Nanotechnology is currently gaining immense attention to combat food borne bacteria, and biofilm. Diabetes is a common metabolic disease affecting majority of people. A better therapy relies on phytomediated nanoparticle synthesis. In this study, W. somnifera leaf extract-assisted ZnO NPs (Ws-ZnO NPs) was synthesized and characterized. From HR-TEM analysis, it has been found that the hexagonal wurtzite particle is 15.6 nm in size and − 12.14 mV of zeta potential. A greater antibacterial effect of Ws-ZnO NPs was noticed against E. faecalis and S. aureus at 100 µg mL−1. Also, the biofilm of E. faecalis and S. aureus was greatly inhibited at 100 µg mL−1 compared to E. coli and P. aeruginosa. The activity of α-amylase and α-glucosidase enzyme was inhibited at 100 µg mL−1 demonstrating its antidiabetic potential. The larval and pupal development was delayed at 25 µg mL−1 of Ws-ZnO NPs. A complete mortality (100%) was recorded at 25 µg mL−1. Ws-ZnO NPs showed least LC50 value (9.65 µg mL−1) compared to the uncoated ZnO NPs (38.8 µg mL−1) and leaf extract (13.06 µg mL−1). Therefore, it is concluded that Ws-ZnO NPs are promising to be used as effective antimicrobials, antidiabetic and insecticides to combat storage pests.
Secondary metabolites such as antibiotics are typically produced by actinomycetes as a response to growth limiting stress conditions. Several studies have shown that secondary metabolite production is correlated with changes observed in actinomycete pellet morphology. Therefore, we investigated the correlation between the production of balhimycin and the spatio-temporal distribution of live and dead cells in pellets of Amycolatopsis balhimycina in submerged cultures. To this end, we used laser scanning confocal microscopy to analyze pellets from balhimycin producing and nonproducing media containing 0.2 and 1.0 g l?1 of potassium di-hydrogen phosphate, respectively. We observed a substantially higher fraction of live cells in pellets from cultures yielding larger amounts of balhimycin. Moreover, in media that resulted in no balhimycin production, the pellets exhibit an initial death phase which commences from the centre of the pellet and extends in the radial direction. A second growth phase was observed in these pellets, where live mycelia are seen to appear in the dead core of the pellets. This secondary growth was absent in pellets from media producing higher amounts of balhimycin. These results suggest that distribution of live and dead cells and its correlation with antibiotic production in the non-sporulating A. balhimycina differs markedly than that observed in Streptomycetes.相似文献
Airway mucin secretion is important pathophysiologically and as a model of polarized epithelial regulated exocytosis. We find the trafficking protein, SNAP23 (23-kDa paralogue of synaptosome-associated protein of 25 kDa), selectively expressed in secretory cells compared with ciliated and basal cells of airway epithelium by immunohistochemistry and FACS, suggesting that SNAP23 functions in regulated but not constitutive epithelial secretion. Heterozygous SNAP23 deletant mutant mice show spontaneous accumulation of intracellular mucin, indicating a defect in baseline secretion. However mucins are released from perfused tracheas of mutant and wild-type (WT) mice at the same rate, suggesting that increased intracellular stores balance reduced release efficiency to yield a fully compensated baseline steady state. In contrast, acute stimulated release of intracellular mucin from mutant mice is impaired whether measured by a static imaging assay 5 min after exposure to the secretagogue ATP or by kinetic analysis of mucins released from perfused tracheas during the first 10 min of ATP exposure. Together, these data indicate that increased intracellular stores cannot fully compensate for the defect in release efficiency during intense stimulation. The lungs of mutant mice develop normally and clear bacteria and instilled polystyrene beads comparable to WT mice, consistent with these functions depending on baseline secretion that is fully compensated. 相似文献
