Silver nanoparticles are nanoparticles of silver which are in the range of 1 and 100 nm in size. Silver nanoparticles have unique properties which help in molecular diagnostics, in therapies, as well as in devices that are used in several medical procedures. The major methods used for silver nanoparticle synthesis are the physical and chemical methods. The problem with the chemical and physical methods is that the synthesis is expensive and can also have toxic substances absorbed onto them. To overcome this, the biological method provides a feasible alternative. The major biological systems involved in this are bacteria, fungi, and plant extracts. The major applications of silver nanoparticles in the medical field include diagnostic applications and therapeutic applications. In most of the therapeutic applications, it is the antimicrobial property that is being majorly explored, though the anti-inflammatory property has its fair share of applications. Though silver nanoparticles are rampantly used in many medical procedures and devices as well as in various biological fields, they have their drawbacks due to nanotoxicity. This review provides a comprehensive view on the mechanism of action, production, applications in the medical field, and the health and environmental concerns that are allegedly caused due to these nanoparticles. The focus is on effective and efficient synthesis of silver nanoparticles while exploring their various prospective applications besides trying to understand the current scenario in the debates on the toxicity concerns these nanoparticles pose.

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Silver nanoparticles: mechanism of antimicrobial action, synthesis, medical applications, and toxicity effects

Synthesis of metallic nanoparticles using plant extracts.

Polycyclic Hydrocarbons Vol. 1. Pp. xxvi + 487. 126S. (With a chapter on carcinogenesis by Regina Schoental.) Vol. 2. Pp. lvii + 487. 140s. By E. Clar. (London and New York: Academic Press; Berlin: Springer-Verlag, 1964.)

Polycyclic Aromatic Hydrocarbons

https://www.cell.com/trends/biotechnology/pdf/S0167-7799(13)00015-2.pdf

The greener synthesis of nanoparticles

In recent years, nanobiotechnology has emerged as an elementary division of modern science and a noval epoch in the fields of material science and is receiving global attention due to its ample applications. Various physical, chemical, and biological methods have been employed to synthesize nanomaterials. Biological systems such as bacteria, fungi, actinomycetes, yeasts, viruses, and plants have been reported to synthesize various metal and metal oxide nanoparticles. Among these, biosynthesis of nanoparticles from plants seems to be a very effective method in developing a rapid, clean, nontoxic, and eco-friendly technology. The use of plant biomass or extracts for the biosynthesis of novel metal nanoparticles (silver, gold, platinum, and palladium) would be more significant if the nanoparticles are synthesized extracellularly and in a controlled manner according to their dispersity of shape and size. Owing to the rich biodiversity of plants, their potential use toward the synthesis of these nobel metal na...

Biogenic Synthesis of Metallic Nanoparticles by Plant Extracts

Laccases are blue multicopper oxidases, which catalyze the monoelectronic oxidation of a broad spectrum of substrates, for example, ortho- and para-diphenols, polyphenols, aminophenols, and aromatic or aliphatic amines, coupled with a full, four-electron reduction of O2 to H2O. Hence, they are capable of degrading lignin and are present abundantly in many white-rot fungi. Laccases decolorize and detoxify the industrial effluents and help in wastewater treatment. They act on both phenolic and nonphenolic lignin-related compounds as well as highly recalcitrant environmental pollutants, and they can be effectively used in paper and pulp industries, textile industries, xenobiotic degradation, and bioremediation and act as biosensors. Recently, laccase has been applied to nanobiotechnology, which is an increasing research field, and catalyzes electron transfer reactions without additional cofactors. Several techniques have been developed for the immobilization of biomolecule such as micropatterning, self-assembled monolayer, and layer-by-layer techniques, which immobilize laccase and preserve their enzymatic activity. In this review, we describe the fungal source of laccases and their application in environment protection.

https://downloads.hindawi.com/archive/2014/163242.pdf

Fungal Laccases and Their Applications in Bioremediation

Fungal mediated biosynthesis of silver nanoparticles, characterization and antimicrobial activity

The metallic nanoparticles have great attention of Chemists, Physists, Biologists and Engineers who wish to use them for development of new generation nanodevices. In this present study silver nanoparticles were synthesized from aqueous silver nitrate (1mM) through a simple and ecofriendly route using leaf broth of Ocimum sanctum as reductant and stabilizer. The aqueous silver ions when exposed to leaf broth were reduced and resulted in the green synthesis of silver nanoparticles ranges from 3-20 nm. The bioreduced silver nanoparticles were characterized by UVVis spectrophotometer, X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Fourier transform infra-red (FTIR) spectroscopy. The observed peaks in XRD pattern corresponding to (111), (200) and (311) planes. The FTIR measurement was carried out to identify the possible biomolecules responsible for efficient stabilization of silver nanoparticles

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Green synthesis of silver nanoparticles using ocimum leaf extract and their characterization

The production of cellulase (filter paper activity, endoglucanase and )-glucosidase) by Aspergillus niger on three media in liquid shake culture was compared. The culture filtrate of this organism exhibited relatively highest activity of all three enzymes and extracellular protein content at 7-day interval during the course of its growth on Czapek-Dox medium supplemented with 1.0% (w/v) cellulose. Urea as a nitrogen source and pH 5.0 were found to be optimal for growth and cellulase production by  A.niger . Among various soluble organic carbon sources and lignocelluloses tested in this study, carboxymethylcellulose and sawdust at 1% supported maximum production of all three enzymes by  A.niger . Keywords: Aspergillus niger , cellulase activity, nutrients, 6-glucosidase

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Nutrient effects on production of cellulolytic enzymes by Aspergillus niger

strain MS09 utilized chlorpyrifos to grow in Luria-Bertani broth containing different concentrations of chlorpyrifos at 50 -700 mg/L. However, the optimum concentration that supported bacterial growth over 24 h was found to be 50 - 200 mg/L chlorpyrifos. When compared with the control, a significant increase in bacterial growth was noted at a low concentration of chlorpyrifos (50 mg/L), whereas at higher concentrations (300 - 700 mg/L) an increased lag phase was observed, without inhibiting growth of the pesticide-utilizing bacterium. A literature survey revealed that no data is available regarding the role of

/pdf/isolation-and-characterization-of-a-chlorpyrifos-degrading-193wai2ecz.pdf

Golla Narasimha

Papers

Fungal Laccases and Their Applications in Bioremediation

Fungal mediated biosynthesis of silver nanoparticles, characterization and antimicrobial activity

Green synthesis of silver nanoparticles using ocimum leaf extract and their characterization

Nutrient effects on production of cellulolytic enzymes by Aspergillus niger

Isolation and characterization of a chlorpyrifos-degrading bacterium from agricultural soil and its growth response