diplomsko delo
Mateja Stipič (Author), Andreja Čanžek Majhenič (Reviewer), Barbara Jeršek (Mentor)

Abstract

Namen naloge je bil določiti protibakterijsko delovanje eteričnih olj in hidrolatov šetraja (Satureja hortensis), lovorja (Laurus nobilis), origana (Origanum vulgare), grške bazilike (Ocimum basilicum) in rožmarina (Rosmarinus officinalis) proti bakterijam vrst Escherichia coli in Staphylococcus aureus. Med eksperimentalnim delom smo v raziskavo vključili še hidrolat morske alge (Laminaria digitata) in etanolni ekstrakt pire (Triticum aestivum ssp. spelta). Protibakterijsko delovanje omenjenih snovi smo preizkušali z metodo razredčevanja v mikrotitrski ploščici. Natančne minimalne inhibitorne koncentracije (MIC) in minimalne baktericidne koncentracije (MBC) smo določili z metodo štetja kolonij na trdem gojišču. Za bakterije vrste E. coli so se vrednosti MIC za eterična olja gibale od 1,56 mg/ml do 6,25 mg/ml, vrednosti MBC pa od 1,56 mg/ml do 12,5 mg/ml. Najboljšo protibakterijsko aktivnost je pokazalo eterično olje origana, ki je imelo najnižje vrednosti MIC. Za bakterije vrste E. coli je znašala vrednost MIC eteričnega olja origana 1,56 mg/ml, za bakterije vrste S. aureus pa 0,78 mg/ml. 50 % hidrolati niso pokazali protibakterijske aktivnosti. 75 % hidrolata šetraja in origana sta rast obeh testiranih vrst bakterij zavrla, medtem ko je bilo za inhibicijo bakterijske rasti potrebno uporabiti 100 % hidrolat rožmarina. Hidrolata lovorja in grške bazilike nista pokazala protibakterijskega delovanja. Ekstrakt pire preizkušen direktno v tekočem gojišču triptični sojin bujon (TSB) ni zavrl rasti bakterij vrste E. coli, je pa zavrl rast bakterij vrste S. aureus. Ko smo ekstrakt pire topili v etanolu in nato dodali gojišču TSB je zavrl rast obeh vrst bakterij. Eksperimentalno smo pokazali, da imajo eterična olja in hidrolati v ustrezni koncentraciji potencial zaviranja rasti bakterij in da je njihovo delovanje odvisno od vrste začimbne rastline. Eterična olja so bolj učinkovita sredstva za zaviranje rasti bakterij kot hidrolati, potrdimo pa lahko tudi, da so Gram pozitivne bakterije bolj občutljive za eterična olja in hidrolate kot Gram negativne bakterije.

Keywords

eterična olja;hidrolati;začimbne rastline;protimikrobno delovanje;Escherichia coli;Staphylococcus aureus;minimalna inhibitorna koncentracija;minimalna baktericidna koncentracija;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [M. Stipič]
UDC: 579.24:547.913:633.83
COBISS: 4943736 Link will open in a new window
Views: 1333
Downloads: 435
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Other data

Secondary language: English
Secondary title: Antimicrobial activity of essential oils and hydrosols of selected spice plants
Secondary abstract: The purpose of our work was to determine antibacterial activity of essential oils and hydrosols made of summer savory (Satureja hortensis), laurel (Laurus nobilis), oregano (Origanum vulgare), Greek basil (Ocimum basilicum) and rosemary (Rosmarinus officinalis) against Escherichia coli and Staphylococcus aureus. During the work we decided to include also the hydrosol of sea algae (Laminaria digitata) and ethanolic extract of spelt (Triticum aestivum ssp. spelta). The main method we used to determine antibacterial activity of the substances was broth microdilution method. To get the precise minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) we performed the plate count method. For E. coli MIC values for essential oils were from 1.56 mg/ml to 6.25 mg/ml, and MBC values from 1.56 mg/ml to 12.5 mg/ml. The essential oil of oregano showed the best antibacterial activity with the lowest MIC of 1.56 mg/ml for E. coli and 0.78 mg/ml for S. aureus. In a concentration of 50 %, hydrosols did not show antibacterial activity, while 75 % hydrosols of summer savory and oregano did inhibit the growth of bacteria. As well did the 100 % hydrosol of rosemary. Hydrosols of laurel and Greek basil did not show antibacterial activity. The extract of spelt tested directly in triptic soy broth (TSB) did not inhibit growth of E. coli, but showed antibacterial activity against S. aureus. The extract of spelt diluted in ethanol and then tested in TSB inhibited growth of both tested bacteria. In this study we proved that essential oils and hydrosols do have a potential to inhibit the growth of bacteria, and that their activity differs due to plant sort. Overall, essential oils are more effective against bacteria than hydrosols. We can also confirm that Gram positive bacteria are more susceptible to essential oils and hydrosols than Gram negative bacteria.
Secondary keywords: essential oils;hydrosols;spice plants;antimicrobial activity;Escherichia coli;Staphylococcus aureus;minimal inhibitory concentration;minimal bactericidal concentration;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VIII, 21 f.
ID: 10958842