Identification and physiological characteristics of heterofermentative strains ofLactobacillusfrom South African red wines

Nineteen atypical heterofermentative strains of Lactobacillus spp. isolated from South African red wines were identified with the API 50 CHL system and by computerized comparison of their total soluble cell protein patterns. Eleven strains were identified as Lactobacillus hilgardii and eight strains as L. brevis. Three strains of L. hilgardii and three strains of L. brevis produced small amounts of H2S in peptone water supplemented with 001%l-cysteine. All strains produced mannitol from fructose. Proteolytic activity was detected in all except two strains of L. hilgardii. Strains capable of digesting gelatine, hydrolized casein, but not vice versa. The excessive production of sulphur-containing compounds, mannitol and acetaldehyde by lactic acid bacteria could have serious quality implications for the wine industry. Three strains of L. hilgardii and all strains of L. brevis decarboxylated l-malic acid to l-lactic acid.