sp. are probiotic microorganisms, and some of them are able to produce
conjugated linoleic acid (CLA) via the bio-hydrogenation of linoleic acid (LA). Both CLA and LA are
polyunsaturated fatty acids commonly used in the prevention and control of cardiovascular disease,
high cholesterol, and cancer, among other ailments. The carbon source is one variable that can affect
the growth and characteristics of these bacteria. Molecules called prebiotics are known to benefit
human health by stimulating the growth and activity of probiotic bacteria present in the intestinal
microflora. The aim of this study was to evaluate how different oligosaccharides affect the growth and
fatty acid profile of Lactobacillus plantarum
(NRRL - B4496). L. plantarum
cultivation was performed in
Man-Rogosa-Sharpe (MRS) medium, and the original carbon source (glucose) in this medium was
partially or totally replaced by an oligosaccharide (isomalto-oligosaccharide (IMO) or gentiooligosaccharide
(GTO)). Then, the biomass concentration and fatty acid profile were determined using
spectrophotometry and gas chromatography, respectively.
When 50% of the glucose in the MRS medium was replaced with IMO, the maximum growth
was 2.6 g/L at 37ºC. Under the same culture conditions, the incorporation of GTO only produced 2 g/L
of biomass. At 45ºC, the growth of the bacterial culture was lower than that observed at 37ºC, reaching
only 0.4 g/L. When cultivated at 37ºC in a mixture of glucose and GTO (1:1), CLA (34%, c9t11) was
obtained from cells of L. plantarum
. However, when the cultivation was performed at 45ºC, CLA was
not obtained. When IMO was used, differences in CLA content were not observed between L.
cultivated with glucose or with IMO present; however, vaccenic acid was produced.
Conclusions: Lactobacillus plantarum
grow well when a mixture of IMO and glucose is used as the
carbon source. However, this mixture does not improve the CLA content, most likely due to high
enzymatic activity that promotes the conversion of CLA to vaccenic acid. Additionally, GTO is likely
less readily metabolized by this strain. Thus, the enzymatic activity is likely lower and less CLA is
converted to vaccenic acid, resulting in an accumulation of CLA.