Study of the Association between Genotypic Potential and Linoleic Acid Tolerance with Microbial Production of Conjugated Linoleic Acid

Probiotic bacteria have been shown
to produce the bioactive conjugated
linoleic acid (CLA) from linoleic acid (LA), this being associated
with a detoxifying mechanism. Primers employed in genotypic selection
are generally species-specific. Therefore, this work aimed to identify
CLA producers by previously screening genes encoding enzymes involved
in LA isomerization with primers designed based on conserved motifs
among different species. Moreover, it was intended to evaluate the
relation of LA tolerance with CLA production potential. Genotypically
positive strains were further cultured with LA and CLA quantified.
At least one of the screened genes was detected in 39 out of 85 strains,
where designed primers allowed the identification of more potential
producers than reported ones. The LA tolerance (<1–5 mg/mL)
was shown to be independent of genotypical positivity/negativity.
Only four strains exhibited CLA production (4.94–312.39 μg/mL).
Thus, primers targeting conserved motifs are more efficient in the
selection of potential CLA producers, however, this identification
cannot rely solely on genotypic screening and LA tolerance.