Faculty of Applied Sciences
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Item Biogenic synthesis of zinc oxide nanoparticles mediated by the extract of Terminalia catappa fruit pericarp and its multifaceted applications(American Chemical Society (ACS), 2023-10-09) Fernandes, Cannon Antony; Jesudoss M, Nameeta; Nizam, Aatika; Krishna, Suresh Babu Naidu; Lakshmaiah, Vasantha VeerappaZinc oxide nanoparticles (ZnO-NPs) were bio synthesized by using the pericarp aqueous extract from Terminalia catappa Linn. These NPs were characterized using various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spec troscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM), and XRD studies of the nanoparticles reported mean size as 12.58 nm nanocrystals with highest purity. Further SEM analysis emphasized the nanoparticles to be spherical in shape. The functional groups responsible for capping and stabilizing the NPs were identified with FTIR studies. DLS studies of the synthesized NPs reported ζ potential as −10.1 mV and exhibited stable colloidal solution. These characterized ZnO-NPs were evaluated for various biological applications such as antibacterial, antifungal, antioxidant, genotoxic, biocompatibility, and larvicidal studies. To explore its multidimensional application in the field of medicine. NPs reported a potential antimicrobial activity at a concentration of 200 μg/mL against bacterial strains in the decreasing order of Streptococcus pyogenes > Streptococcus aureus > Streptococcus typhi > Streptococcus aeruginosa and against the fungi Candida albicans. In vitro studies of RBC hemolysis with varying concentrations of NPs confirm their biocompatibility with IC50 value of 211.4 μg/mL. The synthesized NPs’ DPPH free radical scavenging activity was examined to extend their antioxidant applications. The antiproliferation and genetic toxicity were studied with meristematic cells of Allium cepa reported with mitotic index (MI index) of 1.2% at the concentration of 1000 μg/mL. NPs exhibited excellent Larvicidal activity against Culex quinquefasciatus larvae with the highest mortality rate as 98% at 4 mg/L. Our findings elicit the therapeutic potentials of the synthesized zinc oxide NPsItem Differential approach of bioremediation by sclerotium rolfsii towards textile dye(2023-10-05) Samuel, Anthony; Lakshmaiah, , Vasantha Veerappa; Dias, Priyanjali; Praveen, N.; Fernandes, Cannon Antony; Nizam, Aatika; Krishna, Suresh Babu NaiduSynthetic dyes are extensively used in various industries and are one of the major contaminants of industrial effluents. Dyes being xenobiotic, carcinogenic, and toxic there is need for their effective removal and detoxification to conserve water resources. Tremendous research has been carried out to identify potent microorganisms that facilitate bioremediation of these harmful dyes. A static batch culture has proved white rot fungi Sclerotium.rolfsii as an efficient catalyst in bioremediation of textile dyes and to compare their efficiency in decolourisation of two different azo dyes. Studies revealed the organism employ different remedial approach to cationic dye (Malachite green) and anionic dyes (Rose Bengal). Decolourisation of malachite green was a gradual with degradation and bio-transformation to colourless, non-toxic by products while Decolourisation of rose Bengal was quick process of biosorption. S.rolfsii exhibited 89% of decolourisation of malachite green dyes at higher concentration of 900mg/L while 96% for rose Bengal at 900mg/L. The mechanism of dye decolourisation was proposed using the UV Vis spectrophotometry, FTIR, XRD, HPLC and SEM. Microbial toxicity studies confirmed the dye metabolites of degraded malachite green was less toxic compared to original dye. Com- prehensively studies illustrate the sustained application of S. rolfsii as model organism for bioremediation of complex industrial effluents due to its differential bio remedial approach can potentially decolourise or remove various dyes.