CHARACTERIZATION OF GLUCANSUCRASES AND FRUCTANSUCRASES PRODUCED BY WILD STRAINS LEUCONOSTOC MESENTEROIDES URE13 AND LEUCONOSTOC MESENTEROIDES LM17 GROWN ON GLUCOSE OR FRUCTOSE MEDIUM AS A SOLE CARBON SOURCE

摘要

A study on the production of soluble and cell wall-bound glucansucrases (GS) and fructansucrases (FS) by Leuconostoc mesenteroides URE13 and L. mesenteroides Lml7 during their growth on media containing sucrose, glucose or fructose as a main carbon source was carried out. The changes in the enzyme activity, the assimilation of sugars and the formation of metabolites during the cultivation were measured and compared. Soluble and cell wall-bound GS and FS were determined using SDS-PAGE, and in situ analysis. The results showed that glucose and fructose have a different effect on GS and FS production. Both strains of Leuconostoc produce GS and FS with molecular masses of (170-180) kDa and 120 kDa, respectively. In addition, L. mesenteroides URE13 produced a 300 kDa extracellular GS, during the cultivation on media containing glucose or fructose. This confirmed that the production is not only sucrose-dependent but is also detected when other sugars are used. To our knowledge, this is the first attemptto understand the correlation between the activities of GS, mannitol dehydrogenase and lactate dehydrogenase.