Dextran production by Lactobacillus sakei MN1 coincides with reduced autoagglutination, biofilm formation and epithelial cell adhesion

40 p.-7 fig.-4 fig.supl.In this work we have investigated two dextran-producing lactic acid bacteria, Lactobacillus sakei MN1 and Leuconostoc mesenteroides RTF10, isolated from fermented meat products. These bacteria synthesise dextran when sucrose, but not glucose, is present in the growth medium. The influence of dextran on bacterial aggregation, adhesion and biofilm formation was investigated in cultures challenged with sucrose or glucose. For Lb. sakei MN1, the synthesis of the dextran drastically impaired the three processes; in contrast it had no effect on Lc. mesenteroides RTF10. Therefore, the influence of dextran on probiotic properties of Lb. sakei MN1 was tested in vivo using gnotobiotic zebrafish models. The bacterium efficiently colonised the fish gut and inhibited the killing activity of Vibrio anguillarum NB10[pOT11]. Furthermore, under conditions of dextran synthesis, the adhesion of Lb. sakei MN1 to the epithelial cells decreased, without greatly affecting its anti V. anguillarum activity.This work was supported by the Spanish Ministry of Economics and Competitiveness [grants AGL2012-40084C03-01 and AGL2015-65010-C3-1-R] and by the Agriculture and Fisheries Department of the Basque Government [project VIVAQUA], and II is the recipient of a PhD fellowship from Technological centres foundation-Iñaki Goenaga.Peer reviewe