Lactobacillus ruminis is a predominant lactic acid producing bacterium in the caecum and rectum of the pig

Abstract

To identify the predominant lactic acid producing bacteria in the small intestine, caecum and the rectum of the healthy pig. Samples obtained from the large intestine of healthy pigs post-mortem were cultured using a modified agar-MRS medium in roll tubes. Thirteen isolates were selected on the basis of their morphological characteristics and Gram stain reaction for gene sequencing. These isolates were characterized by DNA sequence analysis of 16S rDNA. Eight isolates were identified as Lactobacillus ruminis, two as Enterococcus faecium, one as Mitsuokella multiacidus and two as Escherichia coli. This is the first report of Lact. ruminis as the dominant lactic acid bacteria in the large intestine of the pig. The results suggest that Lact. ruminis is a dominant bacterium in the large intestine of the healthy pig. Future work should focus on the role of this bacterium in relation to the physiological function of the intestine and the health of the animal.