magistrsko delo
Barbara Grum (Author), Polona Jamnik (Reviewer), Barbara Jeršek (Mentor)

Abstract

Mikroalge so zaradi sposobnosti proizvajanja širokega spektra organskih spojin, med katerimi imajo številne bioaktivne lastnosti, vse bolj proučevane na različnih znanstvenih področjih. Med temi spojinami so še posebej zanimive tiste s protimikrobnim in protiadhezivnim delovanjem. V raziskavi smo proučevali bioaktivne lastnosti mikroalg vrst Arthrospira platensis in Chlorella vulgaris pri bakterijah vrst Escherichia coli, Pseudomonas aeruginosa ter Staphylococcus aureus in kvasovkah vrste Candida albicans. Določali smo protimikrobno delovanje z metodo razredčevanja v mikrotitrski plošči, s katero smo izbranim ekstraktom mikroalg določili minimalno inhibitorno koncentracijo (MIK) ter protiadhezivno delovanje z metodo barvanja s kristal vijoličnim, za kar smo uporabili subinhibitorno koncentracijo (0,1 MIK), saj nismo želeli vpliva ekstraktov na rast, temveč samo na adhezijo. Rezultati protimikrobnega delovanja so pokazali, da sta učinkovita ekstrakta CMAS in CMAC (CMA: ekstrakcija z mešanico kloroform, metanol, aceton; S: A. platensis; C: C. vulgaris) pri bakterijah vrste S. aureus (MIK = 10 mg/ml), medtem ko ostali ekstrakti niso imeli protimikrobnega učinka pri izbranih mikroorganizmih (MIK > 20 mg/ml). V nadaljevanju raziskave smo ugotovili, da protiadhezivno deluje ekstrakt MC (M: ekstrakcija z metanolom; C: C. vulgaris) pri bakterijah vrste S. aureus (28,8 % inhibicija), medtem ko je ekstrakt CMAS povečal adhezijo bakterij vrste S. aureus, in ekstrakt MS bakterijam vrst S. aureus in P. aeruginosa. Slednje bi lahko pripisali napaki pri meritvi absorpcije, do katere je prišlo zaradi temne obarvanosti obeh ekstraktov. Rezultati naše raziskave kažejo, da mikroalge vrst A. platensis in C. vulgaris predstavljajo velik potencial v razvoju novih in učinkovitih bioaktivnih sredstev, vendar so potrebne dodatne raziskave.

Keywords

mikroalge;ekstrakti;bakterije;kvasovke;protimikrobno delovanje;protiadhezivno delovanje;biofilm;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [B. Grum]
UDC: 579.24:582.2/.3
COBISS: 78626563 Link will open in a new window
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Downloads: 20
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Other data

Secondary language: English
Secondary title: Bioactive properties of Arthrospira platensis and Chlorella vulgaris extracts
Secondary abstract: Microalgae are becoming increasingly popular in various scientific fields due to their ability to produce a wide range of organic compounds, among which many have bioactive properties. Among the mentioned compounds, those with antimicrobial and anti-adherence activities are particularly interesting. Such microalgae also include Arthrospira platensis and Chlorella vulgaris, whose bioactive properties against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans strains were researched in our study. We determined antimicrobial activity with minimum inhibitory concentration (MIC) of microalgae extracts with the broth microdilution method. We also determined antiadhesive activity with crystal violet staining method, for which we used sub-inhibitory concentration (0.1 MIC) of microalgae extracts, as we did not want to influence the growth but only adhesion of selected microorganisms. The results of antimicrobial activity showed that only CMAS and CMAC extracts (CMA: extraction with mixture of chloroform, methanol, acetone; S: A. platensis; C: C. vulgaris) were effective against S. aureus (MIC = 10 mg/ml), while other extracts had no antimicrobial effect against selected microorganisms (MIC > 20 mg/ml). In the continuation of our study, we found that MC extract had an antiadhesive effect against S. aureus (28.8% inhibition), while CMAS extract increased adhesion of S. aureus and MS extract increased adhesion of P. aeruginosa and S. aureus. This could be attributed to an error in absorbance measurement due to dark coloration of both extracts. Results of our research, together with results of researches of other authors proved that A. platensis and C. vulgaris microalgae represent a great potential in development of new and effective bioactive agents, but further researches are needed.
Secondary keywords: microalgae;extracts;bacteria;yeasts;antimicrobial activity;antiadhesive activity;biofilm;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: XII, 53 f., [2] f. pril.
ID: 13587585