Taxonomy of obligately homofermentative and facultatively heterofermentative lactobacilli in pig faeces

AIMS: Identification and characterization of obligately homofermentative and facultatively heterofermentative strains of Lactobacillus spp. isolated from the faeces of pigs that had been raised under different conditions. METHODS AND RESULTS: The phenotypic relatedness of the isolated strains and reference strains were determined by numerical analysis of total soluble cell protein patterns and simple physiological and biochemical tests. Of the 23 strains isolated from faeces, nine were obligately homofermentative and 14 facultatively heterofermentative. The strains clustered at r > or = 0.61 with Lactobacillus amylovorus (seven strains), Lactobacillus crispatus (one strain), Lactobacillus plantarum (14 strains) and Lactobacillus intestinalis (one strain). CONCLUSIONS: Results obtained from the physiological and biochemical tests confirmed the identity of the isolates as determined by numerical analysis of total soluble cell protein profiles. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the association of Lact. crispatus and Lact. intestinalis with the gastro-intestinal tract of pigs.