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1.
The objective of the present study was that of verifying a possible synergistic antibacterial effect between Pelargonium graveolens [Lis-Balchin, M., Deans, S.G., Hart, S., 1996. Bioactive Geranium oils from different commercial sources. J. Essential Oil Res. 8, 281-290.] essential oil (and its main components) and Norfloxacin antibiotic. As a first step growth inhibition by some types of essential oils was assessed in five microbial species. The antimicrobial effects of P. graveolens oil, as well as those of its components, were evaluated by means of the agar dilution method (ADM) against Bacillus cereus ATCC 11778, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 35218, Staphylococcus aureus ATCC 6538 and S. aureus ATCC 29213. The results obtained highlighted the occurrence of a pronounced synergism between P. graveolens essential oil and Norfloxacin against three of the five bacterial species under study with a FIC index in the 0.37-0.50 range. Such antibacterial effects were also shown to increase, although to a lesser extent, when Norfloxacin was given with the main components of P. graveolens essential oil. SIGNIFICANCE AND IMPACT OF THE STUDY: The combination of Norfloxacin with either P. graveolens essential oil, or with some of the main components of this latter, in the treatment of infections caused by some bacterial species is likely to reduce the minimum effective dose of Norfloxacin thus minimizing the side effects of the antibiotic.  相似文献   

2.
The occurrence of the fish Cephalopholis taeniops (Serranidae: Epinephelinae) has been recorded for the first time in the Canary Islands (eastern subtropical Atlantic). Repeated observations of adult stages of the species (??30?cm total length) inside oil platforms coming from the Gulf of Guinea greatly suggest an introduction related to the transport of ballast water in these structures, and show their importance in the dispersal of adult stages of large-sized species of littoral fish. Oil platforms constitute one special case in the introduction of marine species in the context of ballast water transport. This poorly known phenomenon may greatly favour marine species invasion, and might have significant repercussions in many regions -especially in the current climate change context- as well as explaining some surprising cases of occurrence of expatriated adult individuals of certain species.  相似文献   

3.
李博园  王娟  高静  陈旋勐  陈莹 《广西植物》2020,40(4):471-481
为探明杭白芷(Angelica dahurica var.formosana)根中分泌道发生方式、分布及其挥发油转运积累特征,该研究利用光镜及透射电子显微镜技术观察分泌道发生过程及挥发油转运特征,结合组织化学定位确定挥发油的主要积累部位。结果表明:杭白芷根中分泌道由中柱鞘细胞最先发生,次生结构中分泌道主要分布在韧皮部和皮层中;挥发油的合成不仅与分泌细胞中质体及细胞质有关,而且还与周围细胞关系密切;分泌细胞内高尔基体和内质网丰富,可能先通过形成小泡参与转运,再经由细胞壁向腔道内转移;相邻分泌细胞靠近角隅处的细胞壁分泌活动活跃,腔道内积累大量电子致密物质;成熟分泌道中分泌细胞及其腔道内积累大量油滴,因此挥发油主要积累场所为分泌细胞及其腔道。该研究明确了杭白芷根中分泌道的发生方式、分布及其挥发油积累部位,揭示了分泌道发育过程中挥发油的转运积累特征,为进一步阐明分泌组织生长发育与有效成分积累关系提供了理论依据。  相似文献   

