Capability of biohydrogenation of linoleic acid in rumen bacterium Pseudobutyrivibrio xylanivorans Mz5T

Abstract

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 Mz5T
could be used as a
probiotic in animal nutrition in order to increase the quality of the food products of animal
origin.