Extracellular beta-D-fructofuranosidase elaborated by Streptococcus salivarius strain 51: preparation, and mode of action on a levan and on homologues of inulobiose.

Streptococcus salivarius strain 51 produces an extracellular beta-D-fructofuranosidase when grown in a levan-containing medium. The enzyme hydrolyses levan, and inulo-biose, -tetraose, -pentaose, and -hexaose, but has negligible effects on inulin, inulotriose, and inuloheptaose. The branching in S. salivarius strain 51 levan is through a single (2 yields 1)-beta-D linkage.