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81.
Marcela Bucekova Ivana Valachova Lenka Kohutova Emanuel Prochazka Jaroslav Klaudiny Juraj Majtan 《Die Naturwissenschaften》2014,101(8):661-670
Antibacterial properties of honey largely depend on the accumulation of hydrogen peroxide (H2O2), which is generated by glucose oxidase (GOX)-mediated conversion of glucose in diluted honey. However, honeys exhibit considerable variation in their antibacterial activity. Therefore, the aim of the study was to identify the mechanism behind the variation in this activity and in the H2O2 content in honeys associated with the role of GOX in this process. Immunoblots and in situ hybridization analyses demonstrated that gox is solely expressed in the hypopharyngeal glands of worker bees performing various tasks and not in other glands or tissues. Real-time PCR with reference genes selected for worker heads shows that the gox expression progressively increases with ageing of the youngest bees and nurses and reached the highest values in processor bees. Immunoblot analysis of honey samples revealed that GOX is a regular honey component but its content significantly varied among honeys. Neither botanical source nor geographical origin of honeys affected the level of GOX suggesting that some other factors such as honeybee nutrition and/or genetic/epigenetic factors may take part in the observed variation. A strong correlation was found between the content of GOX and the level of generated H2O2 in honeys except honeydew honeys. Total antibacterial activity of most honey samples against Pseudomonas aeruginosa isolate significantly correlated with the H2O2 content. These results demonstrate that the level of GOX can significantly affect the total antibacterial activity of honey. They also support an idea that breeding of novel honeybee lines expressing higher amounts of GOX could help to increase the antibacterial efficacy of the hypopharyngeal gland secretion that could have positive influence on a resistance of colonies against bacterial pathogens. 相似文献
82.
Vidović Kristijan Hočevar Samo Menart Eva Drventić Ivana Grgić Irena Kroflič Ana 《Environmental science and pollution research international》2022,29(31):46405-46437
Environmental Science and Pollution Research - Atmospheric gases and particulate matter (PM) in contact with the material’s surface lead to chemical and physical changes, which in most cases... 相似文献
83.
Chicken eggs from five different production types (conventional, omega-3 enriched, free range, organic and free run) were collected, when available, from three regions (west, central and east) of Canada to determine persistent organic pollutant (POP) concentrations. Total polychlorinated biphenyl (PCB) concentrations (∑37 congeners) in yolks from the eggs ranged from 0.162 ng g−1 lipid to 24.8 ng g−1 lipid (median 1.25 ng g−1 lipid) while the concentration of the sum of the 6 indicator PCBs ranged from 0.100 ng g−1 lipid to 9.33 ng g−1 lipid (median 0.495 ng g−1 lipid). Total polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations ranged from 2.37 pg g−1 lipid to 382 pg g−1 lipid (median 9.53 pg g−1 lipid). The 2005 WHO toxic equivalency (TEQ) ranged from 0.089 pg TEQPCDD/F+dioxin-like[DL]-PCB g−1 lipid to 12.8 pg TEQPCDD/F+DL-PCB g−1 lipid (median 0.342 pg TEQPCDD/F+DL-PCB g−1 lipid). PCB and PCDD/F concentrations were significantly different (p < 0.001) in egg yolks from different regions of collection. In contrast to observations in Europe, PCB and PCDD/F concentrations in Canadian egg yolks were not impacted solely by the production type (e.g., conventional, free range, organic, etc.) used to maintain the laying chickens. Additionally, only one Canadian free range yolk from western Canada (12.8 pg TEQPCDD/F+DL-PCB g−1 lipid) exceeded the European toxic equivalent concentration limits for eggs (5 pg TEQPCDD/F+DL-PCB g−1 lipid). This differs from observations in Europe where free range/home produced eggs frequently have higher POP concentrations than eggs from other production types. Median PCB dietary intake estimates based on consumption of eggs were less than 10 ng d−1 while median PCDD/F intakes were less than 45 pg d−1. 相似文献