title: Phosphorolytic cleavage of sucrose by sucrose-grown ruminal bacterium Pseudobutyrivibrio ruminis strain k3.
abstract: Rumen bacterium Pseudobutyrivibrio ruminis strain k3 utilized over 90% sucrose added to the growth medium as a sole carbon source. Zymographic studies of the bacterial cell extract revealed the presence of a single enzyme involved in sucrose digestion. Thin layer chromatography showed fructose and glucose-1-phosphate (Glc1P) as end products of the digestion of sucrose by identified enzyme. The activity of the enzyme depended on the presence of inorganic phosphate and was the highest at the concentration of phosphate 56 mmol/L. The enzyme was identified as the sucrose phosphorylase (EC 2.4.1.7) of molar mass approximately 54 kDa and maximum activity at pH 6.0 and 45 degrees C. The calculated Michaelis constant (Km) for Glc1P formation and release of fructose by partially purified enzyme were 4.4 and 8.56 mmol/L while the maximum velocities of the reaction (Vlim) were 1.19 and 0.64 micromol/L per mg protein per min, respectively.
authors.affiliation: The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110, Jablonna near Warsaw, Poland. katarzyna.stan@wp.pl
authors.forename: K
authors.initials: K
authors.lastname: Stan-Glasek
authors.forename: A
authors.initials: A
authors.lastname: Kasperowicz
authors.forename: W
authors.initials: W
authors.lastname: Guczyńska
authors.forename: M
authors.initials: M
authors.lastname: Piknová
authors.forename: P
authors.initials: P
authors.lastname: Pristas
authors.forename: K
authors.initials: K
authors.lastname: Nigutová
authors.forename: P
authors.initials: P
authors.lastname: Javorský
authors.forename: T
authors.initials: T
authors.lastname: Michałowski
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002855:Chromatography, Thin Layer; D003470:Culture Media / Q000737:chemistry; D004795:Enzyme Stability; D005632:Fructose / Q000378:metabolism; D005958:Glucosephosphates / Q000378:metabolism; D005964:Glucosyltransferases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D010710:Phosphates / Q000378:metabolism; D012417:Rumen / Q000382:microbiology*; D013395:Sucrose / Q000378:metabolism*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D005958:Glucosephosphates; D010710:Phosphates; D005632:Fructose; D013395:Sucrose; D002244:Carbon; C031590:glucose-1-phosphate; D005964:Glucosyltransferases; C025901:sucrose phosphorylase