74 research outputs found
Optimization of Xylanase Production from Penicillium citrinum in Solid-State Fermentation
Solid-state fermentation of sugarcane bagasse by Penicillium citrinum MTCC 2553 was optimized to maximize the yield of xylanase. Preliminary experiments carried out with various lignocellulosic materials revealed sugarcane bagasse to be the most suitable substrate for producing xylanase. Response surface methodology was used in the optimization. Xylanase activity was maximized in a 5-day batch fermentation carried out under the following conditions: a substrate-to-moisture ratio of 1:5 by mass, an initial pH of 7.0 and an incubation temperature of 30 °C. Under the optimal conditions, the final activity of xylanase was 1645 U gâ1 of dry substrate. Xylanase was recovered from an extract of the fermented solids by ammonium sulfate precipitation. The crude enzyme was further purified by dialysis. The activity of the enzyme was enhanced in the presence of Na+, Mg2+, Mn2+, Fe3+, Zn2+, Cu2+, Co2+ and Tween 80. The enzyme was inhibited by Hg2+, Ca2+ and the chelating agent ethylene diamine tetra acetic acid (EDTA)
Highly Crystalline and Semiconducting Imine-Based Two-Dimensional Polymers Enabled by Interfacial Synthesis
Singleâlayer and multiâlayer 2D polyimine films have been achieved through interfacial synthesis methods. However, it remains a great challenge to achieve the maximum degree of crystallinity in the 2D polyimines, which largely limits the longârange transport properties. Here we employ a surfactantâmonolayerâassisted interfacial synthesis (SMAIS) method for the successful preparation of porphyrin and triazine containing polyimineâbased 2D polymer (PIâ2DP) films with square and hexagonal lattices, respectively. The synthetic PIâ2DP films are featured with polycrystalline multilayers with tunable thickness from 6 to 200â
nm and large crystalline domains (100â150â
nm in size). Intrigued by high crystallinity and the presence of electroactive porphyrin moieties, the optoelectronic properties of PIâ2DP are investigated by timeâresolved terahertz spectroscopy. Typically, the porphyrinâbased PIâ2DP 1 film exhibits a pâtype semiconductor behavior with a band gap of 1.38â
eV and hole mobility as high as 0.01â
cm2âVâ1âsâ1, superior to the previously reported polyimine based materials
Highly Crystalline and Semiconducting Imine-Based Two-Dimensional Polymers Enabled by Interfacial Synthesis
Genomic Approaches to Enhance Stress Tolerance for Productivity Improvements in Pearl Millet
Pearl millet [Pennisetum glaucum (L.) R. Br.], the sixth most important cereal crop (after rice, wheat, maize, barley, and sorghum), is grown as a grain and stover crop by the small holder farmers in the harshest cropping environments of the arid and semiarid tropical regions of sub-Saharan Africa and South Asia. Millet is grown on ~31 million hectares globally with India in South Asia; Nigeria, Niger, Burkina Faso, and Mali in western and central Africa; and Sudan, Uganda, and Tanzania in Eastern Africa as the major producers. Pearl millet provides food and nutritional security to more than 500 million of the worldâs poorest and most nutritionally insecure people. Global pearl millet production has increased over the past 15 years, primarily due to availability of improved genetics and adoption of hybrids in India and expanding area under pearl millet production in West Africa. Pearl millet production is challenged by various biotic and abiotic stresses resulting in a significant reduction in yields. The genomics research in pearl millet lagged behind because of multiple reasons in the past. However, in the recent past, several efforts were initiated in genomic research resulting into a generation of large amounts of genomic resources and information including recently published sequence of the reference genome and re-sequencing of almost 1000 lines representing the global diversity. This chapter reviews the advances made in generating the genetic and genomics resources in pearl millet and their interventions in improving the stress tolerance to improve the productivity of this very important climate-smart nutri-cereal
Copper nanoclusters conjugated silica nanoparticles modified on carbon paste as an electrochemical sensor for the determination of dopamine
Field emission characteristics of double walled TiO2 nanotubes
Double walled TiO2 nanotubes have been synthesized by two probe anodization method on highly pure Titanium (Ti) substrate. FESEM and XRD analyses revealed the morphological and structural properties of the as-synthesized double walled TiO2 nanotubes. Investigation of their field emission characteristics in a planar diode configuration at a base pressure of 1 x 10-8 mbar has been done. The turn-on field defined for the emission current density of 10 ÂľA/cm2 is found to be 2.1 V/Âľm. As the field is increased further to 2.95 V/Âľm maximum, a current density of 890 ÂľA/cm2 is achieved. Current-time (I-t) measurement at a preset value of 1 ÂľA emission current for the duration of 3 h demonstrates a robust emission current stability. The observed low turn-on field and stable electron emission makes the double walled TiO2 nanotubes a suitable emitter for various electronics devices applications
Novel Schiff�s Base Containing Murrayanine- 1,3,4-Thiadiazole Hybrids as Potential Anti-Inflammatory Agents
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