Papers by Utkarsha Shedbalkar
Next sustainability, 2024
Annals of Microbiology, Nov 27, 2010
The intracellular bacterial peroxidase from Pseudomonas sp. SUK1 was purified by anion exchange a... more The intracellular bacterial peroxidase from Pseudomonas sp. SUK1 was purified by anion exchange and molecular sieve chromatography. The molecular weight of the purified peroxidase was estimated to be 86 kDa by SDS-PAGE analysis. The UV-visible absorption spectra revealed that the purified peroxidase was a heme-containing protein. The purified enzyme exerted its optimal activity with n-propanol and also oxidized various lignin-related phenols, whereas no activity was observed with p-cresol and veratrole. Optimum pH and temperature for the purified peroxidase were 3.0 and 40°C, respectively. The purified enzyme proficiently decolorized various textile dyes. Methyl orange was used as a model azo dye to understand the mechanism of action of peroxidase in dye degradation. Further, dye degradation was confirmed by analytical techniques like FTIR, HPLC and GC-MS.
AMB Express, Dec 1, 2017
Metals present in environment render the bacteria to attain certain resistance machinery to survi... more Metals present in environment render the bacteria to attain certain resistance machinery to survive, one of which is transformation of metal ions to nano forms. Various enzymes and proteins have been suggested to play significant role in synthesis of silver nanoparticles (AgNPs) in bacteria. In present study, we have purified lignin peroxidase from secreted enzyme extract of Acinetobacter sp. employing diethyl aminoethyl cellulose ion exchange and Biogel P-150 gel filtration column chromatography. The purified fraction has a specific activity of 1.571 U/mg with substrate n-propanol and 6.5-fold purification. The tetrameric enzyme, with molecular weight of 99 kDa, consisted of dimers of two polypetides of 23.9 and 24.6 kDa as revealed by native and SDS-PAGE. On exposure to purified enzyme, spherical polydispersed AgNPs of ~ 50 nm were obtained as observed under transmission electron microscope. Optimum activity of the purified enzyme was obtained at pH 2 and 60 °C with n-propanol as substrate. This is the first report describing the reduction of extracellular silver ions by lignin peroxidase purified from Acinetobacter sp.
Applied Microbiology and Biotechnology, May 9, 2015
Journal of Hazardous Materials, Sep 1, 2008
Triphenylmethane dyes belong to the most important group of synthetic colorants and are used exte... more Triphenylmethane dyes belong to the most important group of synthetic colorants and are used extensively in the textile industries for dying cotton, wool, silk, nylon, etc. They are generally considered as the xenobiotic compounds, which are very recalcitrant to biodegradation. Penicillium ochrochloron decolorizes cotton blue (50 mg l(-1)) within 2.5 h under static condition at pH 6.5 and temperature 25 degrees C. TLC, FTIR and HPLC analysis confirms biodegradation of cotton blue. FTIR spectroscopy and GC-MS analysis indicated sulphonamide and triphenylmethane as the final products of cotton blue degradation. The pH, temperature and maturity of biomass affected the rate of decolorization. Presence of lignin peroxidase, tyrosinase and aminopyrine N-demethylase activities in the cell homogenate as well as increase in the extracellular activity of lignin peroxidase suggests the role of these enzymes in the decolorization process. The phytotoxicity and microbial toxicity studies of extracted metabolites suggest the less toxic nature of them.
Apple Academic Press eBooks, Jan 19, 2023
Elsevier eBooks, 2020
Abstract The science of nanotechnology is gaining pace rapidly in various sectors such as medical... more Abstract The science of nanotechnology is gaining pace rapidly in various sectors such as medical, pharmaceutical, agricultural, industrial, environmental, etc. Its estimated that global and United States markets are comprised of more than 1000 nano-enabled consumer products worth trillions of dollars. Given the rapid growth of nano-based products, there is a higher risk of exposure to toxic nanomaterials through various pathways such as inhalation, ingestion, skin penetration, etc. This has negative impacts on human health that cause pulmonary cytotoxicity, dermal toxicity, DNA damage, etc. Members of aquatic/marine and terrestrial ecosystems such as plants, animals, bacteria, fungi, and algae have also been reported to be affected due to bioaccumulation, biomagnifications phenomenon exhibited by different types of man-made nanomaterials. This chapter will shed light on one of such type of engineered nanomaterial: carbon nanomaterials (CNMs). Their structures, properties, and types will be discussed along with their beneficial industrial applications. Major emphasis is given on the econanotoxicological impacts of CNMs; their life cycle, transport, and fate when released unintentionally into an environment; and their subsequent behavior in ecosystems, along with a few case studies. To sustainably adopt the emerging science of nanotechnology, gaps in the current knowledge as well as challenges and recommendations to overcome them are also discussed.
