Zymographic assay to differentiate Lactobacillus reuteri among other Lactobacillus

SUMMARY A simple method is reported that allows the phenotypic differentiation of Lactobacillusreuteri strains among other Lactobacillus . The detection of the enzyme 1,3-propane-diol:NAD oxidoreductase in non-denaturing PAGE, a constitutive enzyme of Lb. reuteri involved in the production of 1,3-propanediol, is used. Other member of the genuswere reported as 1,3 propanediol producers ( Lactobacillus brevis and Lactobacillusbuchneri ), both of their enzymes showed differential properties to that of Lb. reuteri .Under the conditions used in the study, the strain Lb. reuteri CRL1100 was found toproduce 15 % more 1,3-PDL (11.5 ± 0.41 gl -1 ) in comparison with the reference strain Lb. reuteri DSM 20016 (10.0 ± 0.37 gl -1 ). Keywords Lactobacillus reuteri, 1,3-propanediol:NAD oxidoreductase, zymogram, 1,3-propa-nediol. 1 – INTRODUCTION Besides ethanol, glycerol is the main product of yeast fermentation (L AFON -L AFOUR-CADE , 1983). In spoiled wines or ciders glycerol is usually degraded causing bitter compo-nents like acrolein; generated from a chemical equilibrium with 3-hydroxypropionaldehyde,the intermediary component in the production of 1,3-propanediol (1,3-PDL) (C