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81.
Prof. Christchellyn Klegin Prof. Dr. Eduardo Miranda Ethur Bárbara Buhl Ana Caroline Giacomin Prof. Dr. Juçara Bordin Prof. Dr. Neusa Fernandes de Moura Matheus Henrique Oliveira de Sousa 《化学与生物多样性》2023,20(6):e202300253
The present study aimed to examine the phenolic content and evaluate the antimicrobial and antioxidant potential of ethanol extracts from the moss species Phyllogonium viride Brid. on the pathogenic bacteria Salmonella enterica serovar enteritidis, Staphylococcus aureus, Listeria monocytogenes and Escherichia coli, and the pathogenic fungi Candida albicans and Cryptococcus neoformans. The antimicrobial activity was determined from Minimum Inhibitory Concentration (MIC) Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC). Antioxidant activity was determined by the DPPH method. Folin-Denis reagent was used for the content of total phenolics and flavonoids and HPLC-DAD for identification of phenolic compounds. The results showed that bacteriostatic and bactericidal activities occurred at concentrations ranging from 9.76 μg/mL–78.13 μg/mL among all evaluated microorganisms. These values, considering the criteria used, suggest the P. viride extract as a potent antimicrobial. For antioxidant activity, P. viride extract was considered weak. Analysis of the phenolic content showed a wide range of compounds, with Kaempferol (0.41 mg/g) being the major compound, followed by t-cinnamic acid and caffeic acid (0.17 mg/g). Although P. viride is a species of moss not yet referenced in scientific publications of biotechnological interest, it has shown promising potential for further studies and possible application as an antimicrobial of natural origin. 相似文献
82.
Sven Rossel Patricia Kaiser Maya Bode-Dalby Jasmin Renz Silke Laakmann Holger Auel Wilhelm Hagen Pedro Martínez Arbizu Janna Peters 《Molecular ecology resources》2023,23(2):382-395
Species identification is pivotal in biodiversity assessments and proteomic fingerprinting by MALDI-TOF mass spectrometry has already been shown to reliably identify calanoid copepods to species level. However, MALDI-TOF data may contain more information beyond mere species identification. In this study, we investigated different ontogenetic stages (copepodids C1–C6 females) of three co-occurring Calanus species from the Arctic Fram Strait, which cannot be identified to species level based on morphological characters alone. Differentiation of the three species based on mass spectrometry data was without any error. In addition, a clear stage-specific signal was detected in all species, supported by clustering approaches as well as machine learning using Random Forest. More complex mass spectra in later ontogenetic stages as well as relative intensities of certain mass peaks were found as the main drivers of stage distinction in these species. Through a dilution series, we were able to show that this did not result from the higher amount of biomass that was used in tissue processing of the larger stages. Finally, the data were tested in a simulation for application in a real biodiversity assessment by using Random Forest for stage classification of specimens absent from the training data. This resulted in a successful stage-identification rate of almost 90%, making proteomic fingerprinting a promising tool to investigate polewards shifts of Atlantic Calanus species and, in general, to assess stage compositions in biodiversity assessments of Calanoida, which can be notoriously difficult using conventional identification methods. 相似文献
83.
COPII coat subunit interactions: Sec24p and Sec23p bind to adjacent regions of Sec16p. 总被引:9,自引:2,他引:7 下载免费PDF全文
Formation of COPII-coated vesicles at the endoplasmic reticulum (ER) requires assembly onto the membrane of five cytosolic coat proteins, Sec23p, Sec24p, Sec13p, Sec31p, and Sar1p. A sixth vesicle coat component, Sec16p, is tightly associated with the ER membrane and has been proposed to act as a scaffold for membrane association of the soluble coat proteins. We previously showed that Sec23p binds to the C-terminal region of Sec16p. Here we use two-hybrid and coprecipitation assays to demonstrate that the essential COPII protein Sec24p binds to the central region of Sec16p. In vitro reconstitution of binding with purified recombinant proteins demonstrates that the interaction of Sec24p with the central domain of Sec16p does not depend on the presence of Sec23p. However, Sec23p facilitates binding of Sec24p to Sec16p, and the three proteins can form a ternary complex in vitro. Truncations of Sec24p demonstrate that the N-terminal and C-terminal regions of Sec24p display different binding specificities. The C terminus binds to the central domain of Sec16p, whereas the N terminus of Sec24p binds to both the central domain of Sec16p and to Sec23p. These findings define binding to Sec16p as a new function for Sec24p and support the idea that Sec16p organizes assembly of the COPII coat. 相似文献
84.
