magistrsko delo
Sara Recek (Author), Tatjana Košmerl (Reviewer), Lea Pogačnik (Mentor), Barbara Jeršek (Co-mentor)

Abstract

V naši raziskavi smo preverjali protimikrobni učinek olupka korenine japonskega dresnika (Fallopia japonica), sahalinskega dresnika (Fallopia sachalinensis) in češkega dresnika (Fallopia x bohemica). Pripravili smo etanolne ekstrakte s koncentracijo 600 mg/mL in s stabilnim radikalom DPPH• preverili njihovo antioksidativno učinkovitost (AOU). Vsebnost skupnih fenolnih spojin smo določali z modificirano spektrofotometrično metodo po Singletonu in Rossiju (1965), posamezne fenolne spojine (katehin, epikatehin, polidatin in resveratrol) pa s tekočinsko kromatografijo visoke ločljivosti (HPLC). Ekstrakt japonskega dresnika se je izkazal za pomemben vir resveratrola in polidatina, najvišjo AOU in vsebnost skupnih fenolnih spojin pa smo določili v ekstraktu sahalinskega dresnika. Protimikrobni učinek ekstraktov smo določali za bakterije vrst Listeria monocytogenes, Escherichia coli in za kvasovke vrste Candida albicans z metodo razredčevanja v mikrotitrski ploščici v kombinaciji z metodo štetja kolonij na trdem gojišču tako, da smo ocenili minimalno inhibitorno koncentracijo (MIC) in minimalno bakteriocidno koncentracijo (MBC) ekstraktov. Ekstrakt sahalinskega dresnika je bil najučinkovitejši pri inhibiciji kvasovk vrste C. albicans (37 mg/mL), ekstrakt japonskega dresnika pa je imel edini bakteriocidno aktivnost za bakterije vrste E. coli (75 mg/mL). Ugotovili smo, da so bili ekstrakti z višjo AOU in vsebnostjo skupnih fenolnih spojin bolj uspešni pri inhibiciji in/ali bakteriocidni aktivnosti na izbranih mikroorganizmih.

Keywords

dresnik;Fallopia;antioksidativna učinkovitost;skupne fenolne spojine;resveratrol;polidatin;epikatehin;katehin;protimikrobno delovanje;MIC;MBC;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [S. Recek]
UDC: 582.665:66.094.3.097.8:547.56:579.24
COBISS: 4993656 Link will open in a new window
Views: 1290
Downloads: 415
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Other data

Secondary language: English
Secondary title: Bioactive effect of non-native knotweed root extracts (Fallopia japonica, Fallopia sachalinensis and Fallopia x bohemica)
Secondary abstract: The aim of our study was to determinate an antimicrobial activity of a shell of the root of Japanese knotweed (Fallopia japonica), Giant knotweed (Fallopia sachalinensis) and Bohemian knotweed (Fallopia x bohemica). Ethanol extracts with a concentration of 600 mg/mL were prepared and tested for antioxidant capacity (AOC) with stable DPPH• radical. Total phenolic content was determined by modified Singleton and Rossi method (1965) while individual phenols (catechin, epicatechin, polydatin and resveratrol) were detected by high-performance liquid chromatography (HPLC). Japanese knotweed extracts proved to be an important source of resveratrol and polydatin while the highest AOC and total phenolic content ware determined in Giant knotweed extract. Antimicrobial activity of extracts was evaluated with Listeria monocytogenes, Escherichia coli and Candida albicans. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of extracts were determined by combination of broth microdilution and plate-count methods. Giant knotweed extract with concentration of 37 mg/mL was the most effective in inhibition of C. albicans. Japanese knotweed was the only taxon with bactericidal activity against E. coli (75 mg/mL). We can conclude that knotweed taxes with higher AOC and total phenolic content had higher inhibition and/or bacteriocidal activity against selected microbial strains.
Secondary keywords: knotweed;Fallopia;antioxidant activity;total phenolic content;resveratrol;polydatin;epicatechin;catechin;antimicrobial activity;MIC;MBC;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: XI, 57 f., [4] f. pril.
ID: 10984150