Diversity of ethanol‐tolerant lactobacilli isolated from Douro fortified wine: clustering and identification by numerical analysis of electrophoretic protein profiles

Eighty‐two ethanol‐tolerant (≥ 15% v/v) isolates of Lactobacillus were obtained from Douro fortified wines and associated winery equipment. The diversity and specific identity of these isolates was studied with computer‐assisted comparison of the whole‐cell, SDS‐solubilized protein profiles (as generated by SDS‐PAGE); with this method four species were identified. The majority of isolates (89%) were identified as Lact. hilgardii, and three differentiable electrophoretic groups of this species were evident. The identification was confirmed by DNA‐DNA dot‐blot hybridization studies. Also identified were one strain each of Lact. fructivorans, Lact. collinoides and Lact. mali.