2002).Author Institution: Department of Physics, The College of William and Mary; Department of Physics, The University of Lethbridge; Atmospheric Sciences, NASA Lang-ley Research Center; Department of Physics, Astronomy and Geophysics, Connecticut CollegeRoom temperature values for self-broadened and hydrogen-broadened Lorentz half width coefficients, and self and hydrogen pressure-induced shift coefficients have been measured for transitions with rotational quantum number index m ranging from -24 to +24 in the band of . The spectra were recorded with the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory on Kitt Peak. The analysis was performed using a multispectrum nonlinear least squares modified to constrain the Lorentz widths in the P and R branches to be identical for the same value. We have compared the present results with our previous measurements made with the same and with other measurements published recently
BROADENING AND SHIFT COEFFICIENTS IN THE BAND OF HCN
No full textD. Chris Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith and D. Atkins, JQSRT 53, 705-721 (1995). V. Malathy Devi et al., JQSRT, in press (2004). V. Malathy Devi et al., JQSRT 82, 319-341 (2003); C. P. Rinsland et al., JQSRT 82, 343-362 (2003).Author Institution: Atmospheric Sciences, NASA Langley Research Center; Department of Physics, The College of William and Mary; Department of Physics, Pacific Northwest National LaboratoryInfrared spectra of HCN in the region were recorded at 0.008 and resolution using two different Fourier transform spectrometers (FTS), the McMath-Pierce FTS at the National Solar Observatory on Kitt Peak and the Bruker IFS 120 HR FTS at the Pacific Northwest National Laboratory. Spectra were recorded with pure HCN as well as mixtures of HCN in air at temperatures between and . Using our multispectrum technique, we fit over 30 spectra simultaneously to determine self-broadening and shift coefficients and air-broadening and shift coefficients and their temperature dependences for lines belonging to the band centered near . In addition, we were able to determine broadening and shift parameters for some lines belonging to hot bands and isotopic bands. The results will be compared with our previous measurements in the and in the and with other measurements available in the literature
Potential application of immobilized streptokinase extracted from <i>Streptococcus equinus</i> VIT_VB2
No full textAcid stable α-amylase from Pseudomonas balearica VITPS19—Production, purification and characterization
No full textIn the present study, α-amylase from Pseudomonas balearica VITPS19 isolated from Kolathur, Tamil Nadu, India was studied. Initially, one factor at a time (OFAT) approach was used to optimize the medium parameters like pH, temperature, carbon and nitrogen sources and the presence of metal ions to enhance the amylase activity. After the optimization, 6.5-fold increase in the enzyme production was observed. Enzyme purification was carried out in three stages. The molecular weight of purified α-amylase was estimated to be 47 kDa.The optimum activity for the purified enzyme was observed at pH 6 in 0.1 M phosphate buffer at 25 ± 2 °C and the activity is enhanced in the presence of ions like Mn2+, Mo6+, Na+, Mg2+and Zn2+ and was inhibited in the presence of Hg2+ ions. Compounds such as Sodium dodecyl sulfate (SDS), Ethylenediaminetetraacetic acid (EDTA), urea and β- mercaptoethanol reduced the amylase activity. The Km and Vmax of the α-amylase was estimated to be 45.23 mM and 20.83 U/mL, respectively
BROADENING AND SHIFT COEFFICIENTS IN THE AND LASER BANDS
No full textV. Malathy Devi, D. Chris Benner, M. A. H. Smith and C. P. Rinsland, JQSRT 59, 137-149 (1998). D. Chris Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith and D. Atkins, JQSRT 53, 705-721 (1995). L. S. Rothman et al., JQSRT 60, 665-710 (1998).Author Institution: The College of William and Mary; Department of Physics, The College of William and Mary; Department of Physics, NASA Langley Research Center; Atmospheric Sciences, NASA Langley Research Center; Atmospheric Sciences, California Institute of Technology; Jet Propulsion Laboratory, National Solar ObservatoryIn a previous we had reported air- and -broadening and pressure-induced shift coefficients for 46 rovibrational transitions in the and laser bands near These parameters