Sucrose phosphorylase of the rumen bacterium Pseudobutyrivibrio ruminis strain A.
OBJECTIVE
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.


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 degrees 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 K(m) for glucose-1-P formation and fructose release were 3.88 x 10(-3) and 5.56 x 10(-3) mol l(-1) sucrose, respectively - while the V(max) of the reactions were -0.579 and 0.9 mumol mg protein(-1) min(-1). The enzyme also released free glucose from glucose phosphate.


CONCLUSIONS
Pseudobutyrivibrio ruminis strain A utilized sucrose by phosphorolytic cleavage.


CONCLUSIONS
Bacterium P. ruminis strain A probably participates in the transfer of energy from dietetary sucrose to the host animal.
Kasperowicz
A
A
The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jablonna, Poland. a.kasperowicz@ifzz.pan.pl
Stan-Glasek
K
K
Guczynska
W
W
Piknova
M
M
Pristas
P
P
Nigutova
K
K
Javorsky
P
P
Michalowski
T
T