Purification and Characterization of Glycerol Dehydratase from Lactobacillus reuteri

Abstract

A coenzyme B12-dependent glycerol dehydratase from Lactobacillus reuteri has been purified and characterized. The dehydratase has a molecular weight of approximately 200,000, and sodium dodecyl sulfatepolyacrylamide gel electrophoresis yielded a single major band with a molecular weight of 52,000. Km values for substrates and coenzyme B12 were in the millimolar and the submicromolar range, respectively.

Purification, characterization and subunits identification of the diol dehydratase of Lactobacillus collinoides

“…As reported by Talarico et al [13] for the glycerol dehydratase of L. reuteri, the enzyme of L. collinoides was stable in media containing high potassium and 1,2-propanediol concentrations. A first purification was attempted with a phosphate buffer containing these two compounds.…”

“…The highest activity was obtained between 8.5 and 9.25 with a maximum at pH 8.75. This was in accordance with the optimum pH of the dehydratase of K. pneumoniae (pH 8.6) [28] but not with the L. reuteri enzyme (pH 7.2) [13]. Temperature was also studied for its influence on the 1,2-propanediol conversion to propionaldehyde.…”

“…Data for L. brevis, L. reuteri and L. sp. 208 A are taken from [20] [13], and [10], respectively. p-CMB, p-chloromercuribenzoate, -, not determined.…”

“…In Lactobacillus reuteri, a bacterium resident of the gastrointestinal tract of humans, the AdoCbl-dependent glycerol dehydratase has been purified. This enzyme seemed to exhibit a particular structure of four identical subunits of 52 kDa each [13]. Up to now, this is the only communication of the composition of a dehydratase enzyme obtained by purification in this bacterial genera.…”

In vitro investigations of the effect of probiotics and prebiotics on selected human intestinal pathogens

“…Twenty eight of the strains tested inhibited E. coli growth, whilst 12 of the 47 strains tested inhibited growth of S. typhimurium. A plethora of information surrounds the proposed probiotic activity of L. reuteri [14], primarily ascribed to production of an antimicrobial protein called reuterin [15,16], whose synthesis requires glycerol in the growth medium [17]. This was omitted from media used in the current investigation, since it is not known how much glycerol would be present in the gut, to become available for utilisation by L. reuteri, in the production of reuterin [14].…”