Journal of Nanoscience and Nanotechnology, Jun 1, 2018
Acinetobacter baumannii has emerged as one of the major nosocomial pathogens implicated in variet... more Acinetobacter baumannii has emerged as one of the major nosocomial pathogens implicated in variety of severe infections and mortality. It is rapidly developing multi-drug resistance and also possesses surface colonization ability, which make it most difficult to treat through traditional antibiotics. This is an extensive study to describe the antibacterial activity of bacteriagenic silver nanoparticles (AgNPs) against A. baumannii AIIMS 7 in planktonic and biofilm mode. Minimum inhibitory concentration of antibiotics were in the range of 1 to 4096 g/ml whereas AgNPs inhibited planktonic bacteria at concentration of 16 g/ml. Fractional inhibitory concentration index revealed the synergistic interaction of AgNPs with doxycycline, tetracycline and erythromycin. Nanoparticles exhibited significant biofilm disruption activity with minimum biofilm eradication concentration of 2 mg/ml. Eradication of mature biofilm was enhanced on exposure to combination of AgNPs and antibiotics. These nanoparticles affected bacterial growth and distorted cellular morphology. Intracellular oxidative stress, induced in presence of AgNPs, also rendered bacteria susceptible to killing by nanoparticles. Besides this, AgNPs were found to interact with thiol-groups, which indicate their potential to interact with cellular proteins to exhibit antimicrobial activity.
Enzyme and microbial technology, Apr 1, 2018
Synthesis of nanoparticles is an enzymatic reduction process in microorganisms. In the present st... more Synthesis of nanoparticles is an enzymatic reduction process in microorganisms. In the present study, a protein, lignin peroxidase has been purified by DEAE-Cellulose anion exchange chromatography and Biogel P-150 gel filtration chromatography from the cell suspension of Acinetobacter sp. SW30 responsible for the synthesis of gold nanoparticles (AuNP) and selenium nanoparticles (SeNP). The purified fraction has a specific activity of 29.4 U/mg/min with 959 fold purification. Native and SDS PAGE confirmed that purified lignin peroxidase is monomeric enzyme with 97.4 KDa molecular weight. The enzyme synthesized spherical crystalline AuNP (10 ± 2 nm) and amorphous SeNP (100 ± 10 nm). It has maximum activity at pH 2 and temperature 40°C, with 1.0 mM Km value, when n-propanol was used as a substrate. Activity was completely inhibited by sodium thiosulphate and zinc sulphate. This is the first report on association of lignin peroxidase in the synthesis of AuNP and SeNP from Acinetobacter sp. SW30.
Environmental Technology and Innovation, Apr 1, 2016
h i g h l i g h t s • Current status of nanotechnology for environmental clean-up. • Ecological a... more h i g h l i g h t s • Current status of nanotechnology for environmental clean-up. • Ecological and human health risks associated with the use of nanomaterials. • Sustainable, advanced engineered and regulatory measures for existing problems.
Applied Microbiology and Biotechnology, Jan 22, 2016
Selenium nanoparticles (SeNPs) are gaining importance in the field of medicine owing to their ant... more Selenium nanoparticles (SeNPs) are gaining importance in the field of medicine owing to their antibacterial and anticancer properties. SeNPs are biocompatible and non-toxic compared to the counterparts, selenite (SeO3 (-2)) and selenate (SeO4 (-2)). They can be synthesized by physical, chemical, and biological methods and have distinct bright orange-red color. Biogenic SeNPs are stable and do not aggregate owing to natural coating of the biomolecules. Various hypotheses have been proposed to describe the mechanism of microbial synthesis of SeNPs. It is primarily a two-step reduction process from SeO4 (-2) to SeO3 (-2) to insoluble elemental selenium (Se(0)) catalyzed by selenate and selenite reductases. Phenazine-1-carboxylic acid and glutathione are involved in selenite reduction. Se factor A (SefA) and metalloid reductase Rar A present on the surface of SeNPs confer stability to the nanoparticles. SeNPs act as potent chemopreventive and chemotherapeutic agents. Conjugation with antibiotics enhances their anticancer efficacy. These also have applications in nanobiosensors and environmental remediation.
Tropical Plant Biology, Aug 24, 2010
Biotechnology and Bioprocess Engineering, Feb 1, 2008
Indian Journal of Microbiology, May 27, 2016
Cell biomass and metal salt concentration have great influence on morphology of biosynthesized na... more Cell biomass and metal salt concentration have great influence on morphology of biosynthesized nanoparticle. The aim of present study was to evaluate the effect of varying cell density and gold salt concentrations on synthesis of nanoparticles and its morphology, which has not been studied in bacteria till now. When cells of Acinetobacter sp. SW30 were incubated with different cell density and gold chloride concentrations, tremendous variation in color of colloidal solution containing gold nanoparticles (AuNP) was observed indicating variation in their size and shapes. Surprisingly, monodispersed spherical AuNP of size *19 nm were observed at lowest cell density and HAuCl 4 salt concentration while increase in cell number resulted in formation of polyhedral AuNP (*39 nm). Significance of this study lays in the fact that the shape and dispersity of AuNP can be customized depending up on the requirement. FTIR spectrum revealed shift from 3221 to 3196 cm-1 indicating the presence and role of amino acids in Au 3? reduction while possible involvement of amide I and II groups in stabilization of AuNP. The rate constant was calculated for cell suspension of 2.1 9 10 9 cfu/ml challenged with 1.0 mM HAuCl 4 , incubated at 30°C and pH 7 using the slopes of initial part of the plot log (A a-A t) versus time as 1.99 9 10-8 M. Also, this is the first study to report the kinetics of gold nanoparticle synthesis by Acinetobacter sp. SW30.