Farinocystis tribolii multiplied only in the fatbody of Tribolium castaneum larvae. In the advanced stages of infection, the fatbody was destroyed and the albuminoid granules were completely depleted. Larvae in late stages of infection were “C” shaped. Diseased pupae were flat and straight with the head and mouth parts not completely flexed with the pupal body. Infected pupae failed to develop into adults. Heavily infected adults were distended. Larvae of third, fourth, and fifth instars, although succumbing to the infection ultimately, continued to live even after the healthy larvae of the same age had entered pupation, indicating a prolongation of larval period. Molting was either affected or delayed in infected insects. F. tribolii infection induced a juvenile hormonal effect producing larval-pupal and pupal-adult intermediate forms. Ether extract of spores of F. tribolii when applied on pupae of T. castaneum and final instar nymphs of Dysdercus cingulatus produced adultoids. 相似文献
The structural and growth polarities of centrosomal and chromosomal microtubules were studied by analyzing the kinetics of growth of these microtubules and those initiated by flagellar seeds. By comparing rates of elongation of centrosomal and flagellar-seeded microtubules, we determined whether the centrosomal microtubules were free to grow at their plus ends only, minus ends ony, or at both ends. Our results show that centrosomal microtubules elongate at a rate corresponding to the addition of subunits at the plus end only. The depolymerization rate was also equivalent to that for the plus end only. Chromosomal microtubule elongation was similar to the centrosome-initiated growth. Since the data do not support the hypothesis that both ends of these spindle microtubules are able to interact with monomer in solution, then growth must occur only distal or only proximal to the organizing centers, implying tha the opposite ends in unavailable for exchange of subunits. Experiments with flagellar-seeded microtubules serving as internal controls indicated that the inactivity of the minus end could not be accounted for by a diffusible inhibitor, suggesting a structural explanation. Since there is no apparent way in which the distal ends may be capped, whereas the proximal ends are embedded in the pericentriolar cloud, we conclude that centrosomal microtubules are oriented with their plus ends distal to the site of nucleation. A similar analysis for chromosomal microtubules suggests that they too must be oriented with their plus ends distal to the site of initiation. 相似文献
The white halo fungus, Cephalosporium lecanii, was highly effective in the control of the coffee green bug, Coccus viridis, under field conditions. With two fortnightly applications of 16 × 106 spores/ml, it caused the maximum mortality (73.1%) of the bugs 2 weeks after second application. The mortality rate was increased in the same count to 97.6% when Tween 20 (0.05%) was added to the spore suspension. Addition of starch, Lerolat N 100, Erkentrol, and Wannin to the spore suspension also increased the pathogenicity of the fungus. Among the three insecticides tested along with the fungus, 0.225% Orthene and 0.1% DDT failed to increase the mortality rate of the green bugs while 0.1% BHC hampered the effectiveness of the fungus greatly. In another trial, the fungus was applied at five different dosages and 16 × 106 spores/ml was found adequate to cause a 77.9% mean mortality. The fungus was more effective as high-volume spray than as a low-volume spray. The pathogen, when tested in a drought period, was comparatively less effective, and addition of the humectant glycerol increased the mortality of the bugs due to fungus infection. 相似文献
Competition between granulosis virus (GV) and the larval parasite,Sturmiopsis inferens Tns. (Tachinidae: Diptera), was studied in 3rd — and 4th — instar larvae of the sugarcane shoot borer,Chilo infuscatellus Snellen (Crambidae: Lepidoptera), under laboratory conditions. Mortality due to GV infection and parasitization was 76.8 and 47.6 per cent, respectively,
when they were tested separately. But when hosts were infected simultaneously with microfeeding of GV and larval parasite,
a significantly low parasitism (5.5%) was obtained compared to 74.8 per cent mortality by GV infection. When the larvae were
microfed with the GV 6 days after inoculation with parasitic maggots, mortality due to the virus was reduced significantly
to 20.5 per cent, but when the maggot inoculation was preceded by virus microfeeding 6 days before, parasitization was unsuccessful,
while 75% of larvae died of virus. Results obtained from field — collected larvae also showed that significantly more parasite
puparia were recovered from healthy larvae than from virus — infected larvae. Similar differences in parasitization were not
obtained in the case of healthy or virus — infected pupae.
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