BITS Faculty Publications
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Item Deciphering temporal variations in the ultrastructure and chemical composition of leaf cuticular wax in xerophytic plants(Springer, 2025-12) Panwar, JitendraCuticular wax forms a protective outer layer on the aerial surfaces of land plants, shielding them against water loss and biotic stressors like microbial agents. This study investigates the seasonal variations in cuticular wax micromorphology, thickness, quantity and composition between two xerophytic species, Calotropis procera and Salvadora persica growing in the Indian Thar Desert. Microscopic analyses revealed distinct surface wax morphologies between the two species, with ovate crystalloids on C. procera and platelet-like aggregates on S. persica. Confocal microscopy showed a thinner cuticle layer in C. procera (~ 2 μm) in comparison to S. persica (~ 2 to 7 μm). Both species exhibited the highest wax content during the summer season, aligning with peak environmental stress conditions. Chemical analysis indicated seasonal shifts in major wax classes, with a predominance of alkanes and terpenoids during the high-temperature periods. Despite similar compositional trends across seasons, the two species displayed contrasting micromorphological patterns, highlighting species-specific adaptations. These findings underscore the functional significance of cuticular wax in enhancing drought resilience and thermal tolerance in xerophytic plants, offering valuable insights for understanding plant survival strategies in arid ecosystems.ccccccccccccccccccItem Unveiling the potential of Aspergillus terreus SJP02 for zinc remediation and its driving mechanism(Springer Nature, 2025-01) Verma, Sanjay Kumar; Gupta, Suresh; Panwar, JitendraIn present study, 15 morphologically different fungi isolated from rhizopheric soils of an industrial area were screened for their Zn2+ removal efficiency from aqueous solution. Isolate depicting highest potential was molecularly identified as Aspergillus terreus SJP02. Effect of various process parameters viz. biosorbent dose, contact time, temperature, agitation rate, pH and initial Zn2+ concentration on the fungal sorption capacity were studied. The biosorbent exhibited maximum Zn2+ sorption capacity of 10.7 ± 0.2 mg g− 1 in 60 min. Desorption studies showed 71.46% Zn2+ recovery rate in 120 min with 0.01 N HNO3, indicating efficient metal recovery for reuse and subsequent reutilization of spent mycosorbents. Acid digestion study suggested adsorption being the primary mechanism accounting for 87% Zn2+removal. It was further confirmed by the FE-SEM and EDX analysis. FTIR analysis suggested involvement of amino, hydroxyl, carbonyl, and phosphate functional groups of fungal cell wall in adsorption. The experimental results were in accordance with the tested isotherm and kinetic models, and suggested the role of physical adsorption for Zn2+ removal. Noteworthy, the present study showed better sorption capacity in considerably shorter equilibration time compared to previous reports and advocate potential utilization of A. terreus SJP02 for bioremediation of Zn2+ contaminated wastewater at industrial scale.Item Chemiresistive urea sensor based on a composite film of Activated charcoal and Zinc Oxide(IEEE, 2024) Mishra, Puneet; Gupta, Navneet; Panwar, Jitendra; Mathur, Hitesh DattDetection of nitrogen content in the form of urea is essential as it confirms its fertility for agricultural practices. Herein, a report on a simple microwave decomposition method for the synthesis of hybrid nanomaterial (Zinc Oxide and Activated Charcoal) that shows a maximum sensitivity of ~87% at 100mM urea concentration with response time and recovery time of 6 min and 80 min, respectively. The urea sensing mechanism with pre-adsorbed oxygen ions on the surface of the composite was verified by measuring the change in intensity of CO2 signal upon exposure to urea solution using FTIR. Thus, the composite film acts as a low-cost non-enzymatic chemiresistive urea sensor with good sensitivity and reproducibility.Item Functionalized Cu-based metal oxide nanoparticles with enhanced Cd+2 adsorption capacity and their ecotoxicity assessment by molecular docking(Elsevier, 2022-04) Gupta, Suresh; Panwar, JitendraIn the present study, synthesis of eco-friendly Cu-based metal oxides nanoparticles [CuO, Cu2O, and CuO&Cu2O nanoparticles (NPs)] without and with functionalization with Diethylene glycol (DEG) has been demonstrated. The synthesized NPs were screened for their ability to adsorb multiple heavy metal ions from an aqueous solution. Based on the maximum Cadmium (Cd+2) ion adsorption capacity, functionalized Cu2O (fCu2O) NPs were selected for the detailed characterization and batch studies. The average size of fCu2O NPs was found to be 57.4 ± 6.14 nm in comparison to NPs without capping (72.6 ± 5.19 nm). The experimental parameters viz. contact time, initial pH, and initial concentration were optimized, and the obtained results were interpreted using standard isotherms and kinetic models. The maximum Cd+2 adsorption on fCu2O NPs was observed at initial solution pH 7. The adsorption of Cd+2 was found to be decreased at acidic pH due to the protonation of functional groups present on the NPs surface. A maximum Cd+2 adsorption capacity of 204 ± 6.2 mg g−1 was obtained from the Langmuir adsorption isotherm. The crystal structure of NPs was prepared and docked with the protein targets of selected soil microbes in order to determine their ecotoxicity. The obtained results showed that NPs exhibited low affinity towards protein targets in comparison to the standard used. It suggests that NPs have less impact on the functionality of soil microbes and are thus safe for their disposal into the soil micro-environment.Item Does silver in different forms affect bacterial susceptibility and resistance? A mechanistic perspective(ACS, 2022-01) Panwar, JitendraThe exceptional increase in antibiotic resistance in past decades motivated the scientific community to use silver as a potential antibacterial agent. However, due to its unknown antibacterial mechanism and the pattern of bacterial resistance to silver species, it has not been revolutionized in the health sector. This study deciphers mechanistic aspects of silver species, i.e., ions and lysozyme-coated silver nanoparticles (L-Ag NPs), against E. coli K12 through RNA sequencing analysis. The obtained results support the reservoir nature of nanoparticles for the controlled release of silver ions into bacteria. This study differentiates between the antibacterial mechanism of silver species by discussing the pathway of their entry in bacteria, sequence of events inside cells, and response of bacteria to overcome silver stress. Controlled release of ions from L-Ag NPs not only reduces bacterial growth but also reduces the likelihood of resistance development. Conversely, direct exposure of silver ions, leads to rapid activation of the bacterial defense system leading to development of resistance against silver ions, like the well-known antibiotic resistance problem. These findings provide valuable insight on the mechanism of silver resistance and antibacterial strategies deployed by E. coli K12, which could be a potential target for the generation of aim-based and effective nanoantibiotics.Item One-pot synthesis of metal oxide-clay composite for the evaluation of dye removal studies: Taguchi optimization of parameters and environmental toxicity studies(Springer, 2022-10) Panwar, Jitendra; Gupta, SureshThe present study demonstrates the synthesis of eco-friendly metal oxide-clay composites (MgO-clay and CaO-clay) with phytochemical functionalization. The physical and chemical properties of prepared composites were characterized using standard techniques viz. scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The effect of pH on the dye adsorption capability of the synthesized composites was studied. The adsorption of an anionic dye methyl orange (MO) and a cationic due methylene blue (MB) was favored in the acidic and basic regions, respectively. The Taguchi design approach was adopted for the removal of MO and MB from wastewater using the synthesized composites. The obtained results suggest that initial dye concentration and composite dosage were the most influential parameters in dye removal among all the studied parameters. The adsorption experiments were carried out using MgO-clay and CaO-clay composites with the optimum conditions obtained from Taguchi optimization to validate the predicted response. The experimental parameters viz. the effect of contact time, initial dye concentration, and solution temperature were studied for screened composite (CaO-clay) with