Naslov (srp)

Potencijal primene autohtonih bakterija mlečne kiseline kao antilisterijskih kultura u proizvodnji hrane : doktorska disertacija

Autor

Ivanović, Marina, 1975-

Doprinosi

Šolević Knudsen, Tatjana, 1969-
Živković, Dušan, 1959-
Mirković, Milica M., 1985-
Miočinović, Jelena, 1975-
Radulović, Zorica, 1962-

Opis (eng)

L. monocytogenes plays an especially important role among food contaminants, as it can cause severe clinical disease. Its containment is, therefore, of paramount importance for food safety. Application of natural antilisterial isolates in production allows for the production of high value foodstuffs, with guaranteed safety and preserved sensory properties. The aim of this dissertation was to investigate the antilisterial activity of autochthonous lactic acid bacteria (LAB) strains, originating from traditional cheeses from Serbia, through their use in food production. The PFMI565 isolate was selected among 200 isolates from Sjenica cheese as it showed the strongest antilisterial activity. It was identified as E. durans by partial gene sequencing for 16S rRNA. The study examined the activity of the E. durans PFMI565 strain, as well as strains L. lactis subsp. lactis 563 and L. lactis subsp. lactis biovar. diacetylactis BGBU1-4 from previous studies. Bacteriocin production of E. durans PFMI565 was excluded by testing and a significant effect of an organic acid, together with other inhibitory compounds, was established. Hydrogen peroxide production was confirmed, and diacetyl production was detected and quantified by HSS gas chromatography with ECD detection. The strains showed good technological properties for use in food production, and the best antimicrobial activity to L. monocytogenes ATCC19111, was demonstrated by BGBU1-4 and PFMI565 strains. L. lactis subsp. lactis 563, used alone, showed no antilisterial effect, so it is excluded from further research. Diffuse test method was used to demonstrate the sensitivity of PFMI565 and BGBU1-4 to antibiotics significant for clinical practice. Antibiotic-labelled strains PFMI565str and BGBU1-4rif were used to produce food, individually or in combinations, together with L. monocytogenes added in concentrations of 103, 104 and 105 cfu/g. Investigation of antilisterial activity using a cheese model system demonstrated a statistically significant difference in the number of pathogen cells, compared to the control, showing the best autochthonous strains antilisterial activity in samples with initially 103 cfu/g L. monocytogenes on day 14, decreasing number of L. monocytogenes below 100 cfu/g. It was proven that PFMI565str and BGBU1-4rif, in the production of UF milk cheese, inhibit the growth of L. monocytogenes, and the best results was achieved on day 21, in sample with 103 cfu/g L. monocytogenes, decreasing pathogens number below 100 cfu/g, whereby the strain BGBU1-4rif showed better activity by day 35. By applying autochthonous strains, cheese with improved sensory quality was obtained, with the maximum quality (%) of 84.10 - 94.60, which is significantly better than cheeses that use commercial starter cultures (56.40 - 85.90). In kajmak, antilisterial activity was proven in all samples with added cultures and. On day 14, the best results were achieved, with a reduction in the number of L. monocytogenes below 100 cfu/g in samples with initially 103 cfu/g. Poorer pathogen inhibition was observed for salmon, where the pathogens number was not reduced below 100 cfu/g, during the entire period. Satisfactory viability of the autochthonous strains during food production and storage was confirmed, and in all samples was 107-108 cfu/g. The findings suggest that strains PFMI565 and BGBU1-4, used as protective cultures, can provide protection from L. monocytogenes in different food products, while at the same time, as additional cultures, they may have an impact on the improvement of sensory properties of cheese.

Opis (srp)

