3.21 Optimization of the growth of lactic acid bacteria in different
concentrations of pectin extracted from lemon peel.
Se sugiere presentación POSTER
Eliana Neme1,2 , Ana L. Apás1, Silvia González1, Susana D. Monserrat2, Raúl O. Pedrazza2
1 Cátedra de Salud Pública. FBQyF( Facutad de Bioquimica, Quìmica y Farmacia).UNT 2 FAZ
(Facultad de Agronomia y Zootecnia). UNT (elineme@hotmail.com)
Probiotics are microorganisms (e.g., bifidobacteria and lactobacilli) that can reach the end of the
digestive tract remaining viable; they have positive effects on consumer health, whether human
or animals.
Pectin is a polysaccharide composed of galacturonic acid monomer units with different degrees
of esterification and neutralization. Its applications include elaboration of jams, jellies, candies,
essential oils, mayonnaise and cosmetics, among others. It is a protector and regulator of the
gastrointestinal system, used in the treatment of hypercholesterolemic individuals.
The aim of this study was to evaluate the growth of probiotic lactic acid bacteria in a culture
medium supplemented with different concentrations of pectin.
Lactic bacteria studied, Enterococcus faecium (strain RRC 14) and Enterococcus faecium
(strain RRC 38), were provided by the Department of Public Health,
Chemistry and Pharmacy of the UNT. Bacteria were grown in LAPTG liquid culture medium,
containing yeast extract (1.0 g), peptone (1.5 g), tryptone (1.0 g), glucose (1.0 g), distilled water
(100 ml), pH = 7. They were incubated 24 h at 37 °C. After that, serial dilutions were performed
and 0.5 ml were inoculated in liquid LAPTG medium supplemented with different pectin
concentrations (1, 0.1, 0.5%). They were incubated at 37 ºC for 24 h and aliquots were
extracted at different times (from 0 to 24 h) to measure the OD640 in spectrophotometer. At the
same time, aliquots taken at different times were plated on solid LAPTG medium, supplemented
with different pectin concentrations, as before. Plates were incubated 72 h at 37 ºC for viable
cell count.
The results showed good growth in pectin concentrations of 0.5 and 0.1%, with the advantage
to the latter concentration where the lag phase was reduced by 75% for strain RRC38 and 50%
for strain RRC14. The viable counting when using pectin 0.1% was 1.03 x 1010 CFU/ml for
strain RRC14, and 0.74 x 1011 CFU/ml for strain RRC 38. And when using pectin 0.5%: 0.82 x
1010 CFU/ml for strain RRC14 and 0.80 x 1011 CFU/ml for strain RRC38). CFU / ml and 38
respectively RRC14 . Values were lower when using pectin 1% in the grown medium. These
results show the ability of the lactic bacteria assessed to grow at low concentrations of lemon´s
pectin with an adequate number of viable cells in a short period of incubation, giving the
possibility for using them in the formulation of a symbiotic diet.
