Fig 1.
Conversion of fructose into mannitol catalyzed by the mannitol 2-dehydrogenase (MDH) enzyme.
Fig 2.
Cell growth and MDH activity of L. reuteri CRL 1101 grown in MRSG and MRSGF at 37°C for 24 h.
a) Growth kinetics in both media; b) Specific MDH activity in both media; c, d) Carbohydrate consumption and mannitol production in MRSG and MRSGF, respectively. Statistical analysis in Fig 2b was performed using two-way ANOVA followed by Bonferroni post-test. A value of p<0.05 was considered statistically significant.
Fig 3.
Cell growth and MDH activity of L. reuteri CRL 1101 grown in CDMG and CDMGF at 37°C for 24 h.
a) Growth kinetics in both media; b) Specific MDH activity in both media; c, d) Carbohydrate consumption and mannitol production in CDMG and CDMGF, respectively. Statistical analysis in Fig 3b was performed using two-way ANOVA followed by Bonferroni post-test. A value of p<0.05 was considered statistically significant. ns p>0.05, * p<0.05, ** p<0.01, *** p<0.001, **** p<0.0001.
Fig 4.
Relative expression of the mdh gene in L. reuteri CRL 1101 in presence (CDMGF) and absence (CDMG) of fructose incubated at 37°C after 8 and 24 h of incubation.
Statistical analysis was performed using one sample t-test comparing all values with an hypothetical value of one (control condition = CDMG 8 h). Differences between groups were considered to be significant at a p value of <0.05. ns p>0.05, * p<0.05, ** p<0.01.
Table 1.
CT values of mdh and pyrG genes of L. reuteri CRL 1101 grown in CDM in absence and presence of fructose (CDMG and CDMGF) for 8 and 24 h.
Fig 5.
Representative gel images of proteomes of L. reuteri CRL 1101 obtained under the four studied conditions.
a, b) 8 h of incubation in the absence (control) and in the presence of fructose, respectively; c, d) 24 h of incubation in the absence and in the presence of fructose, respectively. Circles indicate the identified spots by MALDI-TOF. Linear pH gradient was used.
Fig 6.
Proteins of Lactobacillus reuteri CRL 1101 over-expressed or repressed at 8 h of incubation in the presence of fructose, separated by 2DE and identified by Maldi ToF–MS-MS.
Fig 7.
Proteins of Lactobacillus reuteri CRL 1101 over-expressed or repressed at 24 h of incubation in the presence of fructose, separated by 2DE and identified by MS.
Fig 8.
Maldi ToF—MS-MS mapping of MDH.
Signals are assigned through the position within the protein as presented in italics.
Table 2.
Shotgun proteomic identification of proteins of L. reuteri CRL 1101 whole lysates, grown in the absence and in the presence of fructose for 24 h.
Score and mass values are reported along with the number of identified peptides (matches) and gene locus tag. In the current experimental conditions, matches with score values >30 were considered proof of identity or extensive homology (p<0.01).