Limited hydrolysis of levan by a levanpolyase system

Loewenberg & Reese, 1957; Ben-Tovim & Hestrin, 1957; Zelikson (Ben-Tovim), 1958; Schlubach, Hohn & Repening, 1959) which deserves further study.Unexpected speci- ficity features distinguish some of these systems.It is shown in this paper that the activity of one of the systems, 'levanpolyase', is specifically directed towards linkages near branch points in levan.The distribution and types of levanases encountered in a range of micro-organiss are considered.Attention is also directed to the feature that the prior history of cells can exert a regulatory effect on the specificity range of induced fructosidase activities.In this paper oligosac- charides in which a reducing fructose moiety bears hexosyl or polyhexosyl at carbon atom 1 or 6 will be designated as 1-R-or 6-R-fructose respectively. METHODS AND MATERIALSThe levan used was prepared from a sucrose culture of Aerobacter levanicum as described by Feingold, Avigad & Hestrin (1956), except as otherwise is specified.