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Antibacterial activity of iron oxide nanoparticles synthesized by co-precipitation technology against Bacillus cereus and Klebsiella pneumoniae

Ansari S. A., Oves M., Satar R., Khan A., Ahmad S. I., Jafri M. A., Zaidi S. K., Algahtani M. H.

Polish Journal of Chemical Technology

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2017

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Vol. 19, nr 4

110--115

EN

The present study investigates the synthesis and characterization of iron oxide nanoparticles (Fe3 O4 -NPs) for their antibacterial potential against Bacillus cereus and Klebsiella pneumonia by modified disc diffusion and broth agar dilution methods. DLS and XRD results revealed the average size of synthesized Fe3 O4 -NPs as 24 nm while XPS measurement exhibited the spin-orbit peak of Fe 2p3/2 binding energy at 511 eV. Fe3 O4 -NPs inhibited the growth of K. pneumoniae and B. cereus in both liquid and soild agar media, and displayed 26 mm and 22 mm zone of inhibitions, respectively. MIC of Fe3 O4 -NPs was found to be 5 μg/mL against these strains. However, MBC for these strains was observed at 40 μg/mL concentration of Fe3 O4 -NPs for exhibiting 40–50% loss in viable bacterial cells and 80 μg/mL concentration of Fe3 O4 -NPs acted as bactericidal for causing 90–99% loss in viability. Hence, these nanoparticles can be explored for their additional antimicrobial and biomedical applications.

2

Investigating the antibacterial potential of agarose nanoparticles synthesized by nanoprecipitation technology

Satar R., Lizhar S.A., Rasool M., Pushparaj P.N., Ansari S. A.

Polish Journal of Chemical Technology

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2016

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Vol. 18, nr 2

9--12

EN

Herein, an effort was made to investigate the antibacterial potential of agarose nanoparticles (ANPs) and poly(quaternary ammonium) modifi ed ANPs (mANPs) against Escherichia coli (gram-negative bacterium) and Staphylococcus aureus (gram positive bacterium) in liquid systems as well as on agar plates. ANPs were synthesized by nanoprecipitation technology and characterized by XRD, TEM, TGA, DTA and DLS. The particle size estimated was 30 nm while atomic force microscopy was used to observe the interaction of ligand on ANPs. Antimicrobial characterization was monitored by colony forming units (CFU) as a function of ANPs concentration on agar plates. It was observed that ANPs showed 15 x 109/ml CFU after 24 hours of incubation at 20 mM ANPs concentration while the modified ANPs exhibited 21 x 109/ml CFU under similar incubation conditions. Moreover, zone of inhibition (ZOI) was 2.9 and 3.8 cm, respectively for E. coli by ANPs at 0.2 and 0.4 mM, respectively while it was 3.2 and 3.8 cm respectively by modified ANPs under similar conditions. Similarly, ZOI for S. aureus by ANPs at 0.2 and 0.4 mM was observed at 3.1 and 4.0 cm, respectively, while these values were 3.5 and 4.1 cm, respectively for modified ANPs under similar incubation conditions.

3

Immobilization of Aspergillus oryzae Β galactosidase on concanavalin A-layered calcium alginate-cellulose beads and its application in lactose hydrolysis in continuous spiral bed reactors

Ansari S. A, Husain Q.

Polish Journal of Chemical Technology

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2011

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Vol. 13, nr 4

15-20

EN

In this study, Aspergillus oryzae Β galactosidase was immobilized on concanavalin A layered calcium alginate-cellulose beads as a bioaffi nity support. Immobilized enzyme showed a remarkable broadening in temperature-activity profi les as compared to the native enzyme and exhibited 65% activity in the presence of 5% galactose. Michaelis constant (Km) was 2.57 mM and 5.38 mM for the free and the immobilized Β galactosidase, respectively. Crosslinked Β galactosidase showed greater catalytic activity in the presence of Mg2+ and was more stable during storage at 4°C for 6 weeks. Immobilized enzyme hydrolyzed 67% lactose in milk in 8 h and 85% lactose in whey in 9 h in the stirred batch process at 50oC. The continuous hydrolysis of lactose by crosslinked Β galactosidase in spiral bed reactor exhibited 93% and 88% hydrolysis of lactose at flow rate of 20 ml/h and 30 ml/h, after 1 month operation, respectively.