In onion ( Allium cepa L.) postponement of sprouting is necessary to achieve long term storage. We studied the factors determining sprouting during dry storage at 16°C. The period to visible sprouting depends on the length of the dormancy period, if present, and on the growth rate of the sprout. In the three cultivars tested, sprouts were initiated within 2 weeks after harvest indicating the absence of a real dormancy period. Sprout length increased linearly during storage. The mitotic activity of the apex decreased before harvest, was low at the transition from scale to leaf formation, and increased again when the sprout was initiated. From a few weeks before harvest, the initially high fructan content of the scales decreased, leading to a large increase in fructose. The sprout always contained enough carbohydrates for growth (between 50 and 60 mg g−1 dry weight, of which 30% was fructan). The activity of sucrose synthase (EC 2.4.1.13) increased as the sprout grew, indicating an increase in sink strength. Invertase (EC 3.2.1.26) was absent in all bulb organs, during the various developmental stages. Although carbohydrates and enzymes were available for fast sprouting, sprout growth was still linear instead of exponential during dry storage at temperatures favorable for growth (16°C). The relative importance of factors determining sprouting are discussed. 相似文献
85.
During a transition from aerobic to largely anaerobic conditionslight-saturated carbon assimilation of intact chloroplasts wasnot decreased although both the transthylakoid proton gradientand ATP levels declined. After a dark period under anaerobiosis,illumination failed to initiate carbon assimilation. ATP increasedonly transiently in the light and then returned to the darklevel. Under such conditions, the addition of electron acceptorssuch as oxygen, oxalacetate or nitrite resulted in the increaseof ATP levels and carbon assimilation was initiated. Assimilationcontinued under anaerobiosis in the presence of reduced protongradients and reduced ATP levels after electron acceptors addedin addition to bicarbonate were reduced. Cyclic electron transport was inhibited when anaerobiosis didnot permit linear electron transport. It was induced in thissituation by micromolar concentrations of oxygen or when, underanaerobiosis, DCMU decreased PSII activity. Oxygen inhibitedcyclic electron transport by draining electrons from the cyclicpathway only when electron donation from PSII was weak. Theobservations give evidence of the delicate redox balance requiredfor cyclic electron transport. Since H+/e=3 in linear electron transport, the observationsof effective carbon reduction under a decreased transthylakoidproton gradient and decreased levels of ATP are incompatiblewith H+/ATP=2 or 3. They are compatible with H+/ATP=4. (Received May 1, 1995; Accepted October 3, 1995) 相似文献
86.
Caroline E. G. Tutin Richard J. Parnell Lee J. T. White Michel Fernandez 《International journal of primatology》1995,16(1):53-76
We analyzed data from 373 fresh nest-sites (containing 2435 nests) of lowland gorillas (Gorilla g. gorilla)during a 4-year period in the Lopé Reserve, Gabon, to determine whether the observed variability in nest building was due to environmental influences. We recognized and defined seven types of nest in terms of the degree of construction and the raw materials used. Overall, nests built on the ground from herbaceous plants are the most common type (40%), followed by tree nests (35%). Frequencies of the different nest-types vary significantly between eight habitat-types. In habitat-types with high densities of understory herbs, ground nests predominated, but when herbs were rare, the majority of nests were in trees. A general preference for sleeping in herbaceous ground nests is indicated since trees are abundant in all habitat-types, except savanna. The frequency of nesting in trees shows a significant positive correlation with rainfall, but effects of climate are confounded by seasonal variation in use of different habitat-types. When elephants were attracted to the same localized food sources as gorillas, many tree nests were built even when herbs were available. We conclude that different nest-types reflect a variety of solutions to maximize comfort, depending on available raw materials and the probability of rainfall or disturbance by elephants or both factors. Nests are a powerful tool for population censuses and demographic studies of great apes, but problems exist in interpreting data on lowland gorilla nests. Results from this analysis show that only a third of nest-sites accurately reflects group size (of weaned individuals) and that 26% of all gorilla nest-sites could be mistaken for those of chimpanzees, as all nests, or all those visible from a transect, were in trees. Gorilla nests at Lopé were nonrandomly distributed with respect to habitat-types, and nest construction varied seasonally, thereby introducing sources of bias to transect nest counts. We discuss these problems and ones related to assessing the decay rate of nest-sites and make recommendations relevant to census work. 相似文献
87.
