The purpose of the present work is improving stability properties of porcine pancreatic lipase (t... more The purpose of the present work is improving stability properties of porcine pancreatic lipase (triacylglycerol lipase, E.C.3.1.1.3) by immobilization on chitosan/TiO 2 composite beads. The immobilization parameters were initial enzyme concentration (0.5-2 mg/ml), adsorption time (5-25 min), and glutaraldehyde concentration (1-4 % v/v). The optimum temperature (20-60°C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70°C), pH stability (4.0-9.0), and reusability (9 times) were investigated for characterization of immobilized lipase system. The optimum temperatures of free and immobilized lipase were 30°C. The temperature profile of the immobilized lipase was spread over a large area. The optimum pH values for the free lipase and immobilized lipase were found to be 6.5 and 7.5, respectively. The thermal stability of immobilized lipase was evaluated, and it maintained 45 % activity at 70°C. But, at this temperature, soluble lipase protected only 15 % activity. Also, the structural characterization of chitosan/ TiO 2 composite beads was analyzed with scanning electron microscope (SEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and attenuated total reflection Fourier transform infrared spectroscopy analysis (ATR-FTIR). The significance of this study is improving of stability properties of lipase for the industrial usage especially production of biodiesel and dairy products.
Magnetotatic bacteria have been isolated from iron cap belt of Cuddegali Voril Soddo iron ore min... more Magnetotatic bacteria have been isolated from iron cap belt of Cuddegali Voril Soddo iron ore mine. Here magnetic measurement and non magnetic analysis helps to detect biogenic magnetite in soil sample. The cultivation of magnetotactic bacteria was done in modified enrichment medium and incubated at room temperature (25–30 0 C). A short rod of magnetotactic bacteria contained two or more magnetosomes revealed under TEM, having the shape of rounded and irregular. The SEM was used for morphological study of MTB. Energy spectrum analysis with SEM showed that iron oxides were main component of magnetic particles. This study reports the isolation and characterization of magnetotactic bacteria isolated from the mining area of Goa region, India. It also points towards the ability of modified media to support growth of magnetotactic isolates. The result depicts that there is a direct correlation of soil magnetic susceptibility with biogenic magnetite, geology and soil process. The natural way for the synthesis of nanoparticles by microbes, which is potent eco-friendly, green synthesis leads to the development of advance research in nanotechnology. The result gives the direction for future work, that is it can be used as potential heating agent in magnetic fluid hyperthermia (MFH).
A B S T R A C T Nanocrystalline TiO 2 and MWCNTs are important functional materials that have rec... more A B S T R A C T Nanocrystalline TiO 2 and MWCNTs are important functional materials that have received considerable research interest in the last few decade. In this work, the composites of TiO 2 nanoparticles with varying amount of functionalized MWCNTs were prepared by using a solution-based method. The physico-chemical properties of these composites were studied in connection with their antibacterial activity. TiO 2 particles have non-spherical shape with size in the range of 8–15 nm; which were confirmed through TEM analysis and these particles were well hosted on the surface of MWCNTs. The tuning of optical band gap of nanocomposites was studied by using DR UV-visible spectroscopy. The photocatalytic inactivation of Escherichia coli and Staphylococcus aureus using TiO 2-MWCNTs nanocomposites in the presence of visible light (l > 420 nm) has been carried out. These nanocomposites show efficient antibacterial activity under visible light illumination, whereas bare TiO 2 nanoparticles did not show any inhibitory effect on bacteria under visible light exposure. These results suggest that UV light or TiO 2 alone is not effective for photocatalytic disinfection applications. Also, cytotoxicity study reveals that the nanocomposites show better cell viability than bare TiO 2 nanoparticles. Overall, the experimental results suggest that TiO 2-MWCNTs nanocomposites have been developed as efficient antibacterial agents against a wide range of microorganisms to prevent and control the persistence and spreading of bacterial infections.
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Wie... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Wien. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Magnetic adsorption technology of polymer functionalized superparamagnetic nanoparticles is showi... more Magnetic adsorption technology of polymer functionalized superparamagnetic nanoparticles is showing great potential in biomedical applications because of their facile " on and off " state of magnetization. Highly magnetized superparamagnetic nanoparticle based magnetic adsorption technology was employed for the purification of DNA. The core–shell Fe 3 O 4 nanoparticles were synthesized by alkaline precipitation and subsequently coated with silica by sol–gel method. Further, silica coated Fe 3 O 4 nanoparticles functionalized with chitosan were used as an adsorbent for DNA. The surface adsorption of DNA onto the modified nanoparticles was optimized as a function of pH, time and temperature. The adsorption efficiency of Fe 3 O 4 @silica@chitosan nanoparticles was examined by UV visible spectroscopy. Fe 3 O 4 @silica@chitosan nanoparticles with the high adsorption efficiency of $88% and a high elution efficiency of $98% were employed for DNA isolation from human saliva. Agarose gel electrophoresis was used to validate the quality and quantity of DNA isolated from human saliva. Square wave voltammetry was carried out for monitoring the quantitative information about DNA fragment concentration. This method has potential application in the field of bioelectrochemical analysis. The isolation results of genomic DNA from saliva indicated that the Fe 3 O 4 @silica@chitosan nanoparticles have outstanding advantages in operation, selectivity, and capacity over the present existing isolation protocols (phenol–chloroform extraction). Furthermore, it opens up new opportunities in detection and isolation of nucleic acid.
This study for the first time shows the effective utilization and production of chitin monomers a... more This study for the first time shows the effective utilization and production of chitin monomers at laboratory level, with immense potential for its biomedical application. Low molecular weight (LMW) N-acetylglucosamine (GlcNAc) is prepared by depolymerization of chitin using chemical method coupled with a physical separation method. A novel filtration strategy exploiting polysulfone hollow fiber membrane is used for the preparation of GlcNAc particles with 94% yield within 8.5 ± 0.5 h. This high efficiency is analyzed using high-pressure liquid chromatography. The GlcNAc obtained was further analyzed using dynamic light scattering, first derivative Fourier transform infrared spectroscopy, and X-ray diffraction techniques. The antimicrobial properties of GlcNAc, chitin, and GlcNAc/chitin mixture were investigated using minimal inhibitory concentration against S. aureus and E. coli. Bacteriostatic property was exhibited by high molecular weight chitin, while GlcNAc and GlcNAc/chitin mixture (LMW) demonstrated bactericidal activity. Blood biocompatibility below 0.25 g/ml and cytocompatibility with NIH3T3 fibroblast cells and the proliferative efficacy suggested its utilization and suitability of these particles in biological applications.
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