Capability of biohydrogenation of linoleic acid in rumen bacterium Pseudobutyrivibrio xylanivorans Mz5T | Sposobnost biohidrogenacije linolne kisline pri vampni bakteriji Pseudobutyrivibrio xylanivorans Mz5T

Inglés. Conjugated linoleic acids (CLA) are positional and geometrical isomers of octadecadienoic acid (18:2) and have a variety of beneficial effects for the humans and animals. Main producers of CLA are rumen bacteria, mainly from the genus Butyrivibrio. Many researches are directed towards increasing the concentration of CLA in food products of animal origin. This could be achieved also with the application of suitable probiotic strains of bacteria. One of those is also Pseudobutyrivibrio xylanivorans Mz5T. This strain is capable to grow in the presence of linoleic acid (LA, ie. the CLA precursor), at least up to concentrations of 200 µg LA/ml. Under these conditions, the lag phase is prolonged, and the growth is slowered down, too. Consequently the bacteria retain their activity. After 24 hour incubation in the medium with LA, the studied strain biohydrogenates the LA to trans-vaccenic acid, which can be then transformed back to CLA by tissue ∆9-desaturase, which is present in the animal tissue. The strain Mz5Tcould be used as a probiotic in animal nutrition in order to increase the quality of the food products of animal origin.

Esloveno. Konjugirane linolne kisline (CLA) so skupina pozicijskih in geometrijskih izomer oktadekadienojske kisline (18:2) in imajo vrsto ugodnih učinkov pri ljudeh in ûivalih. Glavni tvorci CLA so vampne bakterije, predvsem iz rodu Butyrivibrio. Vse več je raziskav, s katerimi se preiskuöajo načini za povečanje vsebnosti CLA v prehranskih proizvodih ûivalskega izvora, kar bi lahko dosegli z uporabo primernih probiotičnih sevov bakterij. Eden izmed njih je tudi Pseudobutyrivibrio xylanivorans Mz5T. Ta sev je sposoben rasti v gojiöču, kjer je prisotna linolna kislina (LA, to je prekurzor CLA) vsaj do koncentracije 200 µg mlñ1. Pri takih pogojih se rast sicer upočasni, a bakterije öe vedno ohranijo svojo aktivnost. Po 24 urah gojenja v gojiöču z LA proučevani sev izvede biohidrogenacijo LA do trans-vakcenske kisline, ki jo tkivni encim ∆9-desaturaza, prisoten v tkivu ûivali, lahko pretvori nazaj do CLA. Z uporabo seva Mz5Tkot probiotika v prehrani ûivali bi tako lahko povečali kakovost končnih ûivil ûivalskega izvora