Comparison of Procedures for Isolation of Malolactic Bacteria from Wine

Abstract

Malolactic bacteria were isolated from wine by direct streaking on modified Rogosa agar plates followed by aerobic incubation or incubation in a high CO₂ atmosphere, or enrichment in modified Rogosa broth before streaking and aerobic incubation (designated aerobic, high CO₂ and enrichment incubations, respectively). The incubation temperature was 30°C throughout. More cocci were isolated with the aerobic and high CO₂ incubations than with the enrichment incubation. Preliminary identification tests indicated that 41 lactobacilli, 34 leuconostocs and 15 pediococci were isolated by the aerobic and high CO₂ incubations while 45 lactobacilli and only two leuconostocs and one pediococcus were isolated with the enrichment incubation. The high C0₂ incubation seemed the most suitable for the isolation of leuconostocs.