4.
5.
Interaction networks within biotic communities can be dramatically altered by anthropogenic habitat modification. Ants, an important ecological group, often interact competitively to form mosaic‐like patterns in disturbed plantation habitats, in which dominant species form mutually exclusive territories. However, the existence of these ant mosaics in pristine forests is contentious. Here we assess the relative strengths of ant competitive interactions in oil palm plantation and primary rain forest in Sabah, Malaysia, using null models of species co‐occurrence. We use two metrics: the C‐score, which measures mean degree of overall co‐occurrence, and a novel metric, the Cvar‐score, which measures the variance in degree of co‐occurrence. We also investigate the role of nest sites by collecting ants from canopy and leaf litter microhabitats, and from epiphytic ferns, an important nest site for canopy ants. Furthermore, we assess whether non‐native species, which were widespread in oil palm plantation (61 occurrences vs five in rain forest) are important in driving the formation of ant mosaics. We found no evidence for ant mosaics in any primary forest microhabitat. In oil palm plantation, segregation between species was pronounced in epiphytes, weak in the rest of the canopy and absent in leaf litter communities. Intriguingly, exclusion of non‐native ant species from analyses increased the degree of negative species co‐occurrence in all three microhabitats, with species segregation in the oil palm canopy becoming statistically significant. Our results suggest that invasion of plantation habitats by non‐native species does not drive increased species segregation in ant communities. Rather, high degrees of species segregation might relate to changes in the importance of canopy nest sites, with colonies competing more strongly for these in plantations. In primary forests, weaker nest‐site limitation and the highly complex, more vertically stratified, non‐uniform canopy could lead to random co‐occurrence between ant species at the scales studied here.  相似文献   

6.
Leaf exudates from individuals of 29 species included in Aloe Section Pachydendron have been separated by TLC and HPLC to reveal their phenolic components. All the zones are described by their chromatographic behaviour and UV absorption properties, but not all can be identified as known compounds so are distinguished by an arbitrary code. Section Pachydendron has been shown to be chemically heterogeneous akhough there are some correlations between species said to be taxonomically related. Without attaching taxonomic significance four chemical groupings can be discerned: (1) species in which chromones are prominent; (2) species in which andirone and anthraquinone glycosides are prominent; (3) species containing mainly purple-staining phenolic compounds; and (4) species with few leaf exudate phenolic compounds. This survey emphasizes the uncertain taxonomy of the Section and the need for more extensive collection and analysis.  相似文献   

7.
The composition of the essential oil of A. rehan has been studied. A total of 22 components were identified, the major components being davanone and camphor, and the occurrence of eudalene is noted for the first time. The characteristic blue colour of the oil is due to chamazulene.  相似文献   

8.
The aim of this study was to evaluate the occurrence of yeast populations during different olive oil extraction processes, carried out in three consecutive years in Tuscany (Italy), by analysing crushed pastes, kneaded pastes, oil from decanter and pomaces. The results showed yeast concentrations ranging between 103 and 105 CFU/g or per mL. Seventeen dominant yeast species were identified by random amplified polymorphic DNA with primer M13 and their identification was confirmed by restriction fragments length polymorphism of ribosomal internal transcribed spacer and sequencing rRNA genes. The isolation frequencies of each species in the collected samples pointed out that the occurrence of the various yeast species in olive oil extraction process was dependent not only on the yeasts contaminating the olives but also on the yeasts colonizing the plant for oil extraction. In fact, eleven dominant yeast species were detected from the washed olives, but only three of them were also found in oil samples at significant isolation frequency. On the contrary, the most abundant species in oil samples, Yamadazyma terventina, did not occur in washed olive samples. These findings suggest a phenomenon of contamination of the plant for oil extraction that selects some yeast species that could affect the quality of olive oil.  相似文献   

9.
Time-series data collected over a four-year period were used to characterize patterns of abundance for pelagic fishes in the northern Gulf of Mexico (GoM) before (2007–2009) and after (2010) the Deepwater Horizon oil spill. Four numerically dominant pelagic species (blackfin tuna, blue marlin, dolphinfish, and sailfish) were included in our assessment, and larval density of each species was lower in 2010 than any of the three years prior to the oil spill, although larval abundance in 2010 was often statistically similar to other years surveyed. To assess potential overlap between suitable habitat of pelagic fish larvae and surface oil, generalized additive models (GAMs) were developed to evaluate the influence of ocean conditions on the abundance of larvae from 2007–2009. Explanatory variables from GAMs were then linked to environmental data from 2010 to predict the probability of occurrence for each species. The spatial extent of surface oil overlapped with early life habitat of each species, possibly indicating that the availability of high quality habitat was affected by the DH oil spill. Shifts in the distribution of spawning adults is another factor known to influence the abundance of larvae, and the spatial occurrence of a model pelagic predator (blue marlin) was characterized over the same four-year period using electronic tags. The spatial extent of oil coincided with areas used by adult blue marlin from 2007–2009, and the occurrence of blue marlin in areas impacted by the DH oil spill was lower in 2010 relative to pre-spill years.  相似文献   

