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Amit Sharma

Bio: Amit Sharma is an academic researcher from Indian Institute of Technology Roorkee. The author has contributed to research in topics: Aspergillus niger & Gluconic acid. The author has an hindex of 7, co-authored 13 publications receiving 288 citations. Previous affiliations of Amit Sharma include Indian Agricultural Research Institute.

Papers
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Journal ArticleDOI
TL;DR: Solid-state fermentation was evaluated to produce gluconic acid by metal resistant Aspergillus niger (ARNU-4) strain using tea waste as solid support and with molasses based fermentation medium and different concentrations of additives viz. oil cake, soya oil, jaggary, yeast extract, cheese whey and mustard oil were supplemented for further enhancement of the production ability of microorganisms.

91 citations

Journal ArticleDOI
TL;DR: An overall improvement of 21%, 8%, 3%, and 5% respectively in kappa number, brightness, yellowness, and viscosity of pulp was achieved under derived bleaching conditions.
Abstract: Mixed enzyme preparation having both xylanase and laccase activity was evaluated for its bleach enhancing ability of mixed wood pulp. The enzyme was produced through co-cultivation of mutant Penicillium oxalicum SAU(E)-3.510 and Pleurotus ostreatus MTCC 1804 under solid-state fermentation. Bleaching of pulp with mixed enzyme had resulted into a notable decrease in kappa number and increased brightness as compared to xylanase alone. Analysis of bleaching conditions had denoted that 8 IU g(-1) of mixed enzyme preparation (xylanase/laccase, 22:1) had led into maximal removal of lignin from pulp when bleaching was performed at 10% pulp consistency (55 degrees C, pH 9.0) for 3 h. An overall improvement of 21%, 8%, 3%, and 5% respectively in kappa number, brightness, yellowness, and viscosity of pulp was achieved under derived bleaching conditions. Process of enzymatic bleaching was further ascertained by analyzing the changes occurring in polysaccharide and lignin by HPLC and FTIR. The UV absorption spectrum of the compounds released during enzymatic treatment had denoted a characteristic peak at 280 nm, indicating the presence of lignin in released coloring matter. The changes in fiber morphology following enzymatic delignification were studied by scanning electron microscopy.

66 citations

Journal ArticleDOI
TL;DR: Improved levels of xylanase and laccase biosynthesis were achieved by co-culturing the mutant P. ostreatus MTCC 1804, which appears productive for the development of mixed enzyme preparation with tremendous potential for biobleaching.

57 citations

Journal ArticleDOI
TL;DR: An environmentally sound biobleaching to get high quality paper pulp from mixed wood pulp was attempted employing laccase from Aspergillus fumigatus VkJ2.4 as discussed by the authors.
Abstract: An environmentally sound biobleaching to get high quality paper pulp from mixed wood pulp was attempted employing laccase from Aspergillus fumigatus VkJ2.4.5 for lignin removal. Laccase treatment was performed in the presence of a mediator N-hydroxybenzotriazole (HBT, 1.5% w/w), resulting into notably higher level of delignification of the pulp. Enzyme at 10 Ug−1 of pulp at 50°C, pH 6.0, for 2 h with a pulp consistency of 10% was found suitable for enabling maximum decrease in the kappa number. The kappa number and yellowness decreased by 14 and 4% whereas ISO brightness improved by 7%. The presence of a characteristic peak at 280 nm indicated the presence of lignin in the effluent during biobleaching. Analysis of FTIR spectra of residual lignin revealed characteristic modifications following enzymatic bleaching by laccase mediator system (LMS). Variations in morphology and crystallinity of pulp were evaluated by scanning electron microscopy and X-ray diffraction analysis.

43 citations

Journal ArticleDOI
01 Mar 2011
TL;DR: Based on the proposed model, the estimated lifetime of a battery powered sensor node can be increased significantly, given the wide range of applications that can benefit from such a technology.
Abstract: Wireless sensor networks consist of small, autonomous devices with wireless networking capabilities. In order to further increase the applicability in real world applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks. In this paper, the energy consumption for wireless sensor network (WSN) node is analyzed. To estimate the lifetime of sensor node, the energy characteristics of sensor node are measured. Research in this area has been growing in the past few years given the wide range of applications that can benefit from such a technology. In this paper, analysis of energy consumption of a WSN node is analyzed with a proposed node. Based on the proposed model, the estimated lifetime of a battery powered sensor node can be increased significantly .

33 citations


Cited by
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2,133 citations

Journal ArticleDOI
TL;DR: The aim of this review is to focus on the production and extraction of bioactive phenolic compounds from natural sources by SSF, and the characteristics of SSF systems and variables that affect the product formation by this process are reviewed.

574 citations

Patent
12 Apr 2006
TL;DR: In this article, a low concentration of aqueous ammonia at high biomass concentration is used to pre-treat the pre-processed biomass and then it is further hydrolyzed with a saccharification enzyme consortium.
Abstract: Biomass is pretreated using a low concentration of aqueous ammonia at high biomass concentration. Pretreated biomass is further hydrolyzed with a saccharification enzyme consortium. Fermentable sugars released by saccharification may be utilized for the production of target chemicals by fermentation.

323 citations

Journal ArticleDOI
23 Aug 2013
TL;DR: This article overviews the enzymes produced by microorganisms, which have been extensively studied worldwide for their isolation, purification and characterization of their specific properties, and proven their utility in bio-industries such as food, leather, textiles, animal feed, and inBio-conversions and bio-remediations.
Abstract: This article overviews the enzymes produced by microorganisms, which have been extensively studied worldwide for their isolation, purification and characterization of their specific properties. Researchers have isolated specific microorganisms from extreme sources under extreme culture conditions, with the objective that such isolated microbes would possess the capability to bio-synthesize special enzymes. Various Bio-industries require enzymes possessing special characteristics for their applications in processing of substrates and raw materials. The microbial enzymes act as bio-catalysts to perform reactions in bio-processes in an economical and environmentally-friendly way as opposed to the use of chemical catalysts. The special characteristics of enzymes are exploited for their commercial interest and industrial applications, which include: thermotolerance, thermophilic nature, tolerance to a varied range of pH, stability of enzyme activity over a range of temperature and pH, and other harsh reaction conditions. Such enzymes have proven their utility in bio-industries such as food, leather, textiles, animal feed, and in bio-conversions and bio-remediations.

249 citations