Chromosome Tips Damaged in Anaphase Inhibit Cytokinesis

Genome maintenance is ensured by a variety of biochemical sensors and pathways that repair accumulated damage. During mitosis, the mechanisms that sense and resolve DNA damage remain elusive. Studies have demonstrated that damage accumulated on lagging chromosomes can activate the spindle assembly checkpoint. However, there is little known regarding damage to DNA after anaphase onset. In this study, we demonstrate that laser-induced damage to chromosome tips (presumptive telomeres) in anaphase of Potorous tridactylis cells (PtK2) inhibits cytokinesis. In contrast, equivalent irradiation of non-telomeric chromosome regions or control irradiations in either the adjacent cytoplasm or adjacent to chromosome tips near the spindle midzone during anaphase caused no change in the eventual completion of cytokinesis. Damage to only one chromosome tip caused either complete absence of furrow formation, a prolonged delay in furrow formation, or furrow regression. When multiple chromosome tips were irradiated in the same cell, the cytokinesis defects increased, suggesting a potential dose-dependent mechanism. These results suggest a mechanism in which dysfunctional telomeres inhibit mitotic exit

Przeciwdrobnoustrojowe i przeciwwirusowe właściwości różnych typów propolisu

Propolis is produced by bees; it is a viscous, resinous substance mainly derived from trees, shrubs, and flower buds, enriched in wax, essential oils, pollen, and bee saliva. The composition of propolis varies widely depending on the region of origin and vegetation that occurs in the area, the climate, and the season in which it is produced. So far, more than 400 substances have been identified in propolis and among them are phenols, flavonoids, phenolic acids and their esters and flavones. Propolis is divided into several types; the most common types are poplar, European, Brazilian, and pacific propolis. Antimicrobial, antifungal, and antiviral effects of propolis have been demonstrated. Propolis inhibits Gram-positive bacteria and, to a lesser extent, Gram-negative bacteria. Propolis also inhibits the growth of mold (Aspergillus and Penicillium) and yeast (Candida). The antiviral activity of propolis against poliovirus, influenza A and B viruses, reoviruses, and HIV has been demonstrated.Propolis wytwarzany jest przez pszczoły w formie mazi głównie z substancji żywicznych pochodzących z drzew, krzewów oraz pąków kwiatowych, wzbogacony w wosk, olejki eteryczne, pyłek kwiatowy oraz ślinę pszczół (Apis mellifera). Skład propolisu jest bardzo zróżnicowany w zależności od regionu pochodzenia i roślinności występującej na danym terenie, klimatu oraz pory roku, w której jest produkowany. Do tej pory w składzie chemicznym propolisów zidentyfikowano ponad 400 substancji: fenole, flawonoidy, kwasy fenolowe i ich estry, flawony, dihydroksyflawony, chalkony oraz glicerydy fenolowe. Propolis podzielono na kilka typów. Najczęściej spotykane typy to propolis: topolowy, europejski, brazylijski i pacyficzny. Wykazano także jego przeciwbakteryjne, przeciwgrzybicze oraz przeciwwirusowe działanie, zwłaszcza etanolowych ekstraktów. Propolis działa hamująco na bakterie Gram-dodatnie, a w mniejszym stopniu na bakterie Gram-ujemne, hamuje również rozwój pleśni (Aspergillus i Penicillium) oraz drożdży (Candida). Dowiedziono także, że propolis ma właściwości przeciwwirusowe (względem wirusa polio, wirusa grypy typu A i B, reowirusów, a także wirusa HIV)

Skład chemiczny i aktywność przeciwdrobnoustrojowa olejku eterycznego petitgrain (Citrus aurantium L. var. amara)

