Effect of Transgenic Rhizobacteria Overexpressing Citrobacter braakii appA on Phytate-P Availability to Mung Bean Plants

( Patel,Kuldeep J. ),( Saurabh Vig ),( G. Nareshkumar ),( G. Archana ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.11

Rhizosphere microorganisms possessing phytase activity are considered important for rendering phytate-phosphorus (P) available to plants. In the present study, the Citrobacter braakii phytase gene (appA) was overexpressed in rhizobacteria possessing plant growth promoting (PGP) traits, for increasing their potential as bioinoculants. AppA was cloned under the lac promoter in the broadhost- range expression vector pBBR1MCS-2. Transformation of the recombinant construct pCBappA resulted in high constitutive phytase activity in all of the eight rhizobacterial strains belonging to genera Pantoea, Citrobacter, Enterobacter, Pseudomonas (two strains), Rhizobium (two strains), and Ensifer that were studied. Transgenic rhizobacterial strains were found to display varying levels of phytase activity, ranging from 10-folds to 538-folds higher than the corresponding control strains. The transgenic derivative of Pseudomonas fluorescens CHA0, a well-characterized plant growth promoting rhizobacterium, showed the highest expression of phytase (~8 U/mg) activity in crude extracts. Although all transformants showed high phytase activity, rhizobacteria having the ability to secrete organic acid showed significantly higher release of P from Caphytate in buffered minimal media. AppA overexpressing rhizobacteria showed increased P content, and dry weight (shoot) or shoot/ root ratio of mung bean (Vigna radiata) plants, to different extents, when grown in semisolid agar (SSA) medium containing Na-phytate or Ca-phytate as the P sources. This is the first report of the overexpression of phytase in rhizobacterial strains and its exploitation for plant growth enhancement.

Anti-ulcer and antioxidant activity of leaves of Madhuca indica in rats

Chidrewar, G.U.,Tanavade, J.H.,Deshpande, S.H.,Vartak, P.S.,Shah, J.B.,Patel, N.P.,Patadiya, C.R.,Bafna, P.A. Kyung Hee Oriental Medicine Research Center 2010 Oriental pharmacy and experimental medicine Vol.10 No.1

The leaves of Madhuca (M.) indica J.f.Gmel. (Sapotaceae) have been used traditionally in folk medicine due to its astringent properties and are effective in treatment of eczema and snake bites. Methanolic extract of M. indica is rich in tannins and has been proven experimentally to possess antibacterial activity. The present study was undertaken to evaluate the anti-ulcer and antioxidant activity of M. indica in rats. The methanolic extract of leaves of M. indica was tested at various doses (75, 150 and 300 mg/kg, p.o.) for its effect on gastric secretion and gastric ulcers in pylorus-ligation and on ethanol- induced gastric mucosal injury in rats. The significant reduction in ulcer index in both the models along with an increase in the pH of the gastric fluid and mucin content of stomach, and the acid secretory parameters such as total acidity and volume of gastric fluid were also significantly reduced along with reduction in the pepsin activity in pylorusligated rats proved the anti-ulcer activity of M. indica. The increase in the levels of superoxide dismutase, catalase and reduced glutathione and decrease in lipid peroxidation in both the models proved the antioxidant activity of M. indica. Thus it can be concluded that M. indica possesses anti-ulcer activity, which can be attributed to its antioxidant mechanism of action.

High potential for the optimum designs for a front contact and junction: A route to heterojunction solar cell

Kim, H.S.,Yadav, P.,Patel, M.,Kim, H.,Pandey, K.,Kim, J. North-Holland ; Elsevier Science Ltd 2016 Solar energy materials and solar cells Vol.154 No.-

The present work describes a method for the development of an efficient silver nanowire (AgNWs) embedded indium tin oxide (ITO) based silicon heterojunction solar cell. The working mechanism of the heterojunction solar cell is studied by using the current-voltage (J-V) and Impedance spectroscopy (IS) techniques. The charge transfer mechanism and recombination process of the solar cell were explained by resistance, capacitance and ideality factor derived from both these techniques. A relatively high efficiency has been achieved for AgNWs embedded ITO-Si heterojunction solar cell in which AgNWs network acts as a transparent buried contact. This study also provides a new architecture for various heterojunction solar cells with a simple route of fabrication.

