The extracellular enzyme beta-glucosidase, present in a culture
filtrate and produced by Aspergillus niger, was concentrated up to 700 times by two-phase
partitioning. The two-phase systems were achieved by dissolving dextran and poly(ethylene
glycol) in the culture filtrate in such proportions that the lower phase, containing
the enzyme, consisted of a very small volume compared with the upper phase. The enzyme
had high affinity for the lower phase when the system contained 100 mM KSCN at pH
8.0, and the recoveries of beta-glucosidase were in the range of 85-95% with a concentrating
factor of 60-720 times. At the same time, the enzyme was purified 2-3 times. (C) 1998
Elsevier Science B.V. All rights reserved.
