Abstract

BAEZA-JIMENEZ, R. et al. Effect of glucose on 1,3-propanediol production by Lactobacillus reuteri. Rev. Mex. Ing. Quím [online]. 2011, vol.10, n.1, pp.39-46. ISSN 1665-2738.

Given the increasing demand for biofuels and biopolymers, there is an existing need to investigate new and more efficient alternatives for their production. 1,3-propanediol (PDO) is a typical product of glycerol fermentation by bacteria such as Klebsiella; however, Lactobacillus reuteri, a recognized probiotic, offers an alternative for its production in glucose/glycerol co-fermentations. The aim of the present work was to study the effect of glucose on PDO production using different initial concentrations (20-200 mM) under anaerobic conditions by L. reuteri ATCC 23272. Biomass was monitored by optical density at 600 nm and substrates and products profiles were analyzed by HPLC. The highest PDO concentration attained was 16.81 g/L in flasks (37°C, 100 mM glucose/200 mM glycerol for 16 h at pH 5.5, under anaerobic conditions). At fermenter level, a production of 28.69 g/L was reached under the same conditions, except glucose (200 mM) and glycerol (400 M). Stoichiometric and kinetic parameters showed that the 0.5 glucose/glycerol ratio allowed the highest PDO production. The flux calculated for glucose (F_glu) and glycerol (F_gly) in the co-fermentations with the highest PDO productions, had almost a 0.5 ratio.

Keywords : Lactobacillus reuteri; 1,3-propanediol; glucose; glycerol; co-fermentation.