Functionalized nanoencapsulated Curcuma longa essential oil in chitosan nanopolymer and their application for antioxidant and antimicrobial efficacy.

The present study reports on the encapsulation of Curcuma longa (L.) essential oil (CLEO) in chitosan nanopolymer as a novel nanotechnology preservative for enhancing its antibacterial, antifungal, and mycotoxin inhibitory efficacy. GC-MS analysis of CLEO showed the presence of α-turmerone (42.6 %) and ß- turmerone (14.0 %) as the major components. CLEO-CSNPs were prepared through the ionic-gelation technique and confirmed by TEM micrograph, DLS, XRD, and FTIR. In vitro, bactericidal activity of CLEO-CSNPs at a concentration of 100 µg/mL showed significant antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, which mostly rely on ROS production and depend on its penetration and interaction with bacterial cells. Furthermore, the CLEO-CSNPs during in vitro investigation against F. graminearum completely inhibited the growth and zearalenone and deoxynivalenol production at 0.75 µL/mL, respectively. Further, CLEO-CSNPs enhanced antioxidant activity against DPPH• and ABTS•+ with IC50 values 0.95 and 0.66 µL/mL, respectively, and without any negative impacts on germinating seeds were observed during the phytotoxicity investigation. Overall, experiments concluded that encapsulated CLEO enhances antimicrobial inhibitory efficiency against stored foodborne pathogens.

Nanoencapsulation of garlic essential oil using chitosan nanopolymer and its antifungal and anti-aflatoxin B1 efficacy in vitro and in situ.

The present study investigated the comparative efficacy of garlic essential oil (GEO) and its nanoencapsulated within chitosan nanomatrix (GEO-CSNPs) as a novel preservative for the protection of stored food commodities from fungal infestations, aflatoxin B1 (AFB1) contamination and lipid peroxidation against a toxigenic strain of Aspergillus flavus. GC-MS examination of GEO showed the presence of allyl methyl tri-sulfide (23.10 %) and diallyl sulfide (19.47 %) as the major components. GEO-CSNPs were characterized through TEM micrograph, DLS, XRD, and FTIR instrumentation. During the in-vitro investigation, GEO-CSNPs at 1.0 µL/mL dose completely inhibited the growth of A. flavus while preventing the synthesis of AFB1 at 0.75 µL/mL compared to the pure GEO. The biochemical analysis reveals that A. flavus exposed to GEO-CSNPs significantly changed its ergosterol level, ions leakage, mitochondrial membrane potential (MMP), and antioxidant system. Additionally, GEO-CSNPs exhibited enhanced antioxidant activity against DPPH compared with GEO. Likewise, during in-situ experiments on A. hypogea GEO-CSNPs MIC and 2 MIC concentration prohibited fungal development, AFB1 synthesis, and lipid peroxidation or inflicting any negative impacts on germinating seeds. Overall, investigations concluded that GEO-CSNPs could be used as a novel preservative agent to improve the shelf life of stored food commodities.

Microscopy-based morphological characterization of rugose spiraling whitefly, (Aleurodicus rugioperculatus Martin)-an exotic pest on coconut in India.

Precise identification of exotic whiteflies is a prerequisite to curb the invasive potential on to a new geographical location and to evolve effective management strategies. Conventionally, whitefly taxonomy is based on the description of the fourth-instar nymph or puparium, however, in the current investigation egg to adult morphology along with morphometrics of rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin was critically analyzed and various morphological characteristics were illustrated. The morphometric analysis revealed that in the immature life stages of the pest, the length: width ratio decreased with each successive life stage, such as the egg, first, second, third, and fourth instar (2.472 ± 0.071, 1.913 ± 0.020, 1.550 ± 0.045, 1.297 ± 0.034, and 1.174 ± 0.058 mm), respectively. Across different nymphal instars, the shape of lingula was greatly modified from tongue-like to triangle-shaped. The number and distribution of compound pores also vary among the different nymphal stages. The ultra-structures of the antenna through electron-microscopy depicted finer details of sensory cones. The modulation in the shape and the structural arrangement of microtrichia on the plate was illustrated. The study indicated accurate diagnosis of various stages of RSW for effective interception of goods at quarantine stations and thus preventing the entry of exotic pests into the country. RESEARCH HIGHLIGHTS: Microscopy-based (light and scanning electron microscopy) morphological characterization of rugose spiraling whitefly, (Aleurodicus rugioperculatus Martin).