Caroline E. G. Tutin Richard J. Parnell Lee J. T. White Michel Fernandez 《International journal of primatology》1995,16(2):53-76
We analyzed data from 373 fresh nest-sites (containing 2435 nests) of lowland gorillas (Gorilla g. gorilla)during a 4-year period in the Lopé Reserve, Gabon, to determine whether the observed variability in nest building was due
to environmental influences. We recognized and defined seven types of nest in terms of the degree of construction and the
raw materials used. Overall, nests built on the ground from herbaceous plants are the most common type (40%), followed by
tree nests (35%). Frequencies of the different nest-types vary significantly between eight habitat-types. In habitat-types
with high densities of understory herbs, ground nests predominated, but when herbs were rare, the majority of nests were in
trees. A general preference for sleeping in herbaceous ground nests is indicated since trees are abundant in all habitat-types,
except savanna. The frequency of nesting in trees shows a significant positive correlation with rainfall, but effects of climate
are confounded by seasonal variation in use of different habitat-types. When elephants were attracted to the same localized
food sources as gorillas, many tree nests were built even when herbs were available. We conclude that different nest-types
reflect a variety of solutions to maximize comfort, depending on available raw materials and the probability of rainfall or
disturbance by elephants or both factors. Nests are a powerful tool for population censuses and demographic studies of great
apes, but problems exist in interpreting data on lowland gorilla nests. Results from this analysis show that only a third
of nest-sites accurately reflects group size (of weaned individuals) and that 26% of all gorilla nest-sites could be mistaken
for those of chimpanzees, as all nests, or all those visible from a transect, were in trees. Gorilla nests at Lopé were nonrandomly
distributed with respect to habitat-types, and nest construction varied seasonally, thereby introducing sources of bias to
transect nest counts. We discuss these problems and ones related to assessing the decay rate of nest-sites and make recommendations
relevant to census work. 相似文献
88.
89.
Dirofilaria immitis: heartworm infection alters pulmonary artery endothelial cell behavior 总被引:1,自引:0,他引:1
Mupanomunda Maria; Williams Jeffrey F.; Mackenzie Charles D.; Kaiser Lana 《Journal of applied physiology》1997,82(2):389-398
Mupanomunda, Maria, Jeffrey F. Williams, Charles D. Mackenzie, and Lana Kaiser. Dirofilaria immitis:heartworm infection alters pulmonary artery endothelial cell behavior.J. Appl. Physiol. 82(2): 389-398, 1997.Thepathogenesis of filariasis has generally been attributed to eitherphysical presence of the adult parasites or the host's immune responseto the parasites. However, the spectrum of filariasis cannot beentirely explained by these causes, and other mechanisms must beoperative. It is now evident that factors released by filarialparasites likely contribute to the pathogenesis of filarial diseases.Adult heartworms (Dirofilaria immitis) reside in the rightheart and pulmonary artery, so the pulmonary artery should be exposedto the highest concentration of filarial factors. We tested thehypothesis that endothelium-dependent relaxation is altered in the invitro pulmonary artery from heartworm-infected dogs. Relaxationresponses to endothelium-dependent vasodilators (methacholine,bradykinin, substance P, and A-23187) and the non-endothelium-dependent vasodilator nitroglycerin and contractile responses were measured inrings of pulmonary artery from control and heartworm-infected dogs.Endothelium-dependent relaxation was assessed in the presence andabsence of inhibitors of nitric oxide synthase, cyclooxygenase, andguanylate cyclase. Responses to methacholine, substance P, and A-23187,but not to bradykinin, nitroglycerin, norepinephrine, or KCl, weredepressed in pulmonary artery from heartworm-infected dogs whencompared with control, suggesting that changes in endothelial cell andnot vascular smooth muscle behavior are involved in altered relaxation.The mechanism of endothelium-dependent relaxation in control pulmonaryartery appears to involve nitric oxide in the case of methacholine andboth nitric oxide and a cyclooxygenase product in the case ofbradykinin and A-23187. The mechanism of endothelium-dependentrelaxation in pulmonary artery from heartworm-infected dogs was notclearly elucidated. These data provide no evidence that heartworminfection globally influences either endothelial cell receptor functionor the vascular smooth muscle guanylate cyclase guanosine 3,5-cyclicmonophosphate system, making it likely that changes in intracellularsignaling are primarily responsible for the observed alteration ofendothelium-mediated relaxation. Alteration of endothelial cellfunction by filarial parasites may be an important component inthe pathology associated with filariasis. 相似文献
90.
Proteolytic activity of proteasome on myofibrillar structures 总被引:5,自引:0,他引:5
Richard G. Taylor Caroline Tassy Mariele Briand Nathalie Robert Yves Briand Ahmed Ouali 《Molecular biology reports》1995,21(1):71-73
The physiologic function of proteasome remains unclear. Evidence suggests a role in degradation of ubiquitin-protein conjugates, MHC antigen presentation, and some specificity of substrate within certain cell types. To explore further the properties of proteasome we have examined its effect on a well defined structure, the myofibril. We find that despite its large size (20S) proteasome is able to degrade myofibrils and intact, permeabilized muscle fibrils. The proteins degraded showed some specificity because actin, myosin and desmin were degraded faster than -actinin, troponin T and tropomyosin. Changes in ultrastructure were slow and included a general loss of structure with Z and I bands effected before the M band and costameres. 相似文献