Usporedba mikrobiološke slike signalnog raka (Pacifastacus leniusculus) i uskoškarog raka (Pontastacus leptodactylus)

undergraduate thesis

• Title (english): Comparison of the microbial gut composition of the signal crayfish (Pacifastacus leniusculus) and the narrow-clawed crayfish (Pontastacus leptodactylus)
• Author: Ana Straga
• Mentor: Jadranka Frece (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for General Microbiology and Food Microbiology); Zagreb
• Defense date and country: 2022-09-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Slatkovodne ekosustave u Hrvatskoj nastanjuje sedam vrsta rakova. Cilj ovog istraživanja bio je usporediti mikrobiološku sliku rakova, a korištene su domaća vrsta Pontastacus leptodactylus i invazivna strana vrsta Pacifastacus leniusculus. Ispitana je prisutnost bakterija mliječne kiseline (BMK) i mikroorganizama uzročnika zdravstvene neispravnosti hrane (enterobakterija, sulfitoreducirajućih klostridija i koagulaza-pozitivnih stafilokoka) s obzirom da se ovi rakovi koriste u prehrani ljudi. Dobiveni rezultati su pokazali da nema značajne razlike u mikrobiološkoj slici ovih dvaju rakova te da koncentracije ispitanih mikroorganizama prelaze one dopuštene pravilnikom pa takvi rakovi nisu sigurni za konzumaciju. Bakterije mliječne kiseline su pronađene samo kod autohtone vrste raka P. leptodactylus u koncentraciji od 2×10¹ CFU/g. Za utvrđivanje roda i vrste detektiranih BMK potrebno je provesti dodatnu identifikaciju.

Abstract (english)

Freshwater ecosystems in Croatia are inhabited by seven crayfish species. The aim of this research was to compare the microbial gut composition of crayfish, using the domestic species Pontastacus leptodactylus and the invasive foreign species Pacifastacus leniusculus. The presence of lactic acid bacteria (LAB) and microorganisms that cause food contamination (enterobacteria, sulphite-reducing clostridia and coagulase-positive staphylococci) were examined, considering that these crayfish are used in human nutrition. The obtained results showed that there are no significant differences in the microbial gut composition of these two crayfish, and that the concentrations of tested microorganisms exceed those allowed by national guidelines, so such crabs are not safe for consumption. Lactic acid bacteria were found only in the autochthonous type of crayfish P. leptodactylus in a concentration of 2×10¹ CFU/g. To determine the genus and species of detected LAB it is necessary to carry out additional identification.

• Keywords: mikrobiološka analiza; bakterije mliječne kiseline; slatkovodni rakovi
• Keywords (english): microbial analysis; lactic acid bacteria; freshwater crabs
• Language: croatian
• URN:NBN: urn:nbn:hr:159:914038
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-04-08 10:15:34