Biogenic preparation of ZnO, CaO, and ZnO-CaO nanocomposites and its influence on agro-morphological characteristics of mung bean.

In this study, nanomaterials (ZnO and CaO) and ZnO-CaO nanocomposites (Zn25Ca75O; Zn50Ca50O; Zn75Ca25O) were prepared using co-precipitation method and physico-chemically characterized by XRD, FT-IR, and SEM with EDAX analysis. The XRD pattern of ZnO nanomaterials exhibits hexagonal wurtzite structure and CaO nanomaterials exhibit face-centered cubic (FCC) structure whereas nanocomposites (Zn75Ca25O, Zn50Ca50O, Zn25Ca75O) exhibit both hexagonal phase of ZnO and cubic phase of CaO. The SEM images of ZnO-CaO nanocomposites show the well-distributed clusters composed of ZnO and CaO nanoparticles with most of the particles are spherical and some of the particles are rod- and cubic-like morphology. Furthermore, nanomaterials and nanocomposites were used as nano-seed priming agents to assess the seed germination and seedling growth parameters of mung beans. Among the nano-seed priming agents, 500 ppm concentration of the nanocomposite (Zn50Ca50O) showed significant enhancement of germination (100%) and shoot length (11.7 cm), root length (8.9 cm), and vigor index (1910) than other nanomaterials and nanocomposites.

Influence of nanoscale micro-nutrient α-Fe2O3 on seed germination, seedling growth, translocation, physiological effects and yield of rice (Oryza sativa) and maize (Zea mays).

In the present study, nanoscale micronutrient iron (α-Fe2O3) has been prepared via co-precipitation using marine macro alga Turbinaria ornata. The nanoscale micronutrient iron has been used as priming agent for enhancing seed germination, seed quality, uptake, translocation, physiological effects and yield level of rice and maize crops. The physico-chemical characterization techniques results showed the successful preparation of nanoscale micronutrient iron. Seeds primed with nanoscale micronutrient iron at 25 mg/L significantly enhanced the seed germination and seedling parameters in comparison with conventional hydro-priming. ROS production in germinating nano-primed seeds of rice and maize enhanced the seed germination better than the conventional hydro-priming. Uptake and distribution of nanoscale micronutrient iron in rice and maize seedlings were studied using HR-SEM & ICP-MS analysis. Foliar application of low concentration (10 mg/L) nanoscale micronutrient iron under field conditions significantly increased the chlorophyll content, yield attributes of rice and maize crops.

Ultra-structural and physico-chemical characterization of eggs and egg hairs (setae) of the new invasive pest, fall armyworm, Spodoptera frugiperda (J. E. Smith) in India: A first report.

In this study, we report first time in India on the morphology, ultra-architectural pattern of the chorion in the egg and egg hair (setae). Further, physico-chemical characterizations of egg hairs (setae) were studied in the new invasive pest, fall armyworm, Spodoptera frugiperda. The egg is dome shaped with flattened base and curves upward to a broadly rounded point at the apex. HR-SEM micrographs revealed the surface ultrastructure of eggs chorion and shows structural elements of a marked rosette of petals surround the micropyle followed by micropylar rosette region around the micropyle plate. There was a small single micropylar opening along with 9 micropylar rosette cells and 13 micropylar rosette zones present near to the micropylar pit. In the egg the first order ribs were absent, but around 58-60 numbers of second order ribs were present. All the ventral and lateral cells of the eggs are connected by 19-22 cross striae and not forming a grid pattern, but joints with the longitudinal ribs at several of angles and totally 1,277-1,495 convex cells present at the egg's surface. The physico-chemical characteristics of egg hairs were studied using Fourier transform infrared (FT-IR) and thermogravimetric analysis (TGA) analysis. TGA results show that three weight losses occurred at 142, 418, and 880°C, respectively. FT-IR confirms the presence of amides, sulfoxide, and nitro compounds in egg hairs (setae).