Browsing by Author "Arti Tiwari"

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Bioremediation potential of soil fungi in arsenic contaminated soils
(Nova Science Publishers, Inc., 2017) Vivek Kumar Singh; Chandra Bali Patel; Arti Tiwari; Punam Kumari; Ram Sanmukh Upadhyay
Microorganisms such as fungi, bacteria and algae have been reported as efficient bioremediators of heavy metals from contaminated areas. Among microorganisms, fungi execute an important role in heavy metal removal from the polluted areas. Fungi possess biochemical and ecological capacities to decrease the risk associated with metals and metalloids either by chemical modification or by influencing chemical bioavailability. Among the metal pollutants, arsenic (As) is of major concern. As has become an important soil pollutant due to the use of As-based pesticides and fertilizers, geological activities, anthropogenic impacts, disposal of municipal and industrial wastes, and irrigation with As-contaminated water. As contamination represents an ecological and health problem due to its toxic effect and invasion into the food chain. An effective As remediation through common physico-chemical techniques is expensive and unsuitable for treating large contaminated areas effectively. Bioremediation with fungi offers a promising means to reclaim such contaminated soils in economical and eco-friendly ways. Fungi are able to tolerate, biosorb and detoxify arsenicals by several mechanisms including valence transformation, extra- and intra-cellular precipitation as well as through active uptake. Soil fungi play an important role in the environmental fate of As by affecting its transformations between soluble and insoluble forms as well as toxic and non-toxic forms. Soil fungi are also able to biomethylate inorganic As species to monomethylarsonic acid (MMAA), dimethylarsinic acid (DMAA) and trimethylarsine oxide (TMAO). It has also been shown that the fungal activity can result in volatilization of As into gaseous arsines. The response of soil fungi towards toxic As is of great importance in view of their use in the remediation of As-contaminated sites. Considering the above mechanisms of resistance and removal by fungi, it could be expected that screening of As-tolerant fungi isolated from As-contaminated sites may provide an effective approach to cleaning up As-polluted soils. © 2017 by Nova Science Publishers, Inc. All rights reserved.
Fungal biomolecules and their implications
(wiley, 2015) Andleeb Zehra; Manish Kumar Dubey; Arti Tiwari; Mukesh Meena; Punam Kumari; Vivek Kumar Singh; Vijai Kumar Gupta; R.S. Upadhyay
Fungal pathogenesis requires molecular communication between the fungus and its host. Fungus-plant interactions involve complex developmental processes in which a variety of fungal and plant biomolecules are required to determine whether the outcome is a susceptible reaction (successful fungal colonisation of plant tissue) or a resistant reaction (plant mounting a defence that aborts fungal invasion). To understand the molecular basis of fungal diseases, it is necessary to identify the fungal biomolecules that are essential for pathogenic processes and to distinguish them from molecules that may be present during infection but not critical to its outcome. Some fungal biomolecules are clearly involved in the adhesion and penetration, that is, glycerol, hydrophobin, mucilage, and so on, whereas others are required for colonisation of plant tissue after penetration, that is, toxin that induce susceptibility and resistance and enzymes that inactivate plant defence mechanisms. Recent studies have shown the development of semiconductor nanoparticles, biofilms and biosensors from different fungi such as Fusarium oxysporum and Verticillium spp. © 2015 John Wiley & Sons, Ltd. All rights reserved.
Fungal toxins and their impact on living systems
(Springer India, 2014) Vivek Kumar Singh; Mukesh Meena; Andleeb Zehra; Arti Tiwari; Manish Kumar Dubey; R.S. Upadhyay
Some of the most potent toxins are synthesized by fungi. Fungal toxins are the chemicals produced by fungi under certain conditions. They may be classified under different chemical classes. They are not essential for fungal growth or reproduction, but are toxic to plants, animals or humans. Fungal toxin contamination in certain agricultural commodities has been a serious concern for animal and human health. The major toxin-producing fungi are the species of Aspergillus, Penicillium, Fusarium and Alternaria. Aflatoxins, citrinin, fumonisins, fusaric acid, moniliformin, AALtoxins and alternariol are some of the important fungal toxins responsible for causing economic losses to agriculture, spoilage of food that are often fatal to living systems. This review focuses on toxigenic fungi, toxins and their characteristics with biological effects. © Springer India 2014 This work is subject. All rights reserved.
Production and technological applications of enzymes from microbial sources
(Nova Science Publishers, Inc., 2013) Vishal Prasad; Vivek Kumar Singh; Mukesh Meena; Arti Tiwari; Andleeb Zehra; R.S. Upadhyay
Enzymes are bio-catalyst, which are produced by every living cell and which enhances the rate of chemical reactions. Enzymes are very specific in their action, highly efficient and environment friendly. Enzymes produced by plants, animals and microorganisms are exploited at industrial level for commercial use. Amongst these enzyme sources, microorganisms are preferred over plants and animals for enzyme production at the industrial level. The present chapter is aimed at providing very brief information on some aspects of microbial enzymes related to their applications in various industries, their production process and the possible tools of modern biology for the betterment of enzymes to enhance their activity and make them more beneficial for the respective industries in which they are employed. © 2013 by Nova Science Publishers, Inc. All rights reserved.