Anurag Yadav

Seasonal Population Dynamics of Rhizosphere and Non-rhizosphere Soil Microorganisms of Chir Pine Seedlings ( Pinus roxburghii Sarg.)

Seasonal population dynamics of bacteria, actinomycetes and fungi was studied in rhizosphere and non-rhizosphere soil of chir pine (Pinus roxburghii Sarg.) seedlings growing in polybags and in situ (forest). In greenhouse experiment bacteria and actinomycetes were present in higher numbers and their populations fluctuated with season. Fungal population, although lower in numbers, remained stable throughout the year. Population fluctuations with lower numbers were more prominent in rhizosphere and non-rhizosphere soils of forest plants. Differential bacterial population characteristics viz. sporeformers, fluorescent colony producers, methylene blue reducers, ammonifiers and glucose fermenters were also taken into account. The population of sporeformers was comparable with methylene blue reducers, which was higher than fluorescent colony producers, ammonifiers and glucose fermenters, respectively. The rhizosphere soil bacterial count of nursery seedlings ranged from 4.36 x 10

Nanoparticle-Based Plant Disease Management: Tools for Sustainable Agriculture

Plant diseases cause huge crop loss on a global scale and are the chief yield-limiting factor in agriculture. Due to greater utilization of land for agriculture and excessive use of fungicides and pesticides, resistant plant pathogens are spreading unprecedentedly and require an immediate check to corroborate food security. Based on need the newer crop protection technologies are emerging to ensure higher crop yield and are contributing in feeding the rapidly growing human population. Nanotechnology is one such novel technology with great potentials. From the last decade, nanotechnology as a technological science has grown to the extent that its presence can now be felt in the fields of automobiles, construction, cosmetics, electronics, and medicine. But, unlike medical nanotechnology, agriculture nanotechnology is one such technology whose potential in agriculture is yet to be fully explored. Nanotechnology deals with materials in the size range of 0.1–100 nm. Due to their minuscule size, such particles interact at an atomic or molecular level to form structures in the nanometer range. These very small particles, called nanoparticles (NPs), show properties very different from larger particles of the same element. NPs show phenomenon like Coulomb blockade, quantum nature, superparamagnetism, and surface plasmon resonance. They show surface effects due to higher surface atoms (Sharma et al Adv Colloid Interface Sci 145(1–2): 83–96, 2009) because the small size increases the surface area to volume ratio of particles (Prasad J Nanopart 2014:963961, 2014; Prasad et al. WIREs Nanomed Nanobiotechnol 8:316–330, 2016; Prasad et al Front Microbiol 8:1014, 2017a). Due to variable surface compositions, NPs have different reactivities to processor like adsorption and redox reactions (Waychunas et al. J Nanopart Res 7(4): 409-433, 2005). NPs are made from materials like carbon nanotubes, magnetic particles, metals, metal oxides, polymers (synthetic and natural), and quantum dots. They can be a designed application specific to catalyze chemical reactions.

Fungal Nanoparticles: An Emerging Tool in Medical Biology

Nanotechnology deals with production of useful materials and devices at nanoscale level. At nanoscalar dimension the particles demonstrate entirely newer properties based on “quantum effects” and physical effects like enhanced surface area. Due to the wider demand in various applications the nanoparticles synthesis require environment friendly ways without involving toxic chemicals. Fungal nanotechnology is one of the environmentally benign ways for getting nanoparticles. The filamentous nature of fungi helps in nanoparticles synthesis on the hyphal surface. As the mycelium grows the nanoparticles attach to the surface produce layers of different sizes. Fungal derived nanoparticles are applicable in various sectors of medical sciences and are the area of major research. Such nanoparticles find their application in diagnosis and treatment of several bacterial, fungal, protozoal and viral diseases. Also, they are applicable in gene bioseparation, drug delivery, magnetic resonance imaging (MRI) scans, tissue engineering, transfection and vaccine development. The research is needed to be focused on understanding the biochemical mechanism involved in the reduction of metals to metal nanoparticles, which is necessary for tapping the fungal potential for large-scale nanoparticles synthesis.