*2.1. Materials*

The buffalo whey used in this work was provided by the dairy factory "La Perla del Mediterraneo" (Battipaglia, Italy) in the framework of research and development processes in collaboration with the Dept. of Experimental Medicine, Bioteknet and the manufacturing facility. The company performed ultrafiltration on polyethersulphone 20 kDa spiral membranes (filtering surface 40 m<sup>2</sup> ) and provided (i) a sample (15–20 L) of the retentate concentrated fraction that was spray-dried in the framework of this research and used as substrate for the growth of *L. fermentum* and for wound healing assays (ii) a permeate that was nanofiltered and characterized.

*L. fermentum* was isolated from buffalo milk (data not shown). All salts and medium components for bottle and fermentation experiments were supplied by Sigma-Aldrich (St. Louis, MO, USA). Yeast extract was furnished by Organotechnie (La Corneuve, France), while sulphuric acid was purchased by Biochem s.r.l. (Turin, Italy). Dulbecco's Modified Eagle Medium (DMEM), Fetal bovine serum(FBS), penicillin–streptomycin, Phosphate Buffer Solution, (PBS) and Trypsin are provided by Gibco Invitrogen (Milan, Italy). HaCaT

cells, a spontaneously transformed non-tumorigenic human keratinocytes cell line, were provided by the Zooprophylactic Institute (Brescia, Italy).
