Dextransucrase mutants of Leuconostoc mesenteroides BI-08 strain.

: We have isolated mutants constitutive for dextransucrase from Leuconostoc mesenteroides--BI-08 using ethyl methane sulfonate. The mutants produced mainly extracellular dexrtansucrase on glucose media with higher activity (3.5-4 times) than what the parental strain produced on glucose and 2 times more than what the parental strain produced on sucrose. Based on endo-dextranase from Penicillium hydrolysis, mutant BI-08 dextransucrases produced slightly different dextrans when they were elaborated on a glucose medium and on a sucrose medium Differences in viscosity, water solubility, susceptibility to endo-dextranase hydrolysis dextrans elaborated by different mutants grown on glucose media and sucrose media were found. SDS-PAGE analysis shows that the molecular masses of the dextransucrases from the studing mutants were 130-180 kDa.