were determined from spectra recorded with the McMath-Pierce Fourier transform spectrometer (FTS) of the National Solar Observatory on Kitt Peak, Arizona. We now report similar measurements of air- and -broadening and shifts for the two laser bands, plus new determinations of self-broadening and shifts in the laser bands. These results were obtained from simultaneous analysis of 30 long-path absorption spectra using a multispectrum . In addition to the 10 spectra of air-and -broadened natural analyzed previously, we have included 20 new spectra recorded at room temperature and resolution using the McMath-Pierce FTS. These additional spectra include two low pressure, four air-broadened and four -broadened spectra obtained with a -enriched sample and 10 self-broadened spectra obtained with a high purity natural sample. The self-broadened spectra were recorded with pathlengths of 73, 97, 193 and 433 m and pressures varying between 3 Torr and 400 Torr. The spectra were obtained with a pathlength of 84 m with sample pressures < 4 Torr for the low-pressure spectra and from 100 to 500 Torr for the air- and -broadened mixtures. By combining the spectra of and in the same fit we were able to obtain a consistent set of line parameters for both molecules. The results obtained for the and laser bands will be compared with each other, with the values in the HITRAN , and with available values reported in the literature
Bio prospecting of Riboflavin producing bacteria from different riboflavin enriched food sources
No full textRiboflavin is an essential, water-soluble vitamin (B2) and a component of basic cellular metabolism. The aim of the present study is to isolate and characterize riboflavin producing bacteria from different food sources. Ten different riboflavin enriched food sources were collected from Vellore district. Totally 72 bacterial strains were isolated and cultured on nutrient agar plates. Out of these, 43 strains were identified as riboflavin producers. Isolated bacterial strains HDS27, HDS07, HDS14, HDS18, HDS38 and HDS54 isolated from milk, mushroom, spinach, lamb kidney, beef liver and mackerel fish were found to be potent riboflavin producers. Based on morphological, biochemical and molecular characterization, the potent strains were identified as Lactobacillus plantarum (HDS27), Bacillus cereus (HDS07), Delftia tsuruhatensis (HDS14), Citrobacter freundii (HDS18), Enterobacter cloacae (HDS38) and Bacillus cereus (HDS54). The selected potent isolates HDS27 from milk and HDS07 from mushroom showed a maximum riboflavin production of 3.69 mg/L and 2.9mg/L respectively. The present study explores the riboflavin producing novel bacteria from different food sources. This is the first report that the Enterobacter cloacae isolated from beef liver, Delftia tsuruhatensis from spinach and Citrobacter freundii from lamb kidney has the ability to produce riboflavin. These potent strains could be a better starter for substituting the conventional bacteria for large scale production of riboflavin in industry
Biosynthesis and therapeutic applications of MK-7: A comprehensive review
No full textThe fat-soluble vitamin K is an indispensable cofactor that transmutes the glutamic acid residues to -γ-carboxyglutamic residues in blood and bones. Vitamin K is further classified into three namely, Phylloquinone, Menaquinone and Menadione. Both, phylloquinone and menaquinone are naturally derived types of vitamin K while Menadione is a synthetic variant. Among the several types of vitamin K, Menaquinone-7 (MK-7) stands out because of its extended half-life. MK-7 is found to have potential therapeutic effects in preventing cardiovascular disease, osteoporosis, diabetes, Alzheimer and cancer. Comprehending the diverse functions of MK-7 provides valuable perspectives on its ability to enhance overall health. During microbial fermentation, certain strains are selected and improved for effective synthesis of MK-7. Researchers are investigating industrial-scale production techniques such as fermentation conditions, downstream processing, and purification methods to increase both quantity and quality. This review highlights MK-7’s diverse biological functions and industrial significance, emphasizing advancements in microbial fermentation, including strain improvement and production optimization, to enhance yield and quality
- …