optimized conditions. The obtained results were interpreted using standard isotherms and kinetic models. A maximum adsorption capacity of 571 ± 10 and 859 ± 14 mg g−1 was obtained from the Langmuir adsorption isotherm for MO and MB, respectively. Regeneration studies suggested that the CaO-clay composite can be utilized up to 3 cycles with reduced adsorption capacity of the dyes over cycles due to the solid binding nature of dyes on the CaO-clay composite. The fresh and utilized CaO-clay composite were tested for their environmental toxicity analysis using ecologically important soil microorganisms. The obtained results suggested no detrimental effects on soil microbe’s functionality, indicating their threat-free disposal in the soil environment.Item Understanding the in silico aspects of bacterial catabolic cascade for styrene degradation(Wiley, 2022-11) Panwar, JitendraStyrene is a nonpolar organic compound used in very high volume for the industrial scale production of commercially important polymers such as polystyrene resins as well as copolymers like acrylonitrile butadiene styrene, latex, and rubber. These resins are widely used in the manufacturing of various products including single-use plastics such as disposable cups and containers, protective packaging, heat insulation, and so forth. The large-scale utilization leads to the over-accumulation of styrene waste in the environment causing deleterious health risks including cancer, neurological impairment, dysbiosis of central nervous system, and respiratory problems. To eliminate the accumulating waste. Microbial enzyme-based system represents the most environmental friendly and sustainable approach for elimination of styrene waste. However, comprehensive understanding of the enzyme–substrate interaction and associated pathways would be crucial for developing large-scale disposal systems. This study aims to understand the molecular interaction between the protein-ligand complexes of the styrene catabolic reactions by bacterial enzymes of sty operon. Molecular docking analysis for catalytic enzymes namely, styrene monooxygenase (SMO), styrene oxide isomerase (SOI), and phenylacetaldehyde dehydrogenase (PAD) of the bacterial sty operon was carried out with their individual substrates, that is, styrene, styrene oxide, and phenylacetic acid, respectively. The binding energy, amino acids forming binding cavity, and binding interactions between the protein-ligand binding sites were calculated for each case. The obtained binding energies showed a stable association of these complexes indicating the future scope of their utilization for large-scale bioremediation of styrene, and its commercially used polymers and copolymers.Item Unveiling the potential of Lichtheimia ramosa AJP11 for myco-transformation of polystyrene sulfonate and its driving molecular mechanism(Elsevier, 2023-01) Panwar, JitendraPlastic pollution is a major environmental concern due to its deleterious effects on various ecosystems. The limitations and shortcomings of waste management strategies has led to the over-accumulation of plastic waste, mainly comprised of single-use plastics, such as polystyrene (PS). Considering the advantages of biotransformation over the other plastic disposal methods, it has become a major focus of the modern research. Biotransformation of plastics involves its microbial hydrolysis into short chain oligomers and monomers that are eventually assimilated as carbon source by the microbes leading to the release of CO2. As fungi are known to possess multifarious and highly regulated enzyme system capable of utilizing diverse nutrient sources, the present study explored the potential of Lichtheimia ramosa AJP11 towards myco-transformation of polystyrene sulfonate (PSS), a structural analogue of polystyrene (PS). During the 30-day incubation period of L. ramosa AJP11 in minimal salt medium (MSM)+1% PSS, the fungus showed 41.6% increment in its fresh weight biomass, indicating the utilization of PSS as sole carbon source. Further analysis revealed the generation of various reaction intermediates such as alkanes and fatty acids, crucial for the continuum of fungal metabolic pathways. Moreover, detection of PS oligomers such as cyclohexane and 2,4-DTBP confirmed the myco-transformation of PSS. The extracellular fungal protein profile showed considerable overexpression of