Alginate (A7003), medium viscosity alginate (A2033), low viscosity alginate (A2158), fucoidan (F5631), laminaran (L9634), gum Arabic (G9752), oat spelt xylan, and polygalacturonic acid (P3889) were obtained from Sigma-Aldrich. A sodium alginate from Laminaria hyperborea stipes was kindly provided by DuPont (Landerneau, France). High viscosity alginate (02154723, MP Biochemicals) and very low viscosity alginate (A18565, Alfa Aesar) were kindly provided by Dr Richard Blackburn (University of Leeds). Tamarind xyloglucan, potato galactan, guar galactomannan, sugar beet arabinan and citrus pectin were obtained from Megazyme International (Bray, Ireland).
The MM- and GG-blocks of alginates were prepared using the DuPont sodium alginate according to Heyraud et al. (1996) (link). A 0.5% alginate solution was hydrolyzed for 5 h at 100 °C in 0.3 M HCl. After selective precipitation and centrifugation, the blocks were dialyzed, freeze-dried, and re-suspended in distilled water, and respective M/G compositions monitored by NMR. The MM- and GG-blocks were further fragmented using alginate M-lyase (Lundqvist et al., 2012 (link)) and alginate G-lyase (Thomas et al., 2013 (link)), respectively. The enzymatic degradation and the purification of the released oligosaccharides was performed as described previously (Thomas et al., 2013 (link)).
The MM- and GG-blocks of alginates were prepared using the DuPont sodium alginate according to Heyraud et al. (1996) (link). A 0.5% alginate solution was hydrolyzed for 5 h at 100 °C in 0.3 M HCl. After selective precipitation and centrifugation, the blocks were dialyzed, freeze-dried, and re-suspended in distilled water, and respective M/G compositions monitored by NMR. The MM- and GG-blocks were further fragmented using alginate M-lyase (Lundqvist et al., 2012 (link)) and alginate G-lyase (Thomas et al., 2013 (link)), respectively. The enzymatic degradation and the purification of the released oligosaccharides was performed as described previously (Thomas et al., 2013 (link)).