ABSTRACT
The effluent contains many harmful microbes which should be eliminated before it is discharged into a water body. Silver nanoparticles (AgNPs) being high-quality significance and have a great impact on this research field as it inhibits microbial proliferation and infection. Therefore, it may use for Bioremediation purposes, our laboratory is fascinated by the production of polymer matrix entrapment silver nanoparticles for in situ bio-remediation purposes. The AgNPs was prepared from sawdust by decoction method. The yellowish solution turns into dark brown colour indicating the formation of AgNPs. A sharp SPR (Surface Plasmon Resonance) band formation in UV-vis spectroscopy scan establishes the formation and stability of silver nanoparticles in an aqueous solution. SEM microphotograph indicated roughly spheroidal structure with (63±3) nm average diameters of newly synthesized AgNp. Polyvinyl alcohol (PVA) is eco-friendly and non-toxic to the environment was chosen for the preparation of polymeric matrix. The non-toxic concentration (1 ?g/mL) of AgNp was dispersed into PVA solution followed by cross-linked with maleic acid. PVA- maleic acid is cross-linked by the formation of an ester bond, whereas silver nanoparticles physically entrap into the cross-linked matrix. The silver nanoparticles were released from the matrix nearly after 10 min of swelling of the composite film. In a microbial assay using E. coli agar medium, PVA-AgNp composite film shows the significant killing of microorganisms. Microbial elimination is measured indirectly by pH measurement and dissolved oxygen concentration measurement of the effluent in situ against RO- water, taken as control. The dissolved oxygen concentration from RO water and effluent water was measured on Day “0” followed by treatment and incubation at the BOD chamber. The treatment with PVA-AgNp composite film reduced the BOD Level and increase dissolved oxygen level simultaneously increasing the quality of water.
ABSTRACT
The ability of a synthetic, aromatic tripeptide, H-Phe-Phe-Phe-OH (FFF) to recognize the double-stranded DNA (dsDNA) has been tested with various biophysical and thermodynamic techniques. From the study, it is established that the peptide can recognize the groove of the ct-DNA and the binding constant value calculated from the isothermal titration calorimetric (ITC) study at 25°C is 9.96 × 103 M-1. From ITC data it is also noticed that the peptide–DNA complexation is favored by positive standard molar entropy contribution (TΔS°) of 13.65 kJ mol−1 and negative standard molar enthalpy contribution (ΔH°) of −9.170 kJ mol−1. The temperature-dependent ITC study also shows that the equilibrium constant value decreases gradually with increasing temperature. However, the standard molar Gibbs energy change exhibits only minor alterations suggesting the occurrence of enthalpy-entropy compensation. The studies reveal the insight into the spectroscopic and thermodynamic prospect of the FFF-ct-DNA interaction in vitro and hold the promise of future applications as DNA targeting drug.