World Journal of Microbiology & Biotechnology, Jul 1, 2014
Journal of Industrial Microbiology & Biotechnology, Jul 26, 2008
Morphologically different, three bacterial strains, capable of decolorizing Reactive Blue 59 were... more Morphologically different, three bacterial strains, capable of decolorizing Reactive Blue 59 were isolated from dye effluent contaminated soil sample, collected from Ichalkaranji, India. The individual bacterial strains viz. Bacillus odysseyi SUK3, Morganella morganii SUK5 and Proteus sp. SUK7 decolorized Reactive Blue 59 (50 mg l-1) completely within 60, 30, 24 h, respectively, while the bacterial consortium PMB11 of these strains required 3 h for the complete decolorization. The decolorization was confirmed by UV-Vis spectroscopy. Further, the biodegradation of Reactive Blue 59 in to different metabolites was confirmed by High performance liquid chromatography and Fourier transform infrared spectroscopy analysis. Significant increase in the activity of aminopyrine N-demethylase (AND) in the individual as well consortium cells, obtained after decolorization showed involvement of AND in the decolorization process. Phytotoxicity studies, revealed the nontoxic nature of the degraded metabolites of Reactive Blue 59 indicating effectiveness of bacterial consortium PMB11 for the treatment of textile effluent containing Reactive Blue 59.
Advances in Colloid and Interface Science, Jul 1, 2014
Gold nanoparticles have been employed in biomedicine since the last decade because of their uniqu... more Gold nanoparticles have been employed in biomedicine since the last decade because of their unique optical, electrical and photothermal properties. Present review discusses the microbial synthesis, properties and biomedical applications of gold nanoparticles. Different microbial synthesis strategies used so far for obtaining better yield and stability have been described. It also includes different methods used for the characterization and analysis of gold nanoparticles, viz. UV-visible spectroscopy, Fourier transform infrared spectroscopy, X ray diffraction spectroscopy, scanning electron microscopy, ransmission electron microscopy, atomic force microscopy, electron dispersive X ray, X ray photoelectron spectroscopy and cyclic voltametry. The different mechanisms involved in microbial synthesis of gold nanoparticles have been discussed. The information related to applications of microbially synthesized gold nanoparticles and patents on microbial synthesis of gold nanoparticles has been summarized.
Materials, May 18, 2016
Biofilms are the cause of 80% of microbial infections. Acinetobacter species have emerged as mult... more Biofilms are the cause of 80% of microbial infections. Acinetobacter species have emerged as multi-and pan-drug-resistant bacteria and pose a great threat to human health. These act as nosocomial pathogens and form excellent biofilms, both on biotic and abiotic surfaces, leading to severe infections and diseases. Various methods have been developed for treatment and control of Acinetobacter biofilm including photodynamic therapy, radioimmunotherapy, prophylactic vaccines and antimicrobial peptides. Nanotechnology, in the present scenario, offers a promising alternative. Nanomaterials possess unique properties, and multiple bactericidal mechanisms render them more effective than conventional drugs. This review intends to provide an overview of Acinetobacter biofilm and the significant role of various nanoparticles as anti-biofouling agents, surface-coating materials and drug-delivery vehicles for biofilm control and treatment of Acinetobacter infections.
Journal of Hazardous Materials, Jul 1, 2011
Phytoremediation is considered as an effective viable alternative to remediate the contaminated s... more Phytoremediation is considered as an effective viable alternative to remediate the contaminated sites, industrially hazardous chemicals and other toxic pollutants. This bioremediation option offers a safe, cheap and eco friendly alternative to existing physical and chemical remediation technologies as well as other biological sources. The wall paint preservatives consist of several harmful and carcinogenic compounds causing serious environmental concerns. In the present study, an actively growing Blumea malcolmii Hook cell suspensions were established successfully on MS+CM (20%) +2,4-D (5 mg l(-1))+Gln (100 mg l(-1))+sucrose (3%) and were used to detoxify a paint preservative Troysan S 89 (a mixture of carbendazim, diuron and ochthilinone). FTIR and UV spectral analytical studies revealed the phytotransformation of Troysan S 89 by Blumea cell suspension cultures. The non-toxic nature of the products formed after phytotransformation was confirmed by phytotoxicity, cytogenotoxicity while non-carcinogenic nature by Ames tests. The novelty of the present study is effective communal degradation of a mixture of three toxicants in Troysan S 89 by cell suspension cultures of Blumea. This work suggested that Blumea cell suspensions might be able to contribute to the wider and safer application of phytoremediation.
Biotechnology and Bioprocess Engineering, Feb 1, 2011
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Papers by Utkarsha Shedbalkar