Lactobacillus mucosae sp. nov., a new species with in vitro mucus-binding activity isolated from pig intestine.

A new Lactobacillus species from pig small intestine has been identified. In an attempt to isolate Lactobacillus reuteri strains carrying the putative colonization-factor gene (mub, for mucus binding) a mub-derived gene probe was used to screen pig intestinal material. A number of isolates were obtained and primary characterization showed that they were Gram-positive, catalase-negative, non-spore-forming, non-motile rods. Growth occurred at 45 degrees C but not at 15 degrees C and the DNA G+C content was 46 mol%. Cell wall analysis together with DNA-DNA hybridization and analysis of the 16S rRNA sequence revealed that the new isolates represent a previously undescribed Lactobacillus species closely related to L. reuteri, Lactobacillus fermentum and Lactobacillus pontis. The name Lactobacillus mucosae is proposed for this species and the type strain is S32T.