Phylogenetic Identification and Some Physiological Properties of Lactic Acid Bacteria Isolated from the Oral Cavities of Some Selected Students from University of Ibadan, Nigeria

Lactic Acid Bacteria (LAB) have been reported to be a component of the human and animal microbiome, functioning as probiotics. Their capacity to stick to the epithelial or mucosal surface is mostly dependent on receptor specific binding, charge, and hydrophobicity interaction. Much work have been done on the hydrophobicity and some physiological properties of LAB from different sources but there is a dearth of knowledge on those of the oral cavity, hence this study.

Oral samples were collected from respondents from different areas of the University Of Ibadan with sterile swab stick and were brought to the microbiology laboratory of the University of Ibadan for analysis. The isolates were subjected to morphological, biochemical, molecular and physiological tests using standard procedures.

In this study, nine colonies of LAB were isolated and characterized from oral samples of respondents from the University of Ibadan. They were identified as, Pedicoccus acidilactici, Leuconostoc lactis, Leuconostoc mesenteroides, Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus plantarium, and Lactobacillus casei. All the isolates inhibited the growth of the four pathogens used, survived at 4% concentration of NaCl, MgSO4, KNO3, NaNO3, MnSO4 and 3% bile salts used. They exhibited low surface hydrophobicity, survived in the acidic and temperatures of the media used.