10.
1. Gram-positive bacteria out of the families of Streptococcaceae, Lactobacillaceae, Micrococcaceae and Bacillaceae were investigated with respect to the occurrence and the concentration of phosphoglycolipids. 2. Phosphatidylglycolipids occur exclusively in group D Streptococci and in Streptococcus hemolyticus D-58. Phosphatidyl-alpha-kojibiosyldiacylglycerol, the prevalent species, accounts for up to 28% of the polar lipids. The related glycerophospho-phosphatidyl-alpha-kojibiosyldiacylglycerol is restricted to Streptococcus faecalis. 3. Glycerophosphoglycolipids, usually minor components, comprise thirteen compounds most of which have so far not been described. Except Micrococcus lysodeikticus all examined bacteria contained one or more glycerophosphoglycolipids. Their occurrence parallels, therefore, that of lipoteichoic acids, which supports the hypothesis of a metabolic relationship between these two membrane components.  相似文献   

11.
The chemical components of different genera and species of Taxaceae have been analyzed in order to provide data for discussion of the systematic position of this family. A characteristic component tsugalacton (or tsugaresinol) from trunk of Pseudotaxus chienii (Cheng) Cheng has been reported in our previous paper. The present paper deals with our preliminary study on essential oil composition of leaves in the same species. Thirt-eight components have been isolated and 33 of them have been identified. Three of them, limonene, α-pinene, and δ-3-carene, are the main ones, with their contents being more than 1/3 in the total essential oil. This characteristic of the essential oil composition from leaves of Pseu- dotaxus chienii resembles to that of Torreya grandis cv. ‘Merrillii’.  相似文献   

12.
Analysis by GC and GC/MS of the essential oil obtained from above-ground parts of Micromeria dalmatica Benth. allowed the identification of 116 components, comprising 93.6% of the total oil composition. The major compounds are 3-oxygenated p-menthane monoterpenes and were identified as pulegone (29.6%), menthone (11.7%), and piperitenone (10.8%). The chemical composition of this and additional 30 oils obtained from selected Micromeria Benth. taxa were compared by using multivariate statistical analysis (agglomerative hierarchical cluster analysis and principal component analysis (PCA)). The results of statistical analyses, as well as the domination of different concurrent p-menthane-skeleton-type monoterpene biosynthetical sub-branches in the compared M. dalmatica samples, implied the occurrence of at least two different chemotypes of the mentioned species.  相似文献   

13.
Aim This study investigates changes in bird communities between 1998 and 2008 in four savanna sites in Swaziland and the extent to which shrub encroachment is responsible for these changes. Location Swaziland, southern Africa. Methods Generalized estimated equations were used to estimate changes in bird species occurrence between 1998 and 2008. Remote sensing of aerial photographs/satellite images was used to assess vegetation changes during the same period. We assessed the role of shrub encroachment for bird communities by testing the relationship between change in species occurrence and species habitat using a general linear model. We also estimated species richness, colonization and extinction and used general linear models to test the effects of vegetation changes on these parameters. Results More than half of the bird species showed a significant change in occurrence between 1998 and 2008: 32 species increased and 29 decreased. Change in species occurrence was significantly explained by species habitat. Species significantly increasing were mainly associated with wooded savanna, whereas species significantly decreasing were mainly associated with open savanna. Species richness decreased significantly, and this decrease was significantly explained by shrub cover increase at the plot scale (from 24% to 44% on average). Extinction at the plot scale was significantly influenced by the loss of grass cover, while colonization at the plot scale was influenced by tree cover increase. Main conclusions This study represents the first evidence of temporal changes in bird communities owing to shrub encroachment in southern Africa. Despite its short time frame (10 years), this study shows dramatic changes in both vegetation structure and bird community composition. This confirms the general concern for southern African bird species associated with open savanna if current trends continue.  相似文献   