Introduction: Due to its low cost and easy availability on the market, the petitgrain oil is commonly used in food, cosmetics, and aromatherapy. Objective: The examination of chemical composition and antibacterial activity of commercial petitgrain oil. Methods: Identification of chemical components of the petitgrain oil was performed by gas chromatography (GC). The minimum inhibitory concentrations (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC) were determined using macrodilution method for the reference strains of bacteria and fungi. Results: Twenty components were identified. The petitgrain oil contained mostly oxygenated monoterpene hydrocarbons (98.01%), and the main components included linalyl acetate (48.06%) and linalool (26.88%). The MIC/MBC of the petitgrain oil for bacteria was in the range of 0.63–5.0/1.25–5.0 mg/ml and for fungi in the range of 1.25–40/5.0–80 mg/ml. Conclusion: The petitgrain oil had higher antibacterial activity than antifungal activity. Bacillus subtilis among the tested bacteria and Aspergillus niger and Penicillium expansum among the fungi were found to be highly inhibited by the petitgrain oil.Wstęp: Olejek eteryczny petitgrain ze względu na niewielki koszt i dostępność na rynku jest często stosowany w produkcji żywności, kosmetyków i aromaterapii. Cel: Zbadano skład chemiczny i aktywność przeciwdrobnoustrojową handlowego olejku petitgrain. Metodyka: Identyfikację chemicznych składników olejku petitgrain wykonano przy użyciu chromatografii gazowej (GC). Minimalne stężenia hamujące (mic) oraz minimalne stężenia bakteriobójcze/grzybobójcze (MBC/MFC) zostały oznaczone metodą makrorozcieńczeń wobec referencyjnych szczepów bakterii i grzybów. Wyniki: Zidentyfikowano dwadzieścia kompotentów. Olejek petitgrain zawierał najwięcej utlenionych węglowodorów monoterpenowych (98.01%), a głównymi składnikami były: octan linalilu (48,06%) i linalool (26,88%). MIC/MBC olejku petitgrain wobec bakterii były w granicach 0,63–5,0/1,25−5,0 mg/ml, a wobec grzybów były w zakresie 1,25–40/5,0–80 mg/ml. Wnioski: Olejek petitgrain miał większą aktywność przeciwbakteryjną niż przeciwgrzybiczną. Spośród badanych bakterii Bacillus subtilis, a spośród grzybów Aspergillus niger i Penicillium expansum były najsilniej hamowane przez olejek petitgrain

The aspects of microbial biomass use in the utilization of selected waste from the agro-food industry

Cellular biomass of microorganisms can be effectively used in the treatment of waste from various branches of the agro-food industry. Urbanization processes and economic development, which have been intensifying in recent decades, lead to the degradation of the natural environment. In the first half of the 20th century, problems related to waste management were not as serious and challenging as they are today. The present situation forces the use of modern technologies and the creation of innovative solutions for environmental protection. Waste of industrial origin are difficult to recycle and require a high financial outlay, while the organic waste of animal and plant origins, such as potato wastewater, whey, lignin, and cellulose, is dominant. In this article, we describe the possibilities of using microorganisms for the utilization of various waste products. A solution to reduce the costs of waste disposal is the use of yeast biomass. Management of waste products using yeast biomass has made it possible to generate new metabolites, such as β-glucans, vitamins, carotenoids, and enzymes, which have a wide range of industrial applications. Exploration and discovery of new areas of applications of yeast, fungal, and bacteria cells can lead to an increase in their effective use in many fields of biotechnology

Zastosowanie metody termograficznej w mikrobiologii

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Comparison of the Chemical Composition and Antioxidant Properties of Propolis from Urban Apiaries

Bee products from urban apiaries are increasingly used. They are mainly used to promote local apiaries and cities in which they are located. The aim of the study was to compare the chemical composition and antioxidant activity of propolis from 6 Polish apiaries located in cities (Legionowo, Torun, Cracow, Warsaw, Katowice, Lodz). The chemical composition was analyzed using liquid chromatography (HPLC-DAD) and the analysis of antioxidant activity by scavenging free radicals (ABTS and DPPH) and FRAP. The obtained results showed the presence of 24 phenolic compounds in propolis extracts. The tested samples showed differentiation in terms of the content of individual chemical components, however, cinnamic acid and its derivatives were dominant. High antioxidant activity of the tested extracts was demonstrated (ABTS was in the range of 16.80–51.53 mg Te/mL, DPPH was in the range of 7.54–22.13 mg Te/mL, while FRAP reduction was in the range of 10.93–29.55 mg Te/mL). The obtained results compared with literature data on propolis from agricultural areas allow to conclude that propolis samples from both Poland types of areas are similar and can be classified as poplar propolis