doktorska disertacija
Dina Ramić (Author), Sonja Smole Možina (Mentor), Iztok Dogša (Co-mentor)

Abstract

Novi pristopi obvladovanja bakterij Campylobacter jejuni v živilski industriji so predmet številnih raziskav. Rastlinski izvlečki predstavljajo obetavne alternativne protimikrobne učinkovine za nadzor biofilma. V tej doktorski nalogi smo pripravili in testirali različne pripravke sivke vrst L. angustifolia in L. x intermedia proti filmotvornosti bakterij C. jejuni na abiotskih površinah. S filmotvornostjo smo se spoprijeli preko tarč, kot so gibljivost, pritrjevanje in medcelična komunikacija bakterij C. jejuni. Optimizirali smo metodo gojenja in preučevanja biofilma bakterij C. jejuni na abiotski površini in sicer na interfazi trdna površina/tekočina s konfokalno vrstično lasersko mikroskopijo. Poleg vpeljave visoko tlačne tekočinske kromatografije v kombinaciji s fluorescenčnim detektorjem (HPLC-FLD) smo razvili, optimizirali in nadgradili metodo preučevanja medcelične komunikacije bakterij C. jejuni z biosenzorjem V. harveyi MM30. Nova metoda je v primerjavi s HPLC-FLD natančnejša in občutljivejša. Vsi pripravki sivke so uspešno odstranili zreli biofilm bakterij C. jejuni z abiotske površine. Prav tako so vsi pripravki sivke uspešno zavrli gibljivost, pritrjevanje bakterij C. jejuni na abiotske površine in filmotvornost. Pripravki sivke niso značilno znižali koncentracije signalnih molekul avtoinduktor-2 (AI-2) v izrabljenem gojišču bakterij C. jejuni. Rezultati metode rt-PCR niso pokazali vpliva eteričnega olja sivke na izražanje gena luxS pri bakterijah C. jejuni. Transkriptomska analiza planktonske kulture bakterij C. jejuni po izpostavljenosti eteričnemu olju sivke je pokazala spremembo izražanja številnih genov, pomembnih za gibljivost, filmotvornost, metabolizem železa in stresni odziv bakterij C. jejuni. Te lastnosti predstavljajo nove, obetavne tarče za obvladovanje biofilma bakterij C. jejuni v živilski industriji.

Keywords

Campylobacter jejuni;sivka;medcelična komunikacija;biofilm;

Data

Language: Slovenian
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UL BF - Biotechnical Faculty
Publisher: [D. Ramić]
UDC: 579.22/.26:579.67:547.9
COBISS: 133773827 Link will open in a new window
Views: 16
Downloads: 11
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
Secondary title: Control of Campylobacter jejuni biofilm by inhibition of cell-to-cell communication
Secondary abstract: New approaches are being studied intensively to control Campylobacter jejuni in the food industry. Plant extracts represent promising alternative antimicrobial agents for biofilm control. In this doctoral thesis, we prepared and tested different preparations of Lavandula angustifolia and L. x intermedia against biofilm formation of C. jejuni on abiotic surfaces. Biofilm formation was challenged through targets such as motility, attachment and intercellular communication of C. jejuni. We optimized the method of culturing and studying the biofilm of C. jejuni on an abiotic surface, specifically at the solid/liquid interface, using confocal laser scanning microscopy. We developed, optimized and upgraded a method for studying the intercellular communication of C. jejuni with the V. harveyi MM30 biosensor strain, which proved to be accurate and more sensitive compared to the high pressure liquid chromatography with fluorescence detector (HPLC-FLD) method. All lavender preparations successfully removed the mature biofilm of C. jejuni from the abiotic surface. Likewise, all lavender preparations successfully inhibited the motility, attachment of C. jejuni to abiotic surfaces and biofilm formation of C. jejuni. Lavander preparations did not lower significantly the concentration of autoinducer-2 (AI-2) signalling molecules in the spent medium of C. jejuni. The rt-PCR did not show the significant effect of lavender essential oil on the expression of the luxS gene in C. jejuni. Transcriptomic analysis of the planktonic culture of C. jejuni after exposure to lavender essential oil showed that the expression of many genes important for motility, biofilm formation, iron metabolism and stress response of C. jejuni has been changed. These traits represent new, promising targets for C. jejuni biofilm control.
Secondary keywords: Campylobacter jejuni;lavandula;cell-to-cell communication;biofilm;
Type (COBISS): Doctoral dissertation
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak.
Pages: 1 spletni vir (1 datoteka PDF (XI, 93 f., [2] f. pril.)
ID: 17410069