14.
In plants, green non-foliar organs are able to perform photosynthesis just as leaves do, and the seed-enclosing pod acts as an essential photosynthetic organ in legume and Brassica species. To date, the contribution of pod photosynthesis to seed yield and related components still remains largely unexplored, and in Arabidopsis thaliana, the photosynthetic activity of the silique (pod) is unknown. In this study, an Arabidopsis glk1/glk2 mutant defective in both leaf and silique photosynthesis was used to create tissue-specific functional complementation lines. These lines were used to analyze the contribution of silique wall photosynthesis to seed yield and related traits, and to permit the comparison of this contribution with that of leaf photosynthesis. Our results showed that, together with leaves, the photosynthetic assimilation of the silique wall greatly contributed to total seed yield per plant. As for individual components of yield traits, leaf photosynthesis alone contributed to the seed number per silique and silique length, while silique wall photosynthesis alone contributed to thousand-seed weight. In addition, enhancing the photosynthetic capacity of the silique wall by overexpressing the photosynthesis-related RCA gene in this tissue resulted in significantly increased seed weight and oil content in the wild-type (WT) background. These results reveal that silique wall photosynthesis plays an important role in seed-related traits, and that enhancing silique photosynthesis in WT plants can further improve seed yield-related traits and oil production. This finding may have significant implications for improving the seed yield and oil production of oilseed crops and other species with pod-like organs.  相似文献   

15.
This review sought to describe the role played by some components of the microbiota of extra virgin olive oil (EVOO), particularly yeasts, in structuring the physicochemical and sensorial quality of freshly produced olive oil. Yeasts can survive during the entire storage period of the product. To date, approximately 25 yeast species isolated from oil produced in more than six countries have been identified, eight of which are classified as new species. Some yeast species improve the health qualities of oil, whereas many others improve the chemical composition and sensory characteristics based on β-glucosidase and esterase enzymes, which are involved in the hydrolysis of the bitter glucoside known as oleuropein. However, some species, which are typically favoured by the high water content in the oily matrix, such as lipase-producing yeasts, can worsen the initial chemical characteristics of EVOO oil during storage. Some physical treatments that are compatible with the EVOO production specification affect the biotic component of the oil by reducing the concentration of yeasts. The possibility of minimizing the invasive action on the biotic component of the oil by appropriately selecting the physical treatment for each oil is discussed.  相似文献   

16.
Although there is agreement on the fact that Sarcina lutea strain FD-533 has branched C-29 monoalkenes as major hydrocarbon components, there is disagreement in the literature as to the nature of the branching. This has been resolved by analyses of the fatty acids produced by permanganate-periodate treatment of each of the resolvable hydrocarbon fractions making up the C-29 complex. The three major components are identified as doubly branched, Delta(13) species with two iso terminations, one iso and one anteiso termination, and two anteiso terminations.  相似文献   