Posebnu vaţnost meĊu kontaminantima hrane ima L. monocytogenes, jer moţe uzrokovati pojavu ozbiljnih kliniĉkih bolesti, pa je njena kontrola veoma znaĉajna sa aspekta bezbednosti hrane. Primena prirodnih antilisterijskih izolata u proizvodnji hrane, omogućuje dobijanje visokovrednih namirnica sa garancijom bezbednosti i oĉuvanja senzornih svojstava. Cilj ove disertacije je bio da se, kroz primenu u proizvodnji hrane, ispita antilisterijsko dejstvo autohtonih bakterija mleĉne kiseline (BMK), poreklom iz tradicionalnih sireva sa podruĉja Srbije. Izolat PFMI565 je odabran na osnovu najsnaţnije antilisterijske aktivnosti od 200 izolata iz Sjeniĉkog sira. Sekvenciranjem dela gena za 16S rRNK, identifikovan je kao E. durans. Praćena je aktivnost soja E. durans PFMI565, i sojeva L. lactis subsp. lactis 563 i L. lactis subsp. lactis biovar. diacetylactis BGBU1-4, iz ranijih istraţivanja. Testiranjem inhibitorne aktivnosti je iskljuĉena produkcija bakteriocina soja E. durans PFMI565, a ustanovljen znaĉajan efekat organske kiseline i uticaj drugih inhibitornih jedinjenja. Produkcija vodonik-peroksida je potvrĊena, a primenom HSS gasne hromatografije sa ECD detektorom kvantifikovana je produkcija diacetila. Ispitivani sojevi su pokazali dobra tehnološka svojstva za primenu u proizvodnji hrane, a najbolju antimikrobnu aktivnost prema L. monocytogenes ATCC19111, ispoljili su BGBU1-4 i PFMI565. L. lactis subsp. lactis 563, samostalno primenjen, nije pokazao antilisterijsko dejstvo, pa je iskljuĉen iz daljih istraţivanja. Metodom difuzionog testa je utvrĊena senzitivnost PFMI565-a i BGBU1-4 na antibiotike znaĉajne u kliniĉkoj praksi. Sojevi obeleţeni rezistencijom na antibiotike PFMI565str i BGBU1-4rif su primenjeni u hrani, pojedinaĉno ili u kombinacijama, zajedno sa L. monocytogenes koja je dodata u koncentracijama 103, 104 i 105 cfu/g. Ispitivanjem antilisterijskog delovanja u modelu sira, dobijena je statistiĉki znaĉajna razlika u broju patogena u odnosu na kontrolu, pri ĉemu je pokazano najbolje antilisterijsko dejstvo autohtonih sojeva u uzorcima sa inicijalnim 103 cfu/g L. monocytogenes u 14. danu, sniţavanjem broja L. monocytogenes ispod 100 cfu/g. Dokazano je da su PFMI565str i BGBU1-4rif, u proizvodnji sira od UF mleka, inhibirali rast L. monocytogenes, a najbolji rezultati su postignuti u 21. danu u varijantama sa 103 cfu/g L. monocytogenes, sniţavanjem broja patogena ispod 100 cfu/g, pri ĉemu je soj BGBU1-4rif pokazao bolju aktivnost do 35. dana. Primenom autohtonih sojeva, dobijeni su sirevi sa poboljšanim senzornim svojstvima, sa 84,40 - 94,60 %, od maksimalnog kvaliteta, znaĉajno boljim od sireva sa komercijalnim starterom (56,40 - 85,90). U kajmaku je dokazano antilisterijsko delovanje u svim varijantama sa dodatim kulturama, a 14. dana, postignuti su najbolji rezultati, u uzorcima sa inicijalnim 103 cfu/g, sa brojem L. monocytogenes manjim od 100 cfu/g. Slabija inhibicija patogena zabeleţena je u svim uzorcima lososa, pri ĉemu broj patogena nije bio sniţen ispod 100 cfu/g tokom celog perioda. PotvrĊena je dobra vijabilnost autohtonih sojeva tokom proizvodnje i skladištenja hrane i u svim uzorcima se kretala 107-108 cfu/g. Rezultati istraţivanja sugerišu da autohtoni sojevi PFMI565 i BGBU1-4, primenjeni kao protektivne kulture, mogu da obezbede zaštitu od L. monocytogenes u razliĉitim proizvodima, a istovremeno kao dodatne kulture, mogu uticati na poboljšanje senzornih svojstava sira.

Opis (srp)

Tehnološko inženjerstvo - Tehnološka mikrobiologija / Technological engineering- Industrial microbiology Datum odbrane: 25.97.2022.

Jezik

srpski

Datum

2022

Licenca

© All rights reserved

Predmet

OSNO - Opšta sistematizacija naučnih oblasti, Poljoprivredna proizvodnja. Poljoprivredna tehnologija

OSNO - Opšta sistematizacija naučnih oblasti, Prehrambena industrija. Industrijska mikrobiologija

bakterije mleĉne kiseline, antilisterijska aktivnost, sir od UF mleka, kajmak, losos

637.065:664.8.03(043.3)

OSNO - Opšta sistematizacija naučnih oblasti, Poljoprivredna proizvodnja. Poljoprivredna tehnologija

OSNO - Opšta sistematizacija naučnih oblasti, Prehrambena industrija. Industrijska mikrobiologija

lactic acid bacteria, antilisterial activity, UF milk cheese, kajmak, salmon