INVESTIGADORES
MOZZI Fernanda Beatriz
congresos y reuniones científicas
Título:
Mannitol production by Lactobacillus reuteri CRL1101 using a low-cost culture medium
Autor/es:
M.E. ORTIZ; G. VIGNOLO; R.R. RAYA; F. MOZZI
Reunión:
Simposio; FoodMicro 2012. 23rd International ICFMH Symposium. Global Issues in Food Microbiology; 2012
Resumen:
Mannitol
is a natural polyol mainly used in the food industry as low-calorie sweetener
(referred as E421 in the European Union) being applicable for diabetic food products. As food ingredient, it is also used in
"breath-freshening" products due to its negative enthalpy and
capability to mask undesirable tastes of many compounds. In addition, it has
been claimed to display health-promoting (antioxidant, anticariogenic) effects.
In the last years, efforts have been made to produce mannitol through
fermentations using lactic acid bacteria. To produce mannitol in an efficient
and cost-effectively way, a few low-cost substrates have been recently
investigated. In this work, we aimed to design a minimum culture MRS-based medium
using sugarcane molasses as carbon source for the production of mannitol by Lactobacillus reuteri CRL 1101. The
effect (by omission or addition) of each MRS component on cell growth (OD and
cell count), pH and mannitol production (HPLC) by L. reuteri CRL 1101 were determined in a minimum culture medium at 37°C under free- and
controlled-pH fermentations for 24 h. The formulated low-cost culture medium, containing
beef extract, yeast extract, and either glucose plus MnSO4 or
sugarcane molasses, showed similar microbial growth patterns to that obtained
in MRS. L.
reuteri CRL 1101 successfully produced
good amounts of mannitol using this low-cost minimum culture medium. Optimal cell
growth (log CFU/ml: 8.9 ± 0.2) and mannitol production (150.3 ± 11.3 mM, Ymtl:
100 %) were obtained in free-pH cultures after 24 h of fermentation. These values were improved (cell growth, log CFU/ml: 9.2 ± 0.3 and mannitol
production, 180.1
± 15.9 mM) in fermentations under constant-pH of 5.0 although
with a lower yield (Ymtl: 89 %). The
design of an inexpensive and more competitive culture medium for the
biotechnological production of mannitol represents an important approach for the
microbial synthesis of mannitol at industrial scale.