17.
1. The occurrence and gel electrophoretic properties of low molecular weight RNA components (LMW RNA) have been studied in species at different taxonomic levels. The LMW RNA components apart from tRNA, 5S RNA and 5.5S RNA are called LMW*RNA. 2. The major components of LMW*RNA in mammalian cells are L, A, C and D, accounting for 0.1-0.7% of cellular RNA. The gel electrophoretic migration of components L, C, and D is similar in different mammals but the migration of component A shows differences. 3. Amphibia, reptiles and birds contain L, A, C and D in about the same amounts as mammals but slight differences in migration are seen for L, C and D. Component A is absent from the nucleated red blood cells of the chicken and the frog. 4. Sea urchins contain three LMW*RNA components with migrations different from L, A, C and D. These components account for about 0.1% of the cellular RNA. 5. Insects contain only one LMW*RNA component, migrating as component L. 6. Tetrahymena, Physarum and Mycoplasmas have one component which may be a counterpart to component L in higher cells. Yeast shows no LMW*RNA components. 7. In the multicellular species the occurrence and gel electrophoretic migration of LMW*RNA components are not related to tumorigenicity, developmental stage or origin of tissue.  相似文献   

18.
Nutrients are essential for normal physiological processes in plants, and they play important roles in defence mechanisms against pathogens. Oil palms cultivated on peat are more prone to nutrient deficiency, especially micronutrients, and this may affect their susceptibility to Ganoderma species, the major threat to the sustainability of oil palm throughout South‐East Asia. This study was conducted to investigate the association of copper (Cu) and zinc (Zn) in mature oil palm to the spatial distribution of Ganoderma species in the plantations on peat. Foliar samples (frond 17) of oil palm from two plantations (Betong and Miri) on peat in Sarawak, Malaysia, were collected based on the spatial distribution pattern of Ganoderma, and total Cu and Zn were quantified spectrometrically. The experiment was conducted twice at a 1‐year interval. The concentrations of Cu and Zn were significantly lower in oil palms from infected areas in contrast to those from uninfected areas. In addition, oil palms in infected areas in Miri suffered Cu and Zn deficiencies. Furthermore, Cu and Zn were significantly lower in the oil palms in Miri that had higher Ganoderma occurrence, as compared to those in Betong, which had significantly higher Cu and Zn but lower Ganoderma occurrence.  相似文献   

19.
大蒜化学成分的气-质联用分析   总被引:3,自引:0,他引:3  
本文采用环己烷、乙酸乙酯和正丁醇对大蒜(Allium sativum L.)新鲜鳞茎的95%乙醇提取物进行萃取,并与水蒸气蒸馏法提取的挥发油成分进行比较,用GC-MS对其成分进行定性和定量分析.在环己烷萃取物中共检出112个成分,鉴定了38个化合物,占环己烷萃取物总量的80.08%;在乙酸乙酯萃取物中检出86个成分,鉴定了26个化合物,占乙酸乙酯萃取物总量的56.70%;在正丁醇萃取物中未检出挥发性成分.在水蒸气蒸馏法提取的挥发油中共检出109个成分,鉴定了29个化合物,占挥发油总量的83.58%.大蒜95%乙醇提取物的环己烷和乙酸乙酯萃取物及大蒜挥发油中皆以含硫化合物为主.在环己烷和乙酸乙酯萃取物中,阿霍烯的含量分别为生药的0.00395%和0.00145%,大蒜中阿霍烯含量达0.00540%.  相似文献   

20.
The leaves of Lippia origanoides Kunth are used in culinary as flavoring regional dishes and remedy for gastrointestinal and respiratory diseases in the Amazon region. The circadian and seasonal study of its essential oil was characterized by GC and GC–MS analysis. The oil components were grouped into monoterpenes, sesquiterpenes and phenylpropanoids, during the dry and rainy season. The main constituents were (E)-methyl cinnamate, (E)-nerolidol, p-cymene, 1,8-cineole, carvacrol, α-pinene, (E)-caryophyllene and γ-terpinene, with great variation throughout the year. In this work, we are reporting the occurrence of a new chemotype for L. origanoides, characterized by an essential oil rich in (E)-methyl cinnamate and (E)-nerolidol, with fruity-woody odor, reminiscent of cinnamon, strawberry and wood. The oil yield varied from 1.7% to 4.6%, which is considered a significant value for the production of essential oils on an industrial scale. This new chemotype may have ecological, chemosystematics and taxonomic significance in the management and economic utilization of the species.  相似文献   

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