Polysaccharide hydrogels for the protection of dairy-related microorganisms in adverse environmental conditions

Osojnik Črnivec, Ilja Gasan (avtor), Neresyan, Tigran (avtor), Gatina, Yuliana (avtor), Kolmanič Bučar, Vid (avtor), Skrt, Mihaela (avtor), Dogša, Iztok (avtor), Bogovič Matijašić, Bojana (avtor), Kulikova, Irina (avtor), Lodygin, Aleksei (avtor), Poklar Ulrih, Nataša (avtor)

Adverse environmental conditions are severely limiting the use of microorganisms in food systems, such as probiotic delivery, where low pH causes a rapid decrease in the survival of ingested bacteria, and mixed-culture fermentation, where stepwise changes and/or metabolites of individual microbial groups can hinder overall growth and production. In our study, model probiotic lactic acid bacteria (L. plantarum ATCC 8014, L. rhamnosus GG) and yeasts native to dairy mixed cultures (K. marxianus ZIM 1868) were entrapped in an optimized (cell, alginate and hardening solution concentration, electrostatic working parameters) Ca-alginate system. Encapsulated cultures were examined for short-term survival in the absence of nutrients (lactic acid bacteria) and longterm performance in acidified conditions (yeasts). In particular, the use of encapsulated yeasts in these conditions has not been previously examined. Electrostatic manufacturing allowed for the preparation of well-defined alginate microbeads (180–260 µm diameter), high cell-entrapment (95%) and viability (90%), and uniform distribution of the encapsulated cells throughout the hydrogel matrix. The entrapped L. plantarum maintained improved viabilities during 180 min at pH 2.0 (19% higher when compared to the free culture), whereas, L. rhamnosus appeared to be less robust. The encapsulated K. marxianus exhibited double product yields in lactose- and lactic acid-modified MRS growth media (compared to an unfavorable growth environment for freely suspended cells). Even within a conventional encapsulation system, the pH responsive features of alginate provided superior protection and production of encapsulated yeasts, allowing several applications in lacto-fermented or acidified growth environments, further options for process optimization, and novel carrier design strategies based on inhibitor charge expulsion.

• Jezik: Angleški jezik
• Ključne besede: encapsulation, polysaccharides, hydrogels, probiotics, dairy products, lactic acid bacteria, lactose-fermenting yeasts
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: BF - Biotehniška fakulteta
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2021
• Št. strani: 15 str.
• Številčenje: Vol. 26, iss. 24, art. 7484
• PID: 20.500.12556/RUL-136619
• UDK: 664.0+579.67:615.014.6
• ISSN pri članku: 1420-3049
• DOI: 10.3390/molecules26247484
• COBISS.SI-ID: 89130755
• Datum objave v RUL: 12.05.2022

Gradivo je del revije

• Naslov: Molecules
• Skrajšan naslov: Molecules
• Založnik: MDPI
• ISSN: 1420-3049
• COBISS.SI-ID: 18462981

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.
• Začetek licenciranja: 10.12.2021

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: enkapsulacija, polisaharidi, hidrogeli, probiotiki, mlečnokislinske bakterije, kvasovke