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Antimicrobial properties of endophytic fungi
Get PDFMaailmas on üha suuremaks probleemiks inimese haigustekitajate ravimiresistentsus. Samuti on kliimamuutusi seostatud suureneva metsapatogeenide levikuga. Selles vallas omavad potentsiaali endofüütsed seened – seened, kes elavad taimekudede vahel ja ei põhjusta peremeestaimedel enamasti haigusnähtusid. Nende ainevahetusproduktidest võib leida uusi aineid, mis on antibiootiliste või antifungaalsete omadustega ning omavad potentsiaali bioloogilises tõrjes.
Töö eesmärgiks oli uurida valitud endofüütsete seente antimikroobseid omadusi bakterite ja puitu kahjustavatate seente suhtes. Bakteritest kasutati Staphylococcus aureus, Escherichia coli ja Proteus vulgaris´t. Lisaks uuriti mõju pärmseenele Candida albicans. Metsapatogeenidest tehti katseid Heterobasidion annosum (nii männilt kui kuuselt pärit viljakehade puhaskultuurid), Diplodia sapinea, Fomes fomentarius, Fomitopsis pinicola, Piptoporus betulinus ja Lophodermium seditiosum´iga. Uuritavad endofüüdid on pärit Eestist, Nigeeriast ja Prantsuse Gujaanast. Kokku kasutati töös 56 endofüüti.
Töös antakse ülevaade teemaga seonduvast kirjandusest ja patogeenidest. Uurimustöös kasutati kahte eri metoodikat: endofüütide vedelfiltraate kasutati S. aureus, E. coli, C. albicans vastase mõju uurimisel ning kaksikkultuurimeetodi kaudu tuvastati endofüütide inhibeeriv mõju P. vulgaris ja puitu lagundavate seente puhul.
Uurimusliku töö tulemusena leiti üks endofüüt, mis inimpatogeenide uuringus inhibeeris E. coli kasvu. P. vulgaris katses oli patogeeni kasvu pidurdavaid endofüüte 15. Puitu lagundavate seente uuringus andsid Eesti taimedest isoleeritud endofüüdid troopika omadest paremaid tulemusi. Kõige enam inhibeeriti kasvu Lophodermium seditiosumi puhul, antagonismi protsent oli erinevate endofüütide puhul 19,4-44,1%.
Antud uuringust võib järeldada, et endofüütsed seened olid efektiivsemad P. vulgaris ja puitu lagundavate seente tõrjes. Tulevikus saaks antud tulemusi rakendada bioloogilises tõrjes, kuid esmalt tuleks tuvastada spetsiifilised ained, mis omavad inhibeerivat efekti. Seejärel saaks looduses nakatada puid kõige efektiivsemate endofüütidega.Drug resistance of the human pathogens is an increasing problem in the world. Also, increasing spread of forest pathogens have been accociated with the changes in the climate. Endophytic fungi - fungi that exist between plant tissues and do not cause disease to the host, have great potential in this area. Among their metabolic products there could be new substances that have antibiotic or antifungal properties and have potential for biological control.
The aim of this research was to investigate antimicrobial properties of selected endophytic fungi in regards to bacteria and wood decaying fungi. Bacteria used in this research were Staphylococcus aureus, Escherichia coli and Proteus vulgaris. Effect on yeast fungus Candida albicans was also investigated. Heterobasidion annosum (fruiting bodies pure cultures from spruce and pine), Diplodia sapinea, Fomes fomentarius, Fomitopsis pinicola, Piptoporus betulinus ja Lophodermium seditiosum were the used forest pathogens. Endophytes used are from Estonia, Nigeria and French Guyana. All together 56 endophytes were used in this reasearch.
An overview of literature used and pathogens is given. There were two methods used: liquid filtrates were used to investigate the impact against S. aureus, E. coli, C. albicans and dual culture method to detect inhibitory efect of endophytes on P.vulgaris and wood decaying fungi.
As a result of this research, one endophyte that inhibited E.coli in human pathogen survey was found. In the survey of P.vulgaris, 15 endophytes inhibited the pathogen. In the study with wood decaying fungi, endophytes inhibited from Estonia showed better results. The most inhibited pathogen was Lophodermium seditiosum, antagonism percent with different endophytes was 19,4 – 44,1 %.
In conclusion of this study, endophytic fungi were more efficient against P.vulgaris and wood decaying fungi. In the future these results could be used in biological control, but first specific substances with inhibitory effect should be established. After that trees should be infected with the most effective endophytes
Endophytic fungi isolated from nettle lady´s mantle and broadleaf plantain
No full textTöö eesmärgiks oli ravimtaimedest endofüütsete seente eraldamine puhaskultuuri, nende kirjeldamine ja määramine. Uuritavad taimed olid suur teeleht (Plantago major), kõrvenõges (Urtica dioica) ja harilik kortsleht (Alchemilla vulgaris).
Endofüütide vähese uurituse tõttu on võimalik leida uusi mikroorganisme elusate taimede seesmistest kudedest. Endofüüte on järjest rohkem hakatud uurima, seoses nende suure osatähtsusega nii looduslikes kooslustes, põllumajanduses kui meditsiinis. Käesolevas töös loodeti leida uusi seenetüvesid ravimtaimedest, mida edaspidises töös saaks kasutada haigustõrjeks.
Uurimusliku töö tulemusena eraldati 85 puhaskultuuri, millede identifitseerimiseks mõõdeti nende morfoloogilisi tunnuseid (sh koniidi ja hüüfi suurused, kasvukiirused, kultuuri värvus) ning eraldati sekveneerimiseks ITS rDNA. Selle alusel määrati 12 kultuuri: Lewia infectoria, Hypoxylon howeanum, Fusarium culmorum, Apodus deciduus, Leptosphaeria sp, Pleosporales sp, Colletotrichum clavatum, Hypoxylon fuscum, Colletotrichum clavatum, Phoma multirostrata (2), Phoma sp (2).
Edaspidi tahetakse uurida, kumb toodab inimesele kasulikku bioaktiivset ainet, kas seen või ravimtaim ning kas erinevatel taimedel on erinevad endofüütsed seened.The aim of this research was to isolate endophytic fungi to pure culture, to describe and determine them. The studied plants were broadleaf plantain (Plantago major), stinging nettle (Urtica dioica) and lady's mantle (Alchemilla vulgaris).
Due to the fact that endophyte-related research is quite new, it is possible to discover new microorganisms in inner tissues of plants. The research on endophytes has been growing over time, because of their relative importance to natural community, agriculture and medicine. This research is looking for fungal strains from herbal plants, which could be used for disease control in further work.
As a result, 85 pure cultures were isolated from plants, which were identified by measuring their morphological features (including conidia and hypha sizes, growth rate, pure culture colour) and separating ITS rDNA for sequencing. On this basis the 12 culture: Lewia infectoria, Hypoxylon howeanum, Fusarium culmorum, Apodus deciduus, Leptosphaeria sp, Pleosporales sp, Colletotrichum clavatum, Hypoxylon fuscum, Colletotrichum clavatum, Phoma multirostrata (2), Phoma sp (2).
In the future, researchers want to find out whether fungi or herbs produce benefitial bioactive substance for people, and do different plants have different endophytic fungi
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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