( such as ultra-filtration, fractionation by polyethylene glycol, salt, glycerol and alcohol precipitation, phase partitioning and chromatography)
but I think they're using it for Dextransucrase purification(NIGAM et al., 2006; DOLS et al., 1998b; GOYAL AND KATIYAR, 1994;
KITAOKA AND ROBYT, 1998a; TSUCHIYA et al., 1955; FUKUI et al., 1974; RUSSEL, 1979; PAUL et al., 1984; LOPEZ-MUNGUIA et al., 1993; MAJUMDER et al., 2007; CHLUDZINSKI et al. 1974).
Looks like you are not producing the dextran from Leuconostoc mesenteroides...
Regards
Read this for more information(Kate C. Blanko_2012)
Article Dextran: effect of process parameters on production, purific...