Sucrose phosphorylase and invertase activities in bacteria

Leuconostoc species from coconut toddy and from cabbags, Acetobarter xylinumn and a Klebsiella species were grown in a sucrose-phosphate medium. The Klebsiella sp. had the fastest rate of growth followed by Leuconostoc from cabbage, Acetobacter xylinumn and Leuconostoc from toddy. The time taken by them to reach the late log phase was 9 - 10 h, 12 - 14 h, 24 - 30 h and 60 - 72 h respectively. The invertase from all four species was found in the 20,000g supernatant. The activity of invertase in A. xylinum, Leucinistoc (toddy); Klebsiella and Leluconostoc (cabbage) was 0.66, 8.06, 45.0 and 77.7 units per mg protein respectively. Invertase was inactivated when the crude enzyme preparation was stored at 0⁰C in half saturated neutral ammonium sulphate solution for 2 to 3 days. The invertase of Klebsiella and that of Leuconostoc sp. from cabbage were inhibited by 5×10^-2 M EDTA to the extent of 85% and 67% respectively suggesting that it may be a metallo-enzyme. The growth rate of the Klebsiella sp. was decreased by two-fold when 5×10^-2 M EDTA was present in the culture medium. Sucrose phosphorylase activity was detected in the 20,000g supernatant of A.xylinum. This enzyme could not be detected in the other three bacteria even after the inhibition of invertase and phosphatase activities.