Utjecaj mikotoksina na parametre rasta bakterija mliječne kiseline, potencijalnih starter kultura za proizvodnju fermentiranih namirnica

master's thesis

• Title (english): Effect of mycotoxins on parameters of lactic acid bacteria, potential starter cultures for the production of fermented foodstuffs
• Author: Jure Prtenjača
• Mentor: Ksenija Markov (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: 2017-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Prema procjeni FAO-a, 25% hrane proizvedeno u svijetu kontaminirano je mikotoksinima. Zbog toksičnog učinka, ne samo na ljude, životinje i biljke već i mikroorganizme, postoji zabrinutost zbog ulaska mikotoksina u prehrambeni lanac čovjeka, tzv. „carry over“ efektom. Cilj ovog rada bio je istražiti utjecaj aflatoksina B1 (AFB1) i zearalenona (ZEA) na rast i morfološke osobine odabranih sojeva bakterija mliječne kiseline Lactobacillus plantarum K1, Lactobacillus plantarum B, Leuconostoc mesenteroides i Pediococcus pentosaceus, potencijalnih starter kultura za proizvodnju fermentiranih namirnica. Mikrobni rast ovisi o uvjetima okoline u kojoj se mikroorganizmi nalaze kao i izloženosti kemijskim agensima, a toksično djelovanje mikotoksina najčešće se očituje kroz inhibiciju rasta. Rast bakterija mliječne kiseline (BMK) ispitivan je u prisutnosti AFB1 i ZEA različitih koncentracija tijekom 24 satnog uzgoja u MRS podlozi, a izražen je brojanjem poraslih kolonija na čvrstoj hranjivoj podlozi u obliku log10 CFU/mL. Metoda mikrometrije korištena je za određivanje veličine stanica, kao morfološke osobine. Iz dobivenih rezultata uočeno je da istraživani mikotoksini u različitim koncentracijama imaju utjecaj na veličinu, broj živih stanica, ali ne i na konačan broj ispitivanih stanica BMK.

Abstract (english)

According to FAO estimates, 25% of food produced in the world is contaminated with mycotoxins. Because of the toxic effect not only on humans, animals and plants, but also on microorganisms, there is concern about the introduction of mycotoxins into the human food chain, by so-called „carry over“ effect. The aim of this paper was to investigate the effects of aflatoxin B1 (AFB1) and zearalenone (ZEA) on growth and morphological properties of selected strains of lactic acid bacteria Lactobacillus plantarum K1, Lactobacillus plantarum B, Leuconostoc mesenteroides and Pediococcus pentosaceus, potential starter cultures for fermented foods. Microbial growth depends on the conditions of the environment in wich microorganisms are found as well as exposure to chemical agents, and the toxicity of mycotoxins is most often manifested through growth inhibition. The growth of lactic acid bacteria (LAB) was investigated in the presence of AFB1 and ZEA at various concentrations during 24 hours of cultivation in the MRS broth and expressed by counting the growing colonies on a solid nutrient medium in the form of log10 CFU/mL. The micrometric method was used to determine the cell size as a morphological trait. From the obtained results it is observed that mycotoxins at different concentrations have an effect on size, number of live cells but not on the final number of LAB cells.

• Keywords: aflatoksin B1; zearalenon; bakterije mliječne kiseline; broj bakterija; morfološke osobine bakterija
• Keywords (english): aflatoxin B1; zeralenon; lactic acid bacteria; bacterial count; morphological characteristics of bacteria
• Language: croatian
• URN:NBN: urn:nbn:hr:159:503234
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-11-07 10:20:45