Selekcija i molekularna identifikacija bakterijskih izolata s kutikule slatkovodnih rakova koji inhibiraju rast micelija patogena Aphanomyces astaci Schikora, 1906

undergraduate thesis

• Title (english): Selection and molecular identification of bacterial isolates from freshwater crayfish cuticle which inhibit the mycelial growth of pathogen Aphanomyces astaci Schikora, 1906
• Author: Karla Orlić
• Mentor: Ana Bielen (mentor)
• Mentor: Sandra Hudina (mentor)
• Committee member: Sandra Hudina (predsjednik povjerenstva)
• Committee member: Tomislav Ivanković (član povjerenstva)
• Committee member: Luka Valožić (član povjerenstva)
• Committee member: Alan Moro (član povjerenstva)
• Committee member: Ivan Čanjevac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2021-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Slatkovodni deseteronožni rakovi, ključne vrste slatkovodnih staništa, ugroženi su širenjem invazivnih stranih vrsta rakova i bolesti račje kuge, koju uzrokuje patogeni mikroorganizam Aphanomyces astaci Schikora, 1906. Osim što patogen ugrožava prirodne populacije zavičajnih vrsta slatkovodnih rakova, uzrokuje i velike štete u akvakulturi. Kemijski tretmani koji se trenutno koriste za kontrolu ovog patogena štetni su za rakove, ljude i ekosustav pa je potrebno razviti učinkovite i ekološki prihvatljive metode kontrole, poput biokontrole. Stoga je cilj ovoga istraživanja testiranje inhibicijskog potencijala bakterijskih izolata prisutnih na kutikuli dvije vrste rakova: uskoškarog raka - Pontastacus leptodactylus (Eschscholtz, 1823) (zavičajna vrsta) i signalnog raka - Pacifastacus leniusculus (Dana, 1852) (invazivna strana vrsta). Bakterijski izolati su identificirani masenom spektrometrijom MALDI-TOF i sekvenciranjem gena 16S rRNA. Većina sakupljenih izolata pripada koljenu Proteobacteria (69 %), zatim Bacteroidetes (17 %) i Firmicutes (8 %). Nadalje, testirana je sposobnost svakog izolata da uspori ili zaustavi rast micelija A. astaci koristeći in vitro testove inhibicije te su izolati razvrstani u dvije skupine: inhibitori (33 %) i ne-inhibitori (67 %). Više od polovice izolata inhibitora (56 %) pripadalo je rodu Pseudomonas. Ovo istraživanje je prvi korak u identifikaciji bakterijskih izolata koji bi mogli biti upotrijebljeni za biokontrolu patogena A. astaci

Abstract (english)

Freshwater decapod crayfish are threatened by the spread of invasive crayfish species and crayfish plague. This disease is caused by the pathogen Aphanomyces astaci Schikora, 1906, and has detrimental effects on native European crayfish populations and on astaciculture. Existing chemical treatments are toxic to crayfish, humans and the ecosystem, so the development of effective and environmentally friendly pathogen control methods is urgently needed. Therefore, the aim of this study was to test the A. astaci-inhibitory potential of bacterial isolates from the cuticle of two the narrow-clawed crayfish Pontastacus leptodactylus (Eschscholtz, 1823) (native species) and the signal crayfish Pacifastacus leniusculus (Dana, 1852) (invasive species). Identification by MALDI-TOF mass spectrometry and 16S rRNA gene sequencing revealed that most of the isolates belonged to the phylum Proteobacteria (69 %), followed by Bacteroidetes (17 %) and Firmicutes (8 %). The isolates were tested for their ability to slow or stop the growth of A. astaci mycelium by in vitro plate assay and were classified as inhibitors (33%) or non-inhibitors (67 %). More than half of the identified inhibitors (56 %) belonged to the genus Pseudomonas. This study represents the first step towards the identification of bacterial isolates that could be used for biocontrol of A. astaci.

• Keywords: biokontrola; račja kuga; epibionti; test inhibicije
• Keywords (english): biocontrol; crayfish plague; epibionts; plate inhibition assay
• Language: croatian
• URN:NBN: urn:nbn:hr:217:846767
• Study programme: Title: Environmental Sciences; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) struke znanosti o okolišu (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-07-22 10:29:07