a 14.4 kDa protein, characterized to be a hydrophobic surface binding (Hsb) protein, which is hypothesized to adsorb onto the PSS to facilitate its transformation. Further, in silico analysis of Hsb protein indicated it to be an amphiphilic α-helical protein with ability to bind styrene sulfonate unit via both hydrogen and hydrophobic interactions, with a binding energy of −5.02 kcal mol−1. These findings open new avenues for over expression of Hsb under controlled reactor conditions to accelerate the PS waste disposal.Item Phylloplane fungus Curvularia dactyloctenicola VJP08 effectively degrades commercially available PS product(Elsevier, 2024-02) Panwar, Jitendra; Gupta, SureshPolystyrene (PS), a widely produced plastic with an extended carbon (C–C) backbone that resists microbial attack, is produced in enormous quantities throughout the World. Naturally occurring plasticizers such as plant cuticle and lignocelluloses share similar properties to synthetic plastics such as hydrophobicity, structural complexity, and higher recalcitrance to degradation. In due course of time, phytopathogenic fungi have evolved strategies to overcome these limitations and utilize lignocellulosic waste for their nutrition. The present investigation focuses on the utilization of phylloplane fungus, Curvularia dactyloctenicola VJP08 towards its ability to colonize and degrade commercially available PS lids. The fungus was observed to densely grow onto PS samples over an incubation period of 30 days. The morphological changes showcased extensive fungal growth with mycelial imbrication invading the PS surface for carbon extraction leading to the appearance of cracks and holes in the PS surface. It was further confirmed by EDS analysis which indicated that carbon was extracted from PS for the fungal growth. Further, 3.57% decrease in the weight, 8.8% decrease in the thickness and 2 °C decrease in the glass transition temperature (Tg) confirmed alterations in the structural integrity of PS samples by the fungal action. GC-MS/MS analysis of the treated PS samples also showed significant decrease in the concentration of benzene and associated aromatic derivatives confirming the degradation of PS samples and subsequent utilization of generated by-products by the fungus for growth. Overall, the present study confirmed the degradation and utilization of commercially available PS samples by phylloplane fungus C. dactyloctenicola VJP08. These findings establish a clear cross-assessment of the phylloplane fungi for their prospective use in the development of degradation strategies of synthetic plastics.Item Remediation of multifarious metal ions and molecular docking assessment for pathogenic microbe disinfection in aqueous solution by waste-derived Ca-MOF(Springer, 2024-02) Panwar, Jitendra; Gupta, SureshThe present study demonstrates an eco-friendly and cost-effective synthesis of calcium terephthalate metal–organic frameworks (Ca-MOF). The Ca-MOF were composed of metal ions (Ca2+) and organic ligands (terephthalic acid; TPA); the former was obtained from egg shells, and the latter was obtained from processing waste plastic bottles. Detailed characterization using standard techniques confirmed the synthesis of Ca-MOF with an average particle size of 461.9 ± 15 nm. The synthesized Ca-MOF was screened for its ability to remove multiple metal ions from an aqueous solution. Based on the maximum sorption capacity, Pb2+, Cd2+, and Cu2+ ions were selected for individual parametric batch studies. The obtained results were interpreted using standard isotherms and kinetic models. The maximum sorption capacity (qm) obtained from the Langmuir model was found to be 644.07 ± 47, 391.4 ± 26, and 260.5 ± 14 mg g−1 for Pb2+, Cd2+, and Cu2+, respectively. Moreover, Ca-MOF also showed an excellent ability to remove all three metal ions simultaneously from a mixed solution. The metal nodes and bonded TPA from Ca-MOF were dissociated by the acid dissolution method, which protonated and isolated TPA for reuse. Further, the crystal structure of Ca-MOF was prepared and docked with protein targets of selected pathogenic water-borne microbes, which showed its disinfection potential. Overall, multiple metal sorption capability, regeneration studies, and broad-spectrum antimicrobial activity confirmed the versatility of synthesized Ca-MOF for industrial wastewater treatment.