Enhancement of methanol production from synthetic gas mixture by Methylosinus sporium through covalent immobilization

Patel, S.K.S.,Selvaraj, C.,Mardina, P.,Jeong, J.H.,Kalia, V.C.,Kang, Y.C.,Lee, J.K. Applied Science Publishers 2016 APPLIED ENERGY Vol.171 No.-

<P>Both methane (CH4) and carbon dioxide (CO2) are major greenhouse gases (GHGs); hence, effective processes are required for their conversion into useful products. CH4 is used by a few groups of methanotrophs to produce methanol. However, to achieve economical and sustainable CH4 reduction strategies, additional strains are needed that can exploit natural CH4 feed stocks. In this study, we evaluated methanol production by Methylosinus sporium from CH4 and synthetic gas. The optimum pH, temperature, incubation period, substrate, reaction volume to headspace ratio, and phosphate buffer concentration were determined to be 6.8, 30 C, 24 h, 50% CH4, 1:5, and 100 mM (with 20 mM MgC12 [a methanol dehydrogenase inhibitor]), respectively. Optimization of the production conditions and process parameters significantly improved methanol production from 0.86 mM to 5.80 mM. Covalent immobilization of M. sporium on Chitosan significantly improved the stability and reusability for up to 6 cycles of reuse under batch culture conditions. The immobilized cells utilized a synthetic gas mixture containing CH4, CO2, and hydrogen (at a ratio of 6:3:1) more efficiently than free cells, with a maximum methanol production of 6.12 mM. This is the first report of high methanol production by M. sporium covalently immobilized on a solid support from a synthetic gas mixture. Utilization of cost-effective feedstocks derived from natural resources will be an economical and environmentally friendly way to reduce the harmful effects of GHGs. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Multi-Secondary Transformer: A Modeling Technique for Simulation - II

Patel, A.,Singh, N.P.,Gupta, L.N.,Raval, B.,Oza, K.,Thakar, A.,Parmar, D.,Dhola, H.,Dave, R.,Gupta, V.,Gajjar, S.,Patel, P.J.,Baruah, U.K. Journal of International Conference on Electrical 2014 Journal of international Conference on Electrical Vol.3 No.1

Power Transformers with more than one secondary winding are not uncommon in industrial applications. But new classes of applications where very large number of independent secondaries are used are becoming popular in controlled converters for medium and high voltage applications. Cascade H-bridge medium voltage drives and Pulse Step Modulation (PSM) based high voltage power supplies are such applications. Regulated high voltage power supplies (Fig. 1) with 35-100 kV, 5-10 MW output range with very fast dynamics (${\mu}S$ order) uses such transformers. Such power supplies are widely used in fusion research. Here series connection of isolated voltage sources with conventional switching semiconductor devices is achieved by large number of separate transformers or by single unit of multi-secondary transformer. Naturally, a transformer having numbers of secondary windings (~40) on single core is the preferred solution due to space and cost considerations. For design and simulation analysis of such a power supply, the model of a multi-secondary transformer poses special problem to any circuit analysis software as many simulation softwares provide transformer models with limited number (3-6) of secondary windings. Multi-Secondary transformer models with 3 different schemes are available. A comparison of test results from a practical Multi-secondary transformer with a simulation model using magnetic component is found to describe the behavior closer to observed test results. Earlier models assumed magnetising inductance in a linear loss less core model although in actual it is saturable core made-up of CRGO steel laminations. This article discusses a more detailed representation of flux coupled magnetic model with saturable core properties to simulate actual transformers very close to its observed parameters in test and actual usage.

Certain Subclasses of Multivalent Uniformly Starlike and Convex Functions Involving a Linear Operator

Patel, J.,Sahoo, A.K.,Cho, N.E. Eudoxus Press LLC 2015 Journal of computational analysis and applications Vol.19 No.5

Traveling Theta Waves along the Entire Septotemporal Axis of the Hippocampus

Patel, J.,Fujisawa, S.,Berenyi, A.,Royer, S.,Buzsaki, G. Cell Press 2012 Neuron Vol.75 No.3

A topographical relationship exists between the hippocampus-entorhinal cortex and the neocortex. However, it is not known how these anatomical connections are utilized during information exchange and behavior. We recorded theta oscillations along the entire extent of the septotemporal axis of the hippocampal CA1 pyramidal layer. While the frequency of theta oscillation remained same along the entire long axis, the amplitude and coherence between recording sites decreased from dorsal to ventral hippocampus (VH). Theta phase shifted monotonically with distance along the longitudinal axis, reaching ~180<SUP>o</SUP> between the septal and temporal poles. The majority of concurrently recorded units were phase-locked to the local field theta at all dorsoventral segments. The power of VH theta had only a weak correlation with locomotion velocity, and its amplitude varied largely independently from theta in the dorsal part. Thus, theta oscillations can temporally combine or segregate neocortical representations along the septotemporal axis of the hippocampus.

