Sucrose phosphorylase of the rumen bacteriumPseudobutyrivibrio ruminisstrain A

Abstract

Aims: To verify the taxonomic affiliation of bacterium Butyrivibrio fibrisolvens strain A from our collection and to characterize its enzyme(s) responsible for digestion of sucrose. Methods and Results: Comparison of the 16S rRNA gene of the bacterium with GenBank showed over 99% sequence identity to the species Pseudobutyrivibrio ruminis. Molecular filtration, native electrophoresis on polyacrylamide gel, zymography and thin layer chromatography were used to identify and characterize the relevant enzyme. An intracellular sucrose phosphorylase with an approximate molecular mass of 52 kDa exhibiting maximum activity at pH 6·0 and temperature 45°C was identified. The enzyme was of inducible character and catalysed the reversible conversion of sucrose to fructose and glucose‐1‐P. The reaction required inorganic phosphate. The Km for glucose‐1‐P formation and fructose release were 3·88 × 10−3 and 5·56 × 10−3 mol l−1 sucrose, respectively – while the Vmax of the reactions were −0·579 and 0·9 μmol mg protein−1 min−1. The enzyme also released free glucose from glucose phosphate. Conclusion: Pseudobutyrivibrio ruminis strain A utilized sucrose by phosphorolytic cleavage. Significance and Impact of the Study: Bacterium P. ruminis strain A probably participates in the transfer of energy from dietetary sucrose to the host animal.

Phylogenetic systematics of Butyrivibrio and Pseudobutyrivibrio genomes illustrate vast taxonomic diversity, open genomes and an abundance of carbohydrate-active enzyme family isoforms

“…16S rDNA phylogeny on fewer strains, performed by Kasperowicz et al . [62], showed that the CF1b strain groups closely with the type strain P. ruminis A12-1, which is concurrent with our own 16S rDNA findings.…”

“…16S rDNA phylogeny on fewer strains, performed by Kasperowicz et al . [ 62 ], showed that the CF1b strain groups closely with the type strain P. ruminis A12-1, which is concurrent with our own 16S rDNA findings. Whilst 16S rDNA analysis has historically been thought to be a reliable means of establishing distant relationships between organisms [ 63 ], extensive diversity has been found within the 16S rDNA of certain genomes [ 64, 65 ].…”