The aim of this study was to isolate and phenotypically characterised lactic acid bacteria (LAB) from samples of raw (cow, goat) and traditional fermented milk product (nono).The assessed characteristics of LAB as indexed in Bergeys Manual of Determinative Bacteriology are cellular characteristic (Gram staining), growth at pH 4.5 and 9.6, growth in 5% NaCl, production of ammonia from arginine, tolerance to temperature 15 and 45oC, starch hydrolysis, and fermentation of sugars test. Fifty-five LAB were isolated and identified as Pediococcus acidilactici (15), Lactobacillus plantarum (29), Lactobacillus brevis (4), Lactobacillus casei (4), and Lactobacillus fermentum (3). Four species of the Lactobacillus isolated from nono samples were identified as Lactobacillus casei, Lactobacillus brevis, Lactobacillus plantarum and  Lactobacillus fermentum while Pediococcus acidilactici was isolated from raw cow and goat milk.  Lactobacillus plantarum was the dorminant organism with the highest frequency occurrence of 52.7% while Lactobacillus fermentum had the lowest (5.5%).  Lactobacillus species are normally found in fermented milk product which could be of great importance in food industry.

The aim of this study was to identify and evaluate the physiological studies of lactic acid bacteria from native raw cow milk. Cow milk samples were collected purposively from four different locations in Ibadan. The proximate analysis, pH and acidity of the milk samples were examined using standard procedures. Lactic acid bacteria (LAB) were isolated, characterized, and identified using both morphological, biochemical test, and Analytical profile index (API) system. The identified LAB were subjected to various physiological conditions such as growth at different temperature (15, 30, 45°C), pH (4, 6, 8) and NaCl concerntrations (4, 6, and 8%).The heterotrophic counts ranged between 3.1 ×107to 4.2 ×107CFU/mL and lactic acid bacteria counts ranged from 2.2× 107 to 3.8 × 107 CFU/mL. Thirty-five LAB isolates were randomly picked and identified as Lactobacillus (57.15%), Streptococcus (14.29%), Leuconostoc (8.57%), Pediococcus (8.57%), Lactococcus (5.71%) and Enterococcus (5.71%). The LAB isolates were further identified as Lactobacillus plantarum, Leuconostoc mesenteriodes, Lactococcus lactis, Lactobacillus acidiophilus and Lactobacillus bulgaricus based on API 50 test kit, and were able to grow at different physiological paramaters. This study shows that Lactobacillus strains isolated from raw cow milk had better physiological attributes. These LAB could be recommended for further assessment such as evaluation of probiotic potential properties and genomic analysis.

Aim: This work was carried out to investigate the influence of Lactic Acid Bacteria (LAB) on organoleptic quality and proximate composition of yoghurt, and viability of starter cultures in yoghurt. Methods: The LAB starter cultures were selected based on their ability to produce diacetyl and lactic acid. Results: Lactobacillus caseiN1 produced the highest quantity (2.72 g/L) of diacetyl at 48 hrs of incubation while Pediococcus acidilacticiG1 had the lowest amount (0.50 g/L). The pH of produced yoghurt ranged between 4.40 and 5.58 while the corresponding lactic acid contents ranged between 0.70 and 0.96 g/L. Yoghurt produced with cow milk inoculated with L. PlantarumN24 and L. BrevisN10 had the lowest pH (4.40) at significant level of P≤0.05. Yoghurt with mixed culture of L. PlantarumN24 and L. PlantarumN17 had the highest protein content (5.13%) while spontaneous fermentation (control) produced the least (0.48%). Yoghurt produced from cow milk inoculated with L. PlantarumN24 and L. PlantarumN17 was rated best with overall acceptability (9.0) during first day of storage while the commercial yoghurt (5.8) and spontaneous fermentation (6.8) had least overall acceptability at P≤0.05. Conclusion: Yoghurt samples stored in refrigerator had more viable LAB counts for a period of 21 days while the samples stored at room temperature had a day count except for yoghurt produced with cow milk inoculated with L. plantarumN24 which retained its viability at the second day. The yoghurt produced with selected LAB starters are better than commercial yoghurt in terms of sensory properties, proximate composition, pH and viability.

Aim: This study investigated the cultural method and 16S rRNA gene analysis to reveal the composition and diversity of lactic acid bacteria (LAB) from dairy origin (spontaneous fermented cow milk) in Nigeria. Methods: Six dairy samples which includes two raw cow milk, two raw goat milk and two fermented cow milk (nono) were collected and subjected to standard microbiological investigation using both cultural and molecular methods. The dairy samples were cultured on MRS media, and the isolates were identified using physiological and biochemical parameters. DNA of four selected probiotic LAB isolates from nono were amplified using PCR while the amplicons were electrophoresed in agarose gel, pre-stained with ethidium bromide and characterized by 16S rRNA gene analysis. The result of the DNA sequencing were analyzed using NCBI BLAST.  Results: A total of 55 presumptive LAB were isolated. Twenty nine (29) Lactobacillus plantarum representing 52.7%, Pediococcus acidilactici 15(27.2%), Lactobacillus casei and Lactobacillus brevis 4(7.3%) while Lactobacillus fermentum 3(5.5%) were recorded respectively. Result of the gel electrophoresis revealed DNA size of approximately 1500bp. The selected probiotic LAB from nono used in this study were confirmed as Lactobacillus plantarum N17, Lactobacillus plantarum N24, Lactobacillus brevis N10 and Lactobacillus casei N1 based on 16S rRNA gene sequence analysis while the phylogenetic analysis revealed a 98-100% similarity with a high homology level which affirms the strain of the organism. Conclusion: This study has demonstrated the diversity of LAB existing in dairy samples known as fermented cow milk (nono) which could be harnessed as valuable sources for LAB isolation and potential probiotic organisms.