Application of Syzygium aromaticum, Ocimum sanctum, and Cananga odorata essential oils for management of Ochratoxin A content by Aspergillus ochraceus and Penicillium verrucosum: An in vitro assessment in maize grains

172-182The study is directed to establish the minimizing effects of Syzygium aromaticum, Ocimum sanctum, and Cananga odorata essential oils on the growth and ochratoxin A (OTA) level of Aspergillus ochraceus and Penicillium verrucosum in maize grains. S. aromaticum essential oil (SAEO), O. sanctum essential oil (OSEO), and C. odorata essential oil (COEO) were extracted by hydro-distillation technique, and a total of 50, 44, and 48 chemical constituents were identified by gas chromatography-mass spectrometry (GC-MS), respectively.The SAEO and OSEO belong to the chemotype of eugenol, whereas, COEO was found to be the chemotype of thymol, limonene, and α-ylangene. The antifungal activity of essential oils (EOs) was determined by the micro-well dilution technique. The SAEO showed superior antifungal activity compared to OSEO, COEO, and synthetic antifungal agent nystatin, and its minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values against A. ochraceous and P. verrucosum were noticed as 1251 ± 42.32 and 1878 ± 28.47 μg/mL, and 0815 ± 22.69 and 1146 ± 51.19 μg/mL, respectively.The antifungal mechanism of EOs was unveiled by assessing the intracellular reactive oxygen species (ROS), ergosterol content, and membrane integrity. The antifungal investigations found that EOs caused fungal mortality by increasing the intracellular ROS, depleting ergosterol synthesis, and distracting membrane integrity. Finally, antifungal and antimycotoxin activity of EOs was demonstrated in maize grains. The SAEO, OSEO, and COEO have reduced the complete fungal growth and OTA level of A. ochraceous and P.verrucosum correspondingly at 2500 and 2500, 3500 and 2500, and 3500 and 3500 μg/g in maize. The EOs could act asnatural antifungal agents; protect foodstuffs from fungal infection and mycotoxins during storage

Biomimetic of hydroxyapatite with Tridax procumbens leaf extract and investigation of antibiofilm potential in Staphylococcus aureus and Escherichia coli

In the last few decades, hydroxyapatite (HA) has become one of the most highly prized biominerals in the biomedical industry for orthopedic and dental applications. The focus of this research was to synthesize biomimetic HA from Tridax procumbens (TP) leaf extract and investigate their antibiofilm properties. The HA was made using the sol-gel method and the HA-TP biocomposite was made by precipitation method. The d.nm size of HA and HA-TP biocomposite was determined as 193.28 and 258.14 d.nm, respectively. The zeta potential of HA and HA-TP biocomposite was determined as −21.2 and −18.3 mV, respectively, and found highly stable. The FTIR study revealed that phytochemicals of TP were successfully impregnated into HA-TP biocomposite. The HA and HA-TP biocomposite were found spherical and agglomerated from SEM analysis. In HR-TEM analysis, the average diameter of the HA and HA-TP biocomposite were 16.57 – 64.22 nm and 51.71 – 138.68 nm, respectively. According to the EDX analysis, HA is primarily composed of calcium, oxygen, and phosphate, whereas, HA-TP biocomposite is primarily composed of calcium, phosphate, oxygen, and carbon. In the antioxidant assay, the IC50 value (concentration required to scavenge 50% of free radicals) of HA-TP biocomposite was determined as 156.69 ± 14.02 and 180.21 ± 12.84 µg/mL in DPPH and ABTS free radical scavenging assays, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of as-synthesized HA-TP biocomposite against Staphylococcus aureus – ATCC 13565 and Escherichia coli – MTCC 41 were observed as 181.09 ± 21.47 and 317.30 ± 41.03, and 157.59 ± 32.18 and 264.03 ± 21.58 µg/mL, respectively. The as-synthesized HA-TP biocomposite has detrimentally affected the biofilm formation of both the tested bacteria S. aureus – ATCC 13565 and E. coli – MTCC 41. The study concluded that the as-synthesized HA-TP biocomposite could be highly helpful in the biomedical field for alleviating oxidative-stress-related disorders and inhibiting microbial biofilm formation

New insights into method development and characterization of amorphous silica from wheat straw

Amorphous silica, a specialised silicate adsorbent is extensively extracted from agricultural residues for application in various environmental domains. Wheat straws are a rich source of silica that have earlier been overlooked however demand for value addition. The study presents an innovative approach to extracting silica from wheat straw and standardising the extraction process to produce clean product. The sodium silicate solution and the amorphous silica synthesis were obtained by modifying the template mediated sol–gel method. Optimum temperature, concentration and pH were identified for the cleaner production of silica with maximum yield and favourable adsorbent characteristics. The crystallographic properties analysed by the X-Ray Diffraction revealed the amorphous nature of silica extracted from ash at 650 °C for 4 h. The structure of phytolith present in the wheat straw was observed in the form of articulated elongate undulate epidermal phytolith under scanning electron microscopy. The Energy Dispersive X-ray spectrum exhibited higher amount of silica (Si %) of 70.10% with a minimal percentage of potassium (9.96%). The sharp bend at 1025 cm−1 is attributed to the siloxane (Si–O-Si) vibrations in Fourier transform infrared spectroscopic graph of amorphous silica. The specific surface area measurements of amorphous silica showed type II isotherm curve with a hysteresis of H3 type. The optimum conditions derived to produce amorphous silica were 3 M NaOH and 3 M H2SO4 at pH 9