One-step synthesis of leaf-like, Fe₂O₃-decorated Cu structures templated by graft copolymer

Patel, R.,Jeon, H.,Kim, S.J.,Kim, J.H. North-Holland 2013 Materials letters Vol.107 No.-

Leaf-like iron oxide (Fe<SUB>2</SUB>O<SUB>3</SUB>)-decorated copper (Cu) structures were prepared by a facile, one-step templating method. An amphiphilic graft copolymer consisting of a poly(vinyl chloride) (PVC) backbone and poly(oxyethylene methacrylate) (POEM) side chains (PVC-g-POEM) synthesized via atom transfer radical polymerization (ATRP) was used as a structure-directing agent. Cu nanoparticles dispersed in the graft copolymer solution were combined with iron (III) ethoxide, followed by an in situ sol-gel reaction and calcination at 450<SUP>o</SUP>C to generate the Fe<SUB>2</SUB>O<SUB>3</SUB>/Cu structures. The morphology and elemental composition were confirmed by transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and scanning electron microscopy (SEM).

Enhancement in hydrogen production by co-cultures of Bacillus and Enterobacter

Patel, S.K.S.,Kumar, P.,Mehariya, S.,Purohit, H.J.,Lee, J.K.,Kalia, V.C. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.27

Defined co-cultures of hydrogen (H<SUB>2</SUB>) producers belonging to Citrobacter, Enterobacter, Klebsiella and Bacillus were used for enhancing the efficiency of biological H<SUB>2</SUB> production. Out of 11 co-cultures consisting of 2-4 strains, two co-cultures composed of Bacillus cereus EGU43, Enterobacter cloacae HPC123, and Klebsiella sp. HPC793 resulted in H<SUB>2</SUB> yield up to 3.0 mol mol<SUP>-1</SUP> of glucose. Up-scaling of the reactor by 16-fold resulted in a corresponding increase in H<SUB>2</SUB> production with an actual evolution of 7.44 L of H<SUB>2</SUB>. It constituted 58.2% of the total biogas. Continuous culture evolution of H<SUB>2</SUB> by co-cultures (B. cereus EGU43 and E. cloacae HPC123) immobilized on ligno-cellulosic materials resulted in 6.4-fold improvement in H<SUB>2</SUB> yield compared to free floating bacteria. This synergistic influence of B. cereus and E. cloacae can offer a better strategy for H<SUB>2</SUB> production than undefined or mixed cultures.

Bioinert membranes prepared from amphiphilic poly(vinyl chloride)-g-poly(oxyethylene methacrylate) graft copolymers

Patel, R.,Patel, M.,Ahn, S.H.,Sung, Y.K.,Lee, H.K.,Kim, J.H.,Sung, J.S. Elsevier 2013 Materials science & engineering. C, Materials for Vol.33 No.3

Poly(vinyl chloride) (PVC) membrane was hydrophilically modified by grafting with poly(oxyethylene methacrylate) (POEM) using atom transfer radical polymerization (ATRP). The successful grafting of PVC main chain by POEM was characterized by Fourier transform infrared spectroscopy (FT-IR). The molecular weight and hydrophilicity of membranes increased with the amount of POEM grafting, as characterized by gel permeation chromatography (GPC) and contact angle measurement, respectively. Transmission electron microscope (TEM) and small angle X-ray scattering (SAXS) analysis revealed the microphase-separated structure of PVC-g-POEM and the domain spacing increased from 59.3 to 86.1nm with increasing grafting degree. Scanning electron microscopy (SEM) was used for the direct visualization of the mouse embryonic fibroblast (MEF) cell and bacteria adhesion on the membrane surface. Protein adsorption and eukaryotic and prokaryotic cell adhesion tests showed that the bioinert properties of membranes were significantly increased with POEM content.