Identification of Lactobacillus spp. Isolated from Different Phases During the Production of a South African Fortified Wine

Abstract

Fortified wines contain a high level of unfermented sugars and are prone to spoilage by alcohol-tolerant lactic acid bacteria. A total of 62 strains were isolated from various production stages of one of the more popular fortified wines produced in South Africa. The strains were identified by using numerical analysis of total soluble cell protein patterns and 16S rRNA sequence analyses. The species most frequently isolated were *Lactobacillus vermiforme* (24 strains and *Lactobacillus casei* subsp. *casei* (32 strains. Twenty-four of the strains of *L. vermiforme*, three strains of *Lactobacillus buchneri*, one strain of *Lactobacillus plantarum*, and two strains of *L. casei* subsp. *casei* were isolated from spoiled fortified wine which contained 22 % (vol/vol ethanol. The majority of strains of *L. casei* subsp. *casei* (25 of the 32 and two strains of *Lactobacillus zeae* were isolated from wine before submerged fermentation. Five strains of *L. casei* subsp. *casei* were isolated from wine undergoing submerged fermentation, with an alcohol content of 11.92 % (vol/vol. No strain was isolated from unbottled wine which underwent the complete fermentation process and with an alcohol content of 17.20 % (vol/vol. Three distinct phenotypic groups of *L. vermiforme* were identified at r >=0.70, separate from *Lactobacillus brevis*, *L. buchneri* and *Lactobacillus hilgardii*. Three phenotypic clusters have been identified for *L. casei* subsp. *casei*. This is the first report of the presence of *L. vermiforme*, *L. zeae*, *L. casei* subsp. *casei* and *L. plantarum* in fortified wines.