Competitive Sorption of Cu(II), Pb(II) and Hg(II) Ions from Aqueous Solution Using Coconut Shell-Based Activated Carbon

Many adsorbents have been studied for their adsorption properties towards one-component metal ion solutions. However, if these materials are to be used for treating wastewater, their performance has to be determined in multi-component solutions. In the present work, multi-component metal sorption by coconut shell-based activated carbon has been studied using single, binary and ternary systems composed of Cu(II), Pb(II) and Hg(II) ions. The influence of solution pH was also demonstrated. A set of desorption studies was also performed for the same metal ions with the aim of investigating the mechanism involved. It was found that chemisorption, surface chelation and complexation might be a possible metal ion removal mechanism. Scanning electron micrographs (SEM) and the EDAX spectrum of the activated carbon surface before and after equilibration of the adsorbent with the metal ion solution clearly showed the presence of Cu(II), Pb(II) and Hg(II) ions. An attempt was made to quantify the interaction behaviour of the metal ion on the adsorbent and to correlate such observations with the chemical and physical properties of the metal ions. The ability of isotherm models such as those of Freundlich and Langmuir to predict the equilibrium uptake of Cu(II), Pb(II) and Hg(II) ions from one-component, binary and ternary systems was also tested. Both the Langmuir and Freundlich models were found to fit the experimental data well. The applicability of the extended Langmuir model was also evaluated for multi-component systems

Trace Metal Based Eco-Biological and Health Risk Status of Surface Water and Sediments of Noyyal River Basin, Tamil Nadu, India

Pollution in the Noyyal river is a well-known and documented issue and recently, heavy metal contamination has become a serious issue requiring immediate attention. So, to understand the severity of heavy metal contamination in the surface water and sediments of the Noyyal river, a comprehensive study was conducted. About 27 surface water samples and 25 sediment samples were collected at different sites along the Noyyal river. The concentrations of heavy metals were determined using inductively coupled plasma mass spectrometry (ICP-MS). The Noyyal river’s surface water showed significant variations with nickel (Ni), copper (Cu), and zinc (Zn) concentrations exceeding acceptable limits for irrigation and aquatic life. Lead (Pb) concentrations were within acceptable limits for irrigation but potentially harmful to aquatic organisms. Noyyal river sediments also contained varying concentrations of chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), and gallium (Ga). Various assessment indices were employed to assess the eco-biological and human health risks associated with heavy metal contamination. The results highlighted alarming ecological and biological risks due to the accumulation of trace metals. Sediments exhibited high ecological risk (ERI values ranging from 43.81 to 371.43), while surface water samples intended for irrigation and aquatic purposes displayed extreme risks (ERI values exceeding 1200) to agricultural crops and aquatic organisms. The probability of toxicity to aquatic organisms, particularly benthic communities, was over 76% according to the biological risk assessment. The study also identified potential non-carcinogenic risks associated with metals like chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) in the sediments. Moreover, elevated levels of Cr, Ni, and Cu in both sediments and surface water were likely to pose significant carcinogenic risks to exposed adults. Additionally, the heavy metal toxicity load in both surface water and sediments exceeded permissible limits, highlighting the urgent need for efficient removal strategies.</p

Application of Syzygium aromaticum, Ocimum sanctum, and Cananga odorata essential oils for management of Ochratoxin A content by Aspergillus ochraceus and Penicillium verrucosum: An in vitro assessment in maize grains

The study is directed to establish the minimizing effects of Syzygium aromaticum, Ocimum sanctum, and Cananga odorata essential oils on the growth and ochratoxin A (OTA) level of Aspergillus ochraceus and Penicillium verrucosum in maize grains. S. aromaticum essential oil (SAEO), O. sanctum essential oil (OSEO), and C. odorata essential oil (COEO) were extracted by hydro-distillation technique, and a total of 50, 44, and 48 chemical constituents were identified by gas chromatography-mass spectrometry (GC-MS), respectively.The SAEO and OSEO belong to the chemotype of eugenol, whereas, COEO was found to be the chemotype of thymol, limonene, and α-ylangene. The antifungal activity of essential oils (EOs) was determined by the micro-well dilution technique. The SAEO showed superior antifungal activity compared to OSEO, COEO, and synthetic antifungal agent nystatin, and its minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values against A. ochraceous and P. verrucosum were noticed as 1251 ± 42.32 and 1878 ± 28.47 µg/mL, and 0815 ± 22.69 and 1146 ± 51.19 µg/mL, respectively.The antifungal mechanism of EOs was unveiled by assessing the intracellular reactive oxygen species (ROS), ergosterol content, and membrane integrity. The antifungal investigations found that EOs caused fungal mortality by increasing the intracellular ROS, depleting ergosterol synthesis, and distracting membrane integrity. Finally, antifungal and antimycotoxin activity of EOs was demonstrated in maize grains. The SAEO, OSEO, and COEO have reduced the complete fungal growth and OTA level of A. ochraceous and P. verrucosum correspondingly at 2500 and 2500, 3500 and 2500, and 3500 and 3500 µg/g in maize. The EOs could act as natural antifungal agents; protect foodstuffs from fungal infection and mycotoxins during storage

Biomimetic of hydroxyapatite with Tridax procumbens leaf extract and investigation of antibiofilm potential in Staphylococcus aureus and Escherichia coli

755-766In the last few decades, hydroxyapatite (HA) has become one of the most highly priced biominerals in the biomedical industry for orthopedic and dental applications. The focus of this research was to synthesize biomimetic HA from Tridax procumbens (TP) leaf extract and investigate their antibiofilm properties. The HA was made using the sol-gel method and the HA-TP biocomposite was made by precipitation method. The d.nm size of HA and HA-TP biocomposite was determined as 193.28 and 258.14 d.nm, respectively. The zeta potential of HA and HA-TP biocomposite was determined as −21.2 and −18.3 mV, respectively, and found highly stable. The FTIR study revealed that phytochemicals of TP weresuccessfully impregnated into HA-TP biocomposite. The HA and HA-TP biocomposite were found spherical andagglomerated from SEM analysis. In HR-TEM analysis, the average diameter of the HA and HA-TP biocomposite were16.57 – 64.22 nm and 51.71 – 138.68 nm, respectively. According to the EDX analysis, HA is primarily composed ofcalcium, oxygen, and phosphate, whereas, HA-TP biocomposite is primarily composed of calcium, phosphate, oxygen, andcarbon. In the antioxidant assay, the IC50 value (concentration required to scavenge 50% of free radicals) of HA-TPbiocomposite was determined as 156.69 ± 14.02 and 180.21 ± 12.84 μg/mL in DPPH and ABTS free radical scavengingassays, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of as-synthesized HA-TP biocomposite against Staphylococcus aureus – ATCC 13565 and Escherichia coli – MTCC 41 wereobserved as 181.09 ± 21.47 and 317.30 ± 41.03, and 157.59 ± 32.18 and 264.03 ± 21.58 μg/mL, respectively. The as-synthesized HA-TP biocomposite has detrimentally affected the biofilm formation of both the tested bacteria S. aureus –ATCC 13565 and E. coli – MTCC 41. The study concluded that the as-synthesized HA-TP biocomposite could be highlyhelpful in the biomedical field for alleviating oxidative-stress-related disorders and inhibiting microbial biofilm formation

Application of Activated Carbon Derived from Seed Shells of Jatropha curcas for Decontamination of Zearalenone Mycotoxin

In the present study, activated carbon (AC) was derived from seed shells of Jatropha curcas and applied to decontaminate the zearalenone (ZEA) mycotoxin. The AC of J. curcas (ACJC) was prepared by ZnCl2 chemical activation method and its crystalline structure was determined by X-ray diffraction analysis. The crystalline graphitic nature of ACJC was confirmed from the Raman spectroscopy. Scanning electron microscope showed the porous surface morphology of the ACJC surface with high pore density and presence of elemental carbon was identified from the energy dispersive X-ray analysis. From Brunauer–Emmett–Teller (BET) analysis, SBET, micropore area, and average pore diameter of ACJC were calculated as 822.78 (m2/g), 255.36 (m2/g), and 8.5980 (Å), respectively. The adsorption of ZEA by ACJC was accomplished with varying contact time, concentration of ZEA and ACJC, and pH of media. The ACJC has adsorbed the ZEA over a short period of time and adsorption of ZEA was dependent on the dose of ACJC. The effect of different pH on adsorption of ZEA by ACJC was not much effective. Desorption studies confirmed that adsorption of ZEA by ACJC was stable. The adsorption isotherm of ZEA by ACJC was well fitted with Langmuir model rather than Freundlich and concluded the homogeneous process of sorption. The maximum adsorption of ZEA by ACJC was detected as 23.14 μg/mg. Finally, adsorption property of ACJC was utilized to establish ACJC as an antidote against ZEA-induced toxicity under in vitro in neuro-2a cells. The percentage of live cells was high in cells treated together with a combination of ZEA and ACJC compared to ZEA treated cells. In a similar way, ΔΨM was not dropped in cells exposed to combination of ACJC and ZEA compared to ZEA treated cells. Furthermore, cells treated with a combination of ZEA and ACJC exhibited lower level of intracellular reactive oxygen species and caspase-3 compared to ZEA treated cells. These in vitro studies concluded that ACJC has successfully protected the cells from ZEA-induced toxicity by lowering the availability of ZEA in media as a result of adsorption of ZEA. The study concluded that ACJC was a potent decontaminating agent for ZEA and could be used as an antidote